Michigan Gardener

SIGN UP to stay in touch!
We will send you occasional e-mails with gardening tips and information!


Digital Editions

Click on the cover to read now!

  • Home
  • Departments
    • Ask MG
    • Books
    • Clippings
    • Garden Snapshots
    • MG in the News
    • Janet’s Journal
    • Plant Focus
    • Profile
    • Raising Roses
    • Thyme for Herbs
    • Tools and Techniques
    • Tree Tips
  • Garden Event Calendar
  • Resources
    • Alternatives to Impatiens
    • Garden Help
    • Soil and Mulch Calculator
    • Public Gardens
  • Web Extras
  • About
    • About Us
    • Editorial Content
    • Privacy Policy
    • Contact Us

PLEASE NOTE: In the autumn of 1995, we hatched the idea for a free, local gardening publication. The following spring, we published the first issue of Michigan Gardener magazine. Advertisers, readers, and distribution sites embraced our vision. Thus began an exciting journey of helping our local gardening community grow and prosper.
After 27 years, nearly 200 issues published, and millions of copies printed, we have decided it is time to end the publication of our Print Magazine and E-Newsletter.

Identifying and controlling Lecanium scale

April 4, 2023   •   Leave a Comment

There are several species of lecanium scales (Parthenolecanium) throughout North America. European fruit scale and oak lecanium scale are the ones most commonly found in Michigan on maple, birch, redbud, quince, beech, ash, ivy, fruit trees, locust, arborvitae and many others.

This young pin oak (Quercus palustris) has yellowing leaves. This can indicate an iron or other nutrient deficiency, a problem that affects pin oaks in alkaline soil. Nutrient deficiencies weaken the plant and make other problems more likely to occur.
This young pin oak (Quercus palustris) has yellowing leaves. This can indicate an iron or other nutrient deficiency, a problem that affects pin oaks in alkaline soil. Nutrient deficiencies weaken the plant and make other problems more likely to occur.

Description

Mature female lecanium scales are less than 1/4 inch in diameter, rounded, and reddish to brown in color. Males are brown, flying insects, and have two long, tail-like, whitish hairs. Eggs are whitish, very small and may look like pollen. Young nymphs (crawlers) are flat, pale white to yellow with legs, eyes and antennae. Older crawlers are flat, brown and have less noticeable legs and antennae.

Lecanium scales have three (in the female) or four (in the male) stages of development (called “instars”). Males develop into pupa that are a pale peach, covered by a translucent waxy coat. Females overwinter in the second instar on 1- to 3-year-old twigs. They mature in the spring, lay many eggs (1,500 or more) in May or June, and then die. Their dead bodies protect the eggs beneath. Crawlers hatch out in June or July, migrate to the underside of leaves along the mid-rib and veins to feed. In late summer they migrate back to the twigs and develop their waxy coating to overwinter. There is one generation per year.

Damage

Damage caused by lecanium scale includes smaller flower size, discolored leaves, and premature leaf and fruit drop. In heavy infestations there can be dieback of twigs and branches, and stunted growth. Scale feeding weakens a plant but is rarely life threatening on its own. They produce a great deal of honeydew, a sticky excrement that can coat almost anything under the tree. A sooty mold may develop on a honeydewed surface. This can discolor the branches and trunk so they are nearly black.

However, a closer look at the pin oak shows tiny bumps along the twigs.
However, a closer look at the pin oak shows tiny bumps along the twigs.
The bumps are oak lecanium scale. They are covered with a sticky substance called honeydew.
The bumps are oak lecanium scale. They are covered with a sticky substance called honeydew.
Peeling back the soft shell reveals that the insect is dead, its eggs have hatched, and the crawlers have migrated to the leaves.
Peeling back the soft shell reveals that the insect is dead, its eggs have hatched, and the crawlers have migrated to the leaves.

Control

Control of this scale comes first and foremost from proper cultural practices that keep the plant otherwise healthy and vigorous, so it is able to withstand scales’ feeding and produce natural defenses and deterrents to their reproduction. Avoid stressing or overfertilizing the plant. If pesticides are determined to be necessary, timing of the application is everything.

The crawlers are the most vulnerable stage. There are different approaches to deciding when to apply a pesticide. You can use a calendar approach, applying on a reference’s recommended date. With this approach, control is difficult because weather is so influential in insect development and yet so variable from year to year.

Another approach is to use indicator plants to time your control. In his book Coincide: The Orton System of Pest Management, Don Orton says when smooth hydrangea (Hydrangea arborescens ‘Grandiflora’), bottlebrush buckeye (Aesculus parviflora), and yucca (Yucca filamentosa) are blooming, lecanium scale crawlers will be present.

The crawlers settle on the underside of the leaves along the midrib and veins.
The crawlers settle on the underside of the leaves along the midrib and veins.

Lastly, there is the most reliable approach: go look at the plants to see when the crawlers are present.

There are natural predators that attack lecanium scale such as ladybeetles, lacewings, mites and wasps. However, as Dr. Dave Smitley from Michigan State University says: “These soft scale insects go in cycles and rarely cause any harm to landscape trees. The scale infestation sometimes becomes worse when the trees are sprayed for other reasons…because the insecticide kills predators and parasites that keep the scale insects under control.”

A horticultural oil may be used in the early spring to smother the females on the twigs. Also, a systemic with the active ingredient imidacloprid can be used as a soil soak to allow the tree to take in the pesticide before the crawlers emerge. Remember, before applying a pesticide, ALWAYS read the label to ensure proper use for that insect and that plant. 

Article and photos by Steven Nikkila, www.gardenatoz.com.

Filed Under: Plant Patrol

Follow these five steps to grow fabulous roses

April 4, 2023   •   Leave a Comment

Roses are just like people—they need just five things to thrive:

  1. Sun
  2. Air
  3. Food
  4. Water
  5. Love

Mother Nature can handle the first two needs (sun and air) by herself. But she needs your help with the second two (water and food) in order for your roses to survive. You are the sole provider of the last need (love). And it’s that one that spells the difference between roses that simply survive, and those that thrive.

Let’s consider each of these needs:

Sun. Roses are sun-loving plants. Typically roses need at least six hours of full, direct sunlight daily and will do better if they receive more.

For areas that receive between 4 and 6 hours of direct sun, select five-petaled roses. These are roses with a lower petal count and, in general, the lower the petal count, the more shade a rose will tolerate. As a group, hybrid musk and antique alba roses are fairly shade tolerant—mainly because they have simple blooms. 

Typically roses need at least six hours of full, direct sunlight daily and will do better if they receive more.
Typically roses need at least six hours of full, direct sunlight daily and will do better if they receive more.

Air. Roses like good air circulation to keep their leaves dry and to prevent fungal diseases. However, avoid exposure to strong winds. Consider the most rugged roses, like rugosas and Canadian explorers, for your cottage on the Great Lakes. Otherwise, plant your roses where they will enjoy gentle breezes. Remember this if you plant near a wall or solid fence.

Remember, roses grow quickly, which means you should thoughtfully consider the spacing between bushes. Follow this rule of thumb: roses generally grow to be as wide as they are tall. So, roses expected to be four feet tall should be planted about four feet apart, as measured from the center of one bush to the center of the next.

Hybrid tea roses can be planted closer together, while antique and shrub roses should be placed a little further apart. Remember, too, that climbing roses need lots of room. Plant them at least 6 to 8 feet from neighboring climbers.

It’s a common misconception that roses shouldn’t be planted near other types of plants. In truth, they can be part of an integrated landscape provided neighboring plants don’t crowd them and prevent good air circulation.

Food. Roses are heavy feeders and appreciate richly amended soil. They are adaptable to soil type. They’ll thrive in sandy soil if you feed them frequently, and in clay soil if they have good drainage. The solution to sandy-soil and clay-soil problems is the same: organic amendments. Many municipalities produce wonderful compost from the grass clippings collected from homeowners. Usually this compost is free for the hauling.

Apply your first fertilizer in late April or early May. Slow-release fertilizers need only be used once or twice a year. Organic options should be used every 4 to 6 weeks. In any event, your last fertilizer application should be in mid-August, so that your roses ease into dormancy before the first heavy frosts.

The commonly available rose fertilizers with systemic insecticides should be avoided because they will kill earthworms. Treat insect problems as they occur—you don’t need to “nuke” your entire garden to eliminate a few aphids or budworms when targeted attacks will be sufficient. Also, foliar-feed fertilizers give your roses a nice snack, but they are too quick-acting and transient to be used exclusively.

Water. Roses like lots of water, but not wet feet. In other words, be sure the plants are in a well-drained soil. We simply do not receive enough natural rainfall in Michigan for roses to thrive, which begs the question, how much is enough? Some will tell you 1 or 2 inches per week. However, it really depends upon your soil type and drainage. The goal is to keep the soil near the rose roots evenly moist. This means you’ll need more water in sandy soil than in clay. Try installing a rain gauge near your roses so you can see exactly how much water they are receiving.

The belief that you shouldn’t permit rose leaves to get wet is a myth. In our nursery, we watered our roses exclusively with overhead watering. We found that it helped wash off powdery mildew and insects. It helped that we watered early in the morning so that the leaves dried as the day came on. This prevented fungal diseases that can form when leaves are wet for an extended period or overnight.

Most residential in-ground irrigation systems are optimized for turf grass and do not provide enough water for roses. You can supplement these systems by hiding a soaker hose under the mulch around your roses. Your irrigation contractor may recommend a special drip irrigation circuit for roses, but be prepared to check the emitters frequently—clogging is a common problem.

A good organic mulch, such as finely ground pine bark, pine needles or garden compost will help the soil retain moisture and reduce the need for frequent watering.

Love. Spend a little time with your roses, deadheading spent blooms and checking the moisture content of the soil at their roots. That way, while you are enjoying their beauty, you’re likely to notice “conditions” before they become “problems.”

Roses can be the stars of your garden, so plant where you can admire them frequently—their blooms are abundant and fabulous. Follow the guidelines presented here, and you’ll be amazed at their display!

Nancy Lindley was the co-owner of Great Lakes Roses in Belleville, MI.

Related: Simple steps to keep roses healthy for the summer

Elsewhere: Downy mildew control on roses

Filed Under: Raising Roses Tagged With: grow fabulous roses, growing, roses

April is an opening movement in a spring symphony

April 4, 2023   •   Leave a Comment

April is like the opening movement of a slow and gentle spring symphony, a cluster of crocus here, a ripple of daffodils there, the soft mist of blue scilla under the oak, with diminuendos of delicate wildflowers, and the occasional somber note of hellebores.

Neighbors, whom we have not seen all winter, emerge from hibernation on the first warm day, and we tell each other how glad we are that we are still alive and that spring is finally here.

For me though, spring pleasures begin much earlier, when the first cut daffodils and tulips appear in the stores. Every week I buy a bunch of tulips and watch them change from tense, tight creatures to voluptuous stars, opening wide and saluting the world. This week’s lot are scarlet, and when I first put them in water they were all droopy, but after a night’s drinking they pulled themselves to attention like so many soldiers and grew bigger, puffed up with grandeur. Now they are flaunting themselves like ballerinas bowing to an audience and the outside base of their petals is gold. The leaves have turned from dark green to paler and are curving in sympathy with the blossoms. By week’s end, they will be worn and weary and it will be time to choose the next color—orange or pink or yellow.

Spring pleasures begin for me much earlier when the first cut daffodils and tulips appear in the stores.
Spring pleasures begin for me much earlier when the first cut daffodils and tulips appear in the stores.

Sometimes too I buy bright yellow daffodils and the house is filled with instant sunshine, or I bring in a bunch of dead-looking forsythia twigs from the garden and in no time at all they burst into golden stars. For an extra treat, spend an afternoon at the Detroit Institute of Arts with the Dutch flower paintings of spring flowers, including those beautiful bicolored, ruffled tulips (purple with green and orange with cream) as well as iris, primrose and narcissus. The colors are so vivid they look as though they have just been painted.

But what do you do in February when icy winds whip the garden and everything is brown and dreary and lifeless? I dove into plant catalogs and was particularly excited by a golden smoke tree (Cotinus coggygria ‘Golden Spirit’), a lovely lemon-leaved weigela, and some stunning new hydrangeas. Once again I became determined to try the various daphnes for leaf, flower and fragrance. One of the easiest is ‘Carol Mackie’ (Daphne x burkwoodii). Consider the liberal use of outstanding foliage interplanted with both perennials and annuals, giving a tropical feel to the garden, even in colder areas. 

My next spring pleasure is visiting the garden stores to see what is new in pots, window boxes, garden furniture, sculpture and tools. There is everything from tiny flower pots, old tools and wire planters to sundials, wrought iron and wicker furniture, as well as sculptures from both here and overseas. Old is not necessarily better, so browse around and find wonderful European glazed pots, terra cotta from Greece, willow seats and arches from England, or wonderful American garden furniture and furnishings. I rather like the pseudo terra cotta, fiberglass planters that look like the real thing but are lightweight, and more importantly for our climate, frost-resistant so you don’t have to haul them into the garage in the fall. They make marvelous containers, particularly for shrubs and perennials.

While you are looking, check out the new seeds and bulbs. More and more organic vegetable seeds are available as well as wildflowers, perennials and annuals. There are poppies to delight us: the Shirleys, Icelands, Flanders and Orientals, and I noticed a double dark red, almost black poppy. Look for black in hollyhocks, pansies, fritillarias, and even very dark purple roses and almost black peonies. If you want to keep up with the English royals, plant a black and white garden like Charles did at his glorious Highgrove property.

So what is left for early spring? Reading catalogs, starting vegetable and annual seeds, ordering plants, reading, dreaming and waiting. It’s almost time to get out into the yard and even as I write this in March there are signs of warmer weather. The migrant birds are back, red wing blackbirds, the titmouse, swans, geese and herons. Last week in Ann Arbor I saw a carpet of snowdrops under a tree, and there is a scattering of crocus, aconites and dwarf iris (Iris reticulata) in the garden.

Soon the first fresh Michigan asparagus will be ready and all the abundance, glory and color of spring stretch ahead of us in days of endless sun, flowers, light nights and warmth. What bliss!

Christine Jamieson gardens in Oakland County, MI.

Filed Under: Garden Essay Tagged With: april, spring, spring pleasures, spring symphony

Is it OK to water my houseplants with softened water?

March 31, 2023   •   Leave a Comment

You can’t taste any sodium in softened water, but it is there, and it builds up in the container mix, eventually killing the plant if you do nothing.

No, you cannot water with softened water. That, however, is the water that some people have, so they need to find ways to avoid damaging their houseplants. The damage results from the softening salt that replaces the naturally-occurring calcium and magnesium in the water with sodium. You can’t taste any sodium, but it is there, and it builds up in the container mix, eventually killing the plant if you do nothing.

First, explore other options. Your plumbing system should have an outlet valve that allows you to draw water before it enters the softener, so you can get “hard” water there. Before using it, let that water sit in an open container overnight to allow the chlorine from a municipal water system to evaporate and for the water to come to room temperature. Another option is to use a rain barrel to collect and use rainwater. In some areas rainwater is very acidic. If yours is, add a teaspoon of ground limestone to each 6-inch diameter container of potting medium to counteract the acidity.

If none of these options are viable, use the softened water and take the following steps. Always use containers with drainage holes and never let the containers sit in a pool of the softened water. Use a houseplant fertilizer that contains trace minerals, and use it “weakly, weekly.” For instance, if the label says one teaspoon of fertilizer per quart of water monthly, then use 1/4 teaspoon weekly. Divide the recommended dosage so that you use an appropriately reduced amount every time you water. Then, every time you water make sure the amount of water is enough to go entirely through and run completely out the bottom so that it is carrying away any built-up sodium. As time goes by, the soft water sodium causes the potting mix to harden as the salts accumulate. Watch for this symptom and repot as often as it happens. Usually once a year is enough, but you must wash away all of the potting mix from the roots using tepid water and start over with new mix. That routine will do as much as possible to reduce the damage to the houseplants.

If any of your houseplants are in huge containers, just do what you can. I have a two-wheeled dolly to lift and wheel them out to the patio to sit in the summer rain sometimes to leach out their soil. In the winter my ficus likes to be leached by taking a shower in my walk-in shower stall. That’s one way to leach away the yucky stuff from a monster pot. Put your thinking cap on, and you will find a way.

As for annuals in outdoor containers, soft water may not have time to do much damage in only one summer growing season, as opposed to houseplants that are expected to grow and thrive for many years. Fertilize the same “weakly, weekly” and water thoroughly every time you water to leach out the salts from the previous watering. Then use new container mix each season and any build-up of salts should be eliminated in the process.

Answer by Martha Ferguson.

Related: What is the white build-up on houseplant pots?

Filed Under: Uncategorized Tagged With: houseplants, softened water, water, Watering

Springtime: Reassurgence in the garden

March 16, 2023   •   Leave a Comment

Will I ever in my lifetime feel sure at spring? After decades of observation, I still find myself on pins and needles wondering about certain plants and events in the springtime. Shouldn’t this one be back up by now? Weren’t there more of that one last year—did I take some out or what happened? What I did last fall—has it helped or hurt?

One part of me wants to figure it out and stop this worrying and wondering. Another thrills at the suspense, grows on the nervous tension, and learns a bit each year. Here I’ll tell you about some of the recurring questions I’ve put to rest. If you are like me—in need of reassurance at this resurgent season—these things, at least, you can be sure of…

Assurance #1: The bees will be there—on time, every time

A garden’s bloom season may begin on a different calendar date each year, as winter wraps up early or late. Yet on the day the first flower opens in your garden, bees will be there to sip its nectar. I was awed by the bees’ appearance the first time I saw my earliest crocus (C. minimus) on its first day. Since then, having seen it happen many times, the awe has mellowed but never left me.

I am assured bees will find the first flower, or that aphids will appear on the first succulent spirea shoots, and locust plant bugs will emerge as their host plants break bud. Each insect species has honed its timing through thousands of generations, so that they dance to the same tune as the plants they depend upon.

In both plant and insect, internal meters begin to run at the freeze that ends one season, accumulating time toward the wake-up bell for the next. On each day that temperatures rise above 40, for however many hours they hover there, insect eggs and larvae move forward in their development and plant cells chip away at chemicals that built up during fall as insurance against any resumption of growth before a safe time. In a related heat-registry, overwintering adult insects reckon safe emergence time. We humans have observed and recorded this timing in total degrees and hours, and converted it to “degree days.” At agricultural university Extension offices where such information is vital, we start our own meters at fall’s end to mark these units of time and say, for example, “Ah ha, 220 degree days have accumulated. Usually that happens about May 7 but this year it’s early…at any rate, it’s now time to look for honey locust plant bugs appearing from their wintering state.”

It’s an exquisite timing, particular to every region and microclimate. Degree days stack up more quickly one block uphill from me in Jack’s yard, which sheds its cold air downslope to pool in mine. So his crocus may open sooner than mine, and so too will the bees wintering in niches in his yard.

Do the first crocuses call the bees? Do the first bees tease the earliest flowers into opening? No, they've simply both tuned their springtime wake-up alarms to the same degree day.
Do the first crocuses call the bees? Do the first bees tease the earliest flowers into opening? No, they’ve simply both tuned their springtime wake-up alarms to the same degree day.

Assurance #2: Bugs will get ahead of you

So is it any wonder that even when we promise a favorite plant we’ll watch out for it next year, its predators find its new growth before we do? Insects and animals that rely on a plant are out there 24/7, awaiting or directly linked to their particular prey. As weekend warriors, we can’t beat that.

We can stay even by keeping sight of two facts, however. One, for most plant eaters, emergence coincides with their own plant’s new growth. Two, baby bugs are easier to kill than older, tougher individuals. Someone who told you they controlled aphids on a viburnum by, “just dousing it with the rinse water after I washed dishes,” was not telling tales even though this tactic may have failed in your yard. Apply soap (over-the-counter insecticidal soap spray or water plus dish soap) when the viburnum is just budding out and the day-old skins of its aphids will dry and split. Spray it on week-old aphids and those hardened veterans may break out loofah sponges and begin a chorus of Singin’ in the Rain.

Don’t let this news get you down. Most plants can manage despite the chewing, sucking or scraping of their usual predators. If they look worn or tattered as a result but have lost less than 20 percent of their leaf surface, they’ve suffered only cosmetic damage. That can be ignored or grown over. Meanwhile, insects such as ladybugs and lacewings that eat other insects are also engaged in the degree day dance. They’ll emerge in time to capitalize on their own prey’s development.

I do very little in the way of bug killing, but quite a bit of bug encouraging. That is, I avoid insecticide and allow insect-sheltering debris to overwinter in order to have the continued presence of species we recognize as beneficial insects. Out in a garden where hundreds or even thousands of insect species live, there are 8 or 9 species of beneficials for every 1 or 2 plant-damaging insect species. These good guys do little or no damage to plants—for instance, they may dine on pollen—but many attack, parasitize or eat other insects.

In addition, I keep my plants healthy by putting them where they can grow most vigorously. Such plants are better equipped to produce the distasteful, deterrent and downright deadly chemicals their species have devised to thwart their predators.

Butterfly bush is a tough customer if it's grown where it belongs: in a sunny, sandy, well-drained and even dry spot. Cut it all you want whenever you want—you won't kill it. However, it's likely to be dying before you even cut it back in spring if it was planted where the drainage is poor.
Butterfly bush is a tough customer if it’s grown where it belongs: in a sunny, sandy, well-drained and even dry spot. Cut it all you want whenever you want—you won’t kill it. However, it’s likely to be dying before you even cut it back in spring if it was planted where the drainage is poor.

Assurance #3: Dead wood will fool the unsuspecting eye

As plants’ internally-concocted potions can dissuade insects and grazers, so can guilt turn people off from gardening. Don’t let it happen to you.

Lots of gardeners are more concerned about the damage they themselves have done, than what insects may do. “I pruned my butterfly bush at the wrong time and killed it,” is a common cry in this crowd. Let this spring mark the end of that lament, if it’s been voiced in your yard.

I can assure you that you cannot kill a butterfly bush (Buddleia davidii) by cutting it back in early spring, even to stubs an inch above ground, even removing all its wood that was beginning to bud out.

You can, however, cut a dead or dying butterfly bush and then blame yourself. If you’re in zone 5 or a warmer (higher number) zone and the bush was healthy last fall, it will be able to grow from one-inch stubs to 4 or 5 feet tall, and quickly, too.

If the bush is not healthy—particularly if it’s being grown in soil that’s overly moist or poorly drained—its crown and roots are susceptible to rot, which takes hold during winter and consumes the live tissue as spring ensues.

Another factor to consider is that some varieties of butterfly bush are not as hardy as others. In my experience, ‘Dark Knight’ is not to be trusted, whereas ‘Nanho Blue’ can probably handle even zone 4 cold if it’s given a well-drained, sandy site.

Roses prick gardeners with guilt too. I’ve watched for decades as roses are pruned at various times and stages of development, looking for proof that we “should not prune them too early.” In one instance, I checked in throughout the season on a public garden of several hundred roses pruned by a single horticulturist over a three-week period that included the “too early” days before forsythia bloom, and saw no ill effect.

As with butterfly bush, a rose may be dead or dying by pruning time. When we learn to look at the base of stems and crown of a shrub for signs of life such as moist, green cambium under the bark and white cores in branches, we will recognize deadwood when we cut it and be free of self reproach.

Assurance #4: Slow starters will start when you give up

Something else gardeners have a tough time accepting is the lateness of plants like hardy hibiscus (Hibiscus moscheutos), butterfly weed (Asclepias tuberosa), balloon flower (Platycodon), perennial ageratum (Conoclinium coelestinum), and groundcover plumbago (Ceratostigma plumbaginoides). These plants, big contributors to late summer bloom, all take their sweet time to emerge, avoiding the cold weather their new growth cannot tolerate by remaining dormant many degree days later than other plants.

So it’s a sure thing in spring that we will give up on one or another of these, give in to the urge to buy more plants, plant something “to replace” what we assume has failed, and soon after have two plants duking it out over the same space.

In fact, degree days may not be the only determinant of a slow starter’s emergence from winter rest. It could be that honest despair is a tonic to them, for they almost always pop up the day after a gardener has given up all hope, pouring his or her sense of loss down on that ground.

Ironically, this error can lead to a better garden. If you chance to buy the right type of plant and set it to grow where you believe the balloon flower or other supposed failure lies, you may produce a fine double-up. That is, if you plant an early riser that tends to nap through summer (early blooming bulbs, for instance), or a tap-rooted, spring-blooming species where a shallow-rooted character tallies (oriental poppy with hibiscus, for example), or a shallow-root spring bloomer with a deep-root sleepyhead (Sedum spurium with balloon flower), the two may go on happily for years together.

Balloon flower is late to emerge, but worth the wait.
Balloon flower is late to emerge, but worth the wait.
Hardy hibiscus (H. moscheutos and its hybrids) often sleeps in until late May. It doesn't mind another plant's foliage occupying its air space in April and May, and its shallow roots can straddle deep-rooted spring bulbs such as daffodil and quamash (Camassia).
Hardy hibiscus (H. moscheutos and its hybrids) often sleeps in until late May. It doesn’t mind another plant’s foliage occupying its air space in April and May, and its shallow roots can straddle deep-rooted spring bulbs such as daffodil and quamash (Camassia).

Assurance #5: You’ll estimate wrong about the mulch you need

Another thing that goes on for years is ordering too much or too little mulch. We might get it right at first guess, then think, “But didn’t I use that much last year, even before adding the two new beds?” Or we might announce our intention to another member of the household who undermines our confidence by asking, “That much? Are you sure you need that much?”

Since too much or too little is more rule than exception, cover your bases. When you have the mulch delivered, don’t let it be dumped right in front of the garage door. Not unless you want to hear long-suffering sighs from family members for weeks, along the lines, “I wishI could put my car in the garage!“

Likewise, in a move to ward off an unwelcome impact on your days that can follow the spreading of too little mulch, always begin mulching in beds that you see every day. Leave the farthest beds for last. Then, if the mulch runs out before all bare soil is covered, the exposed ground will not glare at you every day for the week or two that inevitably separates mulching opportunities one and two.

When the mulch truck arrives, temper your optimism about how long it will take to spread. Don't dump the pile where it will block your garage door.
When the mulch truck arrives, temper your optimism about how long it will take to spread. Don’t dump the pile where it will block your garage door.

Assurance #6: The weather will conspire against you

One reason mulch follow-up rarely follows right on the heel of a mulch shortfall is the uncooperative nature of weather. If you chance to be gifted with a clear, cool day on the weekend or the day off work you chose for mulching, the next two picks you make will turn out to be filled with rain or sleet. Unless you garden in the Desert Southwest where weather reports are unnecessary because every day is sunny and dry, buy some rain gear. If you use it only once, you will still be glad. There’s a lot to be gained simply from telling the tale of working in the rain. Be sure to take a picture of you behind the wheelbarrow in the rain suit.

Another way that weather will do you in, but one in which you will probably be a co-conspirator, is in killing dahlias, elephant ears and caladiums. Although these roots you harvested last fall stored best through winter at 50 degrees, they won’t grow well now in soil that cool.

It’s a mistake to plant them outdoors before crabgrass season—about June 1 in my neighborhood—when the soil reaches 60 degrees. Once the tuber or corm you plant softens in the ground preparatory to sprouting, it’s susceptible to fungal attack in cold soil. Once the shoot begins to grow, the plant’s even more likely to be injured or infected. Such a plant may die, or limp into summer as a weakling.

If you’re itching to do something with those dahlia tubers or corms of elephant ear or caladium, divide any clumps now. Cut away any rotted sections. To be viable, a dahlia division must have a bit of last year’s stem included.

Then put just an inch of moist potting mix into a pot that’s eight inches deep or deeper, set the root in and add just enough potting mix to cover it. Put the pot in a warm place—no light needed—and check on it every few days. Your aim should be to keep it barely moist and to note when the shoot begins to grow. Once you see that, add more moist potting soil an inch at a time. Let the shoot show itself, cover it under an inch of potting mix, let it poke its tip up again and blanket it once more, until it reaches the top of the pot. Then put the pot into full sun. This process keeps you occupied for the last few weeks of unsettled weather and keeps the plant warm while it develops a stout shoot.

I hope you kept your dahlia, canna, caladiums and other clumps of tender perennials intact over winter. Divide them only when it's time to replant. Undivided clumps (dahlia, at left) store better with less chance of rot, just as a bruise-free potato or whole onion stores best. The canna (right) was cut before storage and has rotted sections.
I hope you kept your dahlia, canna, caladiums and other clumps of tender perennials intact over winter. Divide them only when it’s time to replant. Undivided clumps (dahlia, at left) store better with less chance of rot, just as a bruise-free potato or whole onion stores best. The canna (right) was cut before storage and has rotted sections.
When you divide, cut away any damaged section. This canna is more tolerant of cool soil than some tender perennial roots. Yet, why set it out early when the plant's best role is as a late summer filler?
When you divide, cut away any damaged section. This canna is more tolerant of cool soil than some tender perennial roots. Yet, why set it out early when the plant’s best role is as a late summer filler?
Elephant ears (Colocasia) don't grow well and may be stunted all summer if planted into cool soil. Delay outdoor planting of those that love warmth (caladium, dahlia, elephant ear, etc.) until the ground reaches 60 degrees, in June.
Elephant ears (Colocasia) don’t grow well and may be stunted all summer if planted into cool soil. Delay outdoor planting of those that love warmth (caladium, dahlia, elephant ear, etc.) until the ground reaches 60 degrees, in June.

Assurance #7: Blue and pink hydrangeas will disappoint you

Hydrangea failure is another weather-plus-gardener problem. Mophead hydrangeas (H. macrophylla) are not reliably bud hardy in continental zone 5. That means their roots and sometimes their stems survive winter but the buds often do not.

The problem there is that this species spends the latter half of summer preparing a bud that will be in shape to finish its growth and bloom the following July. If those buds, located at the tips of branches, die or are cut off, the plant begins over again but flowering-branch development is a lengthy process. It is very unlikely the shrub will be able to produce a blooming shoot between now and when fall ends its season.

Sometimes winter kills the buds. You can tell right now if that happened. Consider yourself fortunate and the plant placed well if the bud at the tip of the branch is alive. You’ll know that’s the case if it’s plump and moist. Such a bud probably just pushed its protective scales aside to begin to grow again. If it’s dried out, dead or gone, don’t expect any bloom. Your placement of the plant is to blame. You can try shifting it to a spot in your garden where a warmer, more humid microclimate prevails in winter.

You see, even if a blue or pink hydrangea’s buds made it through winter, they’re not out of the woods yet. Weather steps to the fore. Often, as surviving buds open in spring, they’re killed by late frost. If that happens, loop back two paragraphs and read “If those buds…” because the weather’s kicked the plant back to that start-over point.

How is this dismal news reassuring? It is because it can save a gardener months of suspense that end in disappointment. Look now and be reassured by the condition of the tip buds whether there’s any chance for bloom. If there is, keep a cloth sheet on hand and cover the shrub to trap some ground warmth on frosty spring nights. If you’re attentive it may yet keep its tips and bloom.

The tip bud on a mophead hydrangea branch. It survived winter and is beginning to grow in spring, but has one last hurdle to clear: late spring frosts.
The tip bud on a mophead hydrangea branch. It survived winter and is beginning to grow in spring, but has one last hurdle to clear: late spring frosts.

Final reassurance: Revelation will come

Whether it’s an “ah-ha” based on something you read in a magazine, a connection you make because your nose knows something about soil temperature that cannot be expressed in words, or the sounds you hear from birds reach a place in your conscious where natural cues rank themselves in mysterious but meaningful groups, you will learn and have fun this spring. I’m sure of it.

Article by Janet Macunovich and photos by Steven Nikkila, www.gardenatoz.com.

RELATED: Springboard into the garden season

Filed Under: Janet’s Journal Tagged With: Janet Macunovich, Janet’s Journal, spring, springtime

What is a good flowering shrub for a fence line?

March 7, 2023   •   Leave a Comment

I am looking for a flowering shrub to go along a 6-foot high white fence. I would like it to grow to 3 feet wide and 2 to 3 feet tall.

There are several possibilities that can be maintained to size with relative ease. Planting in front of a white fence reflects heat on the plant. That heat can accelerate flower production but also dry out the soil sooner. Flowering shrubs need a minimum of 6 hours of sunlight each day and consistent watering. Use mulch to minimize water loss. The soil should be loamy and enriched with compost. 

Flowering shrub - Dwarf Korean Lilac (Syringa meyeri 'Palibin') Photo: Bailey Nurseries
Dwarf Korean Lilac (Syringa meyeri ‘Palibin’) Photo: Bailey Nurseries

Dwarf Korean lilacs (Syringa meyeri ‘Palibin’) bloom mid to late spring with highly fragrant pink flowers. Shear after bloom to maintain the 3- by 3-foot dimension. The dark green glossy foliage provides a nice contrast to the white fence and can behave as a deciduous hedge. If you want a little height, arrowwood viburnums (Viburnum dentatum) have strong upright growth and flat white flowers in spring. Blue Muffin (‘Christom’) grows 3 to 5 feet tall, with blue-black berries that persist if not eaten by birds, and shows orange to burgundy red foliage in fall. Like the lilacs, hand pruning and thinning after bloom will keep the height at the desired level every other year.

Examine the wonderful single and double Knock Out roses. Introduced in 2000, they have become a mainstay in the summer garden, producing flowers continuously from spring until hard frost. Extremely hardy and disease-resistant, they live up to their name.

RELATED: What is a good choice for a privacy shrub?

ELSEWHERE: Viburnum dentatum

Filed Under: Ask MG Tagged With: fence, flowering, flowering shrub, shrub

What caused holly berries to not appear in the fall?

February 18, 2023   •   Leave a Comment

Holly berries
Although the holly plant is basically a male plant, their flowers and subsequent pollen are necessary for the fertilization of the flowers on the female berry-producing plants.

For years, our holly bushes have been lush with fall holly berries, but not last fall. I think they got their fair share of water during the summer heat wave. Any thoughts?

Think back to April 2012 and what happened with the late frost and freezing temperatures at the end of the month. Many of our beloved spring-flowering trees were heavily damaged at a critical time in fruit formation. The holly bushes were no exception. Even though the buds form in the fall of the previous year, April would have been the time these tiny flowers in the leaf base on male plants would have been opening. Many flowering shrubs and trees suffered great damage last spring due to the sudden cold temperatures. Michigan’s cherry and apple industries were significantly impacted by the cold snap.

Although the holly plant is basically a male plant, their flowers and subsequent pollen are necessary for the fertilization of the flowers on the female berry-producing plants. If they aren’t there, the female flowers are not pollinated and there is no berry. Maintaining a consistent watering routine early in the summer as well as during drought periods will also prevent premature berry drop. Covering plants when a freeze is posssible can substantially decrease the loss of flowers and future berry production.

Related: What are some suggestions for deer-resistant plants?

Elsewhere: Winterberry: Michigan’s native holly

Filed Under: Ask MG Tagged With: berries, fall, holly

Why do cracks on tomatoes occur while still on the vine?

February 3, 2023   •   

Resistant varieties come in all sizes and types. ‘Mountain Spring’ (a large red), ‘Sweet Million’ (a small-fruit variety), and ‘Mountain Gold’ (a yellow tomato) are just three selections that are not so prone to cracking.

Cracks on tomatoes that circle the stem end or stretch down from the stem end can be very annoying. They not only deform the beauty of the fruit, but also leave it susceptible to rot. The cause of cracks on tomatoes is generally a growth spurt caused by a prolonged drought. The solution is to provide your garden with adequate and consistent water. You need to water to keep the soil evenly moist. In Michigan, we can have full weeks of rain followed by a month of nothing.

If droughts are common in your immediate location, then besides monitoring the watering, try to look for and select a crack-resistant variety next season. Resistant varieties come in all sizes and types. ‘Mountain Spring’ (a large red), ‘Sweet Million’ (a small-fruit variety), and ‘Mountain Gold’ (a yellow tomato) are just three selections that are not so prone to cracking.

Answers compiled by Martha Ferguson, and contributed by Beverly Moss, Michelle Dunham and Chuck Tyrrell.

RELATED: Tomato blossoms are disappearing

ELSEWHERE: Tomatoes exhibiting cracks this summer

Filed Under: Ask MG Tagged With: cracking, cracks, tomato, tomatoes, vine

Choosing the right location and container for SunPatiens

January 18, 2023   •   Leave a Comment

In my back yard, I planted SunPatiens in a container that gets sun in the morning and afternoon and some in the evening. These plants thrived, with little fertilizer and just periodic watering. On the other hand, the SunPatiens that I planted in the front (facing west) wilted and lost their leaves rapidly. I watered them daily, sometimes twice. I removed them from their pots and found root rot. So I bought some fresh plants, drilled more drainage holes, but the same thing happened. Any ideas on what the problem is?

Your descriptions of the health of the same plants in the two different locations seems to tell the story. Typically, container placement is different in the front of the house as opposed to the back. More than likely your backyard containers are away from the house walls and windows, perhaps out on a patio or deck where they can be seen from the house, but not against the house, maybe even out in the lawn or near garden beds. The containers in the front are probably nearer to walls and windows to be seen and enjoyed on the approach to the front door. Buildings absorb, reflect, and intensify heat. To make matters much worse, new windows with low-E glass or older windows that have been coated with a UV ray coating really intensify the heat that is reflected. The plants are being heated to an extreme. You water more, causing the root rot, but the death rays of heat continue to zap the foliage. Increasing the number of drainage holes in those containers is helpful to prevent root rot, but still you must water more and more as the reflected heat continues to hit the plants. The only real prevention is to move the containers a safe distance away from walls and windows. Easier said than done probably. Another complication to consider is the size and shape of the pots. The large container in the back will hold more moisture longer, a smaller container dries much faster, such being the case with the original hanging containers. The wider and lower a container is, the slower the water drains away. The taller and narrower the container is, the faster it drains, even if the two containers are filled with the same amount of potting mix.

Related: Pinching off annuals when planting

Answers compiled by Martha Ferguson and contributed by Beverly Moss, Michele Dunham, and Martha Ferguson.

Filed Under: Ask MG Tagged With: annuals, Container, sunpatiens

Belle Isle conservatory temporarily closed for major renovations

December 14, 2022   •   Leave a Comment

The Anna Scripps Whitcomb Conservatory is undergoing $10 million in renovations, which required the closure of the conservatory and grounds in mid-November 2022.

The Belle Isle Conservatory is undergoing $10 million in renovations, which required the closure of the conservatory and grounds in mid-November 2022. The work completes the final phase of a comprehensive plan to revitalize the upper 60 feet of the 80-foot-tall conservatory dome in one of the nation’s oldest turn-of-the-century glass houses still in existence.

The project starts with inspection of the original steel trusses to see which need repair or replacement, the removal of lead-based paint in the upper 60 feet of the conservatory dome (also known as the Palm House), reglazing the upper dome, and updating the conservatory’s ventilation system. In addition to unique horticultural collections, the building itself is a draw for architecture and history buffs; it was designed by Albert Kahn, one of Detroit’s most celebrated architects.

In addition to unique horticultural collections, the building itself is a draw for architecture and history buffs; it was designed by Albert Kahn, one of Detroit’s most celebrated architects.

The first phase of this comprehensive renovation project, completed in 2019, included the replacement of all 20 original steel trusses. “Major renovations are needed to stabilize the building to keep the conservatory open for the next century,” said Amanda Treadwell, urban field planner for the DNR Parks and Recreation Division. “The scope of work is critical to the structural integrity of the dome, public safety and improved conditions for the plant collection.” Treadwell said such capital improvements have been long overdue. “Besides the recent renovations in 2019, there has not been a major capital investment to the conservatory since the 1950s,” she said.

The outdoor gardens will reopen in May 2023, while the conservatory is scheduled to reopen in May 2024. Throughout November and December, scaffolding and a second floor will be erected to contain the abatement work and ensure minimal temperatures are maintained for the plant collection. Similarly, an envelope wrap will surround the exterior of the dome for the duration of the work.

For more information, visit Michigan.gov/StateParksProgress.

Filed Under: Clippings Tagged With: Anna Scripps Whitcomb Conservatory, Belle Isle, Belle Isle Conservatory, detroit, Renovations

  • « Previous Page
  • 1
  • …
  • 3
  • 4
  • 5
  • 6
  • 7
  • …
  • 43
  • Next Page »

Copyright 1996-2025 Michigan Gardener. All rights reserved.