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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.

Putting flowers in compost pile

August 21, 2010   •   

I have self-seeding plants in my garden that I pull out before they go to seed and spread around too abundantly. If I pull them when they are in bloom and put them on the compost pile, will they still go to seed even though the roots are exposed and the plant is dying? I don’t want to end up inadvertently spreading the seeds through the beds when I use the finished compost.

First of all, if you pull these plants when they are still in bloom, they haven’t finished the process of making the seeds. If you miss a few and don’t remove them till after the bloom has long faded, then the seeds have formed. If you maintain a hot compost pile, one that reaches a measurable 140 to 160 degrees, the heat will not only kill many pathogenic organisms, but also self-seeding plants. A hot pile works best if it is made up all at one time and then allowed to compost completely without further additions of material. You don’t say what kind of plants these are, but you might consider deadheading to “trick” the plant into blooming again. Then you can enjoy more blossom time and get the jump on the seed-making process before it begins.

Filed Under: Ask MG

Organic matter & decomposition

August 21, 2010   •   

As organic matter (compost, mulch, etc.) is added to the garden, how do the beds not gradually grow higher? Does the organic matter decompose to literally nothing? Or do the particles just become so small that the beds’ height is relatively unaffected?

There are two actions at work. First is that the decomposition process continues after the compost has been added to the beds. A very small percentage of the matter, called humus, is left at the end of the decomposition process. As decades go by with more and more organic matter added to the beds, the soil level would increase.

The second action at work is that plants are being grown in the beds and they consume the humus along with the other elements that comprise the soil. If more organic matter is added to the beds than is consumed by the plants, then very slowly over time the beds will gradually grow higher.

Filed Under: Ask MG

Basil leaves have holes

August 20, 2010   •   

My basil is riddled with holes. I can’t find any pests hanging around the plants or on the leaves. What to do?

Basil (Ocimum basilicum) can be grown in Michigan gardens as an annual herb when the ground warms in the spring or inside year-round. Basil is grown for many purposes, including crafters using it in potpourri and dried flower arrangements. Cooks find endless culinary uses for its unique flavor, including the making of vinegars, baked goods, jellies, salads and Italian dishes. Gardeners value basil as a beneficial companion plant for many vegetables to help improve growth and flavor while providing some protection from insects. We can rub leaves on our skin and place fresh sprigs on the barbecue to repel mosquitoes or lay them on top of food bowls to stop flies from landing.

Despite all its insect repellent properties, basil itself is subject to a variety of pests, including leaf-chewing slugs, snails, Japanese beetles, rose beetles, caterpillars, thrips, white flies and flea beetles. Realizing that there are a number of pests that feed on basil, your first step will be to clearly identify which pest is causing the leaf damage before a course of action can be chosen. Slugs and their relatives hide during the day, but during the night they leave telltale slime trails to identify them after the fact. Flea beetles can hide on the undersides of the leaves, with many tiny shot holes as evidence of their presence. Most of the others are able to be observed during the day if you are vigilant.

Once identified, one or more of the solutions below will help you to successfully grow and harvest this useful, valuable herb.

  • Create a healthy environment by providing your plants with full sun and ample water. Plant in a nutrient-rich, well-drained soil.
  • Rotate plants and introduce beneficial insects into your garden.
  • Use organic controls including insecticidal soap and oils, B.t. (Bacillus thuringiensis), plant-based insecticides (pyrethrums) and diatomaceous earth.
  • Learn and practice the tenets of IPM (Integrated Pest Management).
  • A few pesticides are registered for legal use on basil, but the residue left on the plant and the chance of inhalation during application can be toxic.

Filed Under: Ask MG

Plant Focus: Hakone grass

August 13, 2010   •   

hakonechloa-macraGeorge Papadelis
Hakonechloa macra
Terra Nova Nurseries
‘All Gold’

by George Papadelis

Ornamental grasses have become increasingly popular. Few plant groups can provide winter interest, ease of care, versatility, and an enormous palette of various heights, colors, and flowers. When most people think of ornamental grasses, they imagine the classic sun-tolerant perennial species like maiden grass (Miscanthus), switch grass (Panicum), fountain grass (Pennisetum), or feather reed grass (Calamagrostis). However, many gardeners are not familiar with the more diminutive, shade-tolerant species. Lily turf (Liriope), sedge (Carex), and hakone grass (Hakonechloa) grow in shade or part shade and offer many of the same qualities as the traditional sun-loving grasses.

The Japanese native hakone grass has glossy, soft leaves that grow upright and then cascade or “waterfall” horizontally. This effect lends itself very well for use on slopes or as an edging plant. The slow-spreading clumps are not invasive. In fact, full pots of hakone grass can be difficult to find at your local garden center. High quality plants typically draw a premium price compared to other ornamental grasses. Young plants often disappoint the impatient gardener during the first season or so. However, two or three years in moist, well-drained, and fertile soil will yield lush mounds of beautiful leaves. Hakone grass turns pinkish-red each fall, then bronze, then tan during winter dormancy. The blowing, rustling leaves are pleasant all winter long until early spring when plants should be cut down to about an inch or two tall. The fresh foliage returns by late May.

hakone-grass-aureolaEric Hofley / Michigan Gardener
‘Aureola’
Hakonechloa
has no major insect or disease problems that would warrant concern. In my yard, however, rabbits feast on the spring leaves and can delay the anticipated display of an established plant. The application of an effective animal repellent can solve that problem.

Four different types of hakone grass are available and all grow about 12 inches tall. In my opinion, the species Hakonechloa macra is very underused. It has shiny, bright green leaves that work well with almost any other foliage color or texture. The popular H. macra ‘Aureola’ has gold and green leaves that glow in the shade from spring until fall. The cultivar ‘All Gold’ clearly describes its primary attributes. ‘Albo-striata’ is rarely available but has green and white bicolored leaves.

All Hakonechloas bring a beautiful texture to the shady garden that looks best when contrasted with other foliage. Ferns have fine-textured leaves that look gorgeous up against the long, linear leaves of hakone grass. The large, bold leaves of hostas are equally excellent companions. Try a blue hosta with the gold leaves of either  ‘Aureola’ or ‘All Gold’ hakone grass. Or perhaps try gold hosta with the green leaves of H. macra. The popularity of lace-leaf, red Japanese maples gives many of us an opportunity to underplant with the vibrant leaves of a gold hakone grass.

hakone-grass-columbusEric Hofley / Michigan Gardener
Hakone grass is a great perennial for the shade. Hakonechloa macra ‘Aureola’ is shown here with a hosta and variegated pachysandra.

Keep in mind that there are hundreds of flowering perennials for shade, many of which are underused. Foliage plants will usually create the foundation or backbone of the shady perennial bed. Like hostas and ferns, I can’t imagine a shady garden without hakone grass.

George Papadelis is the owner of Telly’s Greenhouse in Troy, MI.

 

Try this combination

One of the most beautiful (and useful) late summer-blooming perennials for shade is plumbago (Ceratostigma plumbaginoides). This slow-spreading groundcover is covered with fluorescent blue flowers from late July until fall on 8- to 10-inch tall plants. When temperatures drop in late September and October, the plants continue to flower but the leaves turn a lovely russet red. This plant is perfect alongside a mound of hakone grass.


At a glance: Hakone grass

Botanical name: Hakonechloa macra (ha-kone-ee-KLO-uh MAK-ruh)

Plant type: Perennial grass

Plant size: 12 inches tall, 12-18 inches wide

Habit: Layers of cascading foliage

Hardiness: Zone 5

Leaf color: Bright green or yellow; yellow, white, green variegations

Leaf size: 10 inches long, 1/2 inch wide

Light: Partial shade to shade

Soil: Moist, fertile, well-drained

Uses: Slopes, edging, shade garden, containers

Companion plants: Hostas, ferns, plumbago

Remarks: Pinkish red fall color, bronze color in winter. Cascading habit makes them great for slopes or edging. Takes 2 to 3 years to establish.

hakonechloaGeorge Papadelis
Hakonechloa turns from pinkish-red to bronze, then finally to tan in the winter.

Filed Under: Plant Focus

Plant Focus: Blue mist spirea (Caryopteris)

August 10, 2010   •   

caryopteris-worcester-goldwww.monrovia.com
‘Dark Knight’
by George Papadelis

When fall approaches, many gardeners believe it’s time to hang up the trowel and bring an end to another growing season. Fall, however, offers us many opportunities to enhance our landscape. Most plants allocate their energy to developing strong root systems in the late season. This, along with the cooler, less stressful growing conditions, makes fall an ideal time to plant. Cooler weather also means more comfortable temperatures for garden “work.” The ever-expanding palette of late-season annuals like flowering kale, flowering cabbage, dianthus, dahlias, petunias, verbenas, and so many more are increasingly available to brighten flowerless voids and refurbish tired window boxes. Let’s not forget pansies and bulbs. Fall-planted pansies will often bloom until the holidays and then begin blooming again early next spring.

caryopteris-flowerJonathon Hofley / Michigan Gardener
‘Worcester Gold’
Besides the popular garden mum, there is also an enormous selection of late-season perennials that are often underused. The list of shade lovers includes anemones, toad lilies (Tricyrtus), perennial lobelia, snakeroot (
Actaea or Cimicifuga), yellow wax bells (Kirengeshoma), certain hostas, and many, many more. The list of late-season bloomers for sunny locations is even longer and includes blue mist spirea (Caryopteris), a reliable performer and a beautiful addition to the autumn landscape.

Most blue mist spireas grow about 2 to 3 feet tall and wide, and have powdery blue flowers. Tight, one-inch clusters of tiny blue flowers develop in profusion along woody stems. Flowering lasts from mid-August well into October. The fragrant foliage of the more common varieties is a silvery blue-green, but others may be gold or green and white variegated. They thrive in any well-drained soil and prefer full to part sun. They flower on new wood, so pruning the plant in early spring to about 6 inches should yield excellent results.

Most plants that are referred to as “perennials” have stems that die down to the ground every winter. Blue mist spirea, however, is like lavender, butterfly bush (Buddleia), roses, and Russian sage (Perovskia); it develops woody stems that, to at least some extent, stay alive through the winter. In a severe winter, these stems can suffer, but a few inches of soil mounded directly over the plant’s crown in late November will insulate it. This discourages severe temperature fluctuations and reduces damage from drying winds. In spring, simply remove the soil from the plant’s base. When the new growth becomes apparent, prune away the dead stems. Additional pruning may be necessary to shape the plant and/or control its size. This same technique works well for roses, butterfly bush, Russian sage, lavender, and other vulnerable woody plants.

caryopteris-dark-nightEric Hofley / Michigan Gardener
‘Dark Knight’
Blue mist spirea is usually propagated by rooting soft tip cuttings. Some gardeners, however, will be rewarded with seedlings that develop at the base of the plant. Pollinated flowers will produce seed that is very viable but also variable. When these grow to a few inches tall, they can be transplanted to a permanent location and evaluated for potential future use.

Two readily available varieties are ‘Longwood Blue,’ with light blue flowers and gray-green leaves on plants that grow about 3 feet tall, and  ‘Dark Knight,’ which boasts similar but deeper blue flowers on slightly taller plants.

caryopteris-foliageJonathon Hofley / Michigan Gardener
‘Worcester Gold’
For beautiful golden foliage, ‘Worcester Gold’ is wonderful from spring until fall. It also has blue flowers in August and September on 3-foot tall plants. A newer gold cultivar called ‘Sunshine Blue’ has even more intensely gold foliage on 3-foot tall plants. Its amethyst blue flowers in August and September glow against its attractive foliage.

‘Snow Fairy’ is the first variegated leaf selection. It has brightly variegated green and white foliage that alone warrants the use of this plant. It produces clear blue flowers, and grows taller, to about 4 feet. Two new blue varieties include ‘Grand Blue,’ with dark blue flowers above dark green leaves on plants that only grow 2 feet tall and wide, and ‘First Choice,’ which produces rich, cobalt blue flowers on a more freely branching, compact plant that is just less than 3 feet tall.

Companion plants

caryopteris-longwood-bluewww.parkseed.com
‘Longwood Blue’
The flowers of blue mist spirea make a wonderful companion to other late season perennials and annuals. Most ornamental grasses are at their peak in September and may offer a perfect backdrop. Switch grass (Panicum) has erect, green to blue-gray stems and leaves topped by sprays of burnished bronze seedpods. Several varieties offer heights ranging from 3 to 7 feet tall, but ‘Shenandoah’ or ‘Heavy Metal’ would be the best Caryopteris partners. Shorter maiden grass (Miscanthus) like ‘Adagio’ and ‘Little Nicky’ offer silvery or pink flower plumes that blow in the wind. Feather reed grass (Calamagrostis) like ‘Karl Foerster’ offers stiff, wheat-colored plumes in June that last for almost a year on 4- to 5-foot tall plants. Fountain grass (Pennisetum) grows about 3 feet tall and produces fluffy, bottlebrush flowers of burgundy, beige, or black. All of these ornamental grasses are outstanding perennials to grow with a blue mist spirea. More importantly, each fall, ornamental grasses leave behind beautiful faded plants that last throughout the winter. These tan mounds of leaves and flowers provide even more interest when sprinkled with fresh snow or covered in glistening ice.

For a flowering blue mist spirea companion, you have many choices. Mums and fall-blooming asters come in an enormous color range and grow as low as 12 inches to as tall as 3 or 4 feet. The gold to orange flowers of Helen’s flower (Helenium) stand atop erect plants growing 3 to 4 feet tall. The goldenrod (Solidago) cultivar ‘Fireworks’ offers airy sprays of tiny yellow flowers that last throughout September. Windflower (Anemone) will thrive in sun or shade and produces masses of pink or white flowers to accent your blue mist spirea blooms.

Autumn is a great opportunity to spruce up flowerbeds and begin planning for next year’s garden. Plant some spring-blooming bulbs, think about trying some pansies, and don’t forget those mums. With these and the myriad of fall bloomers, all of us should have a spectacular September garden. A plant like blue mist spirea adds some excitement to our palette of late-season choices.

George Papadelis is the owner of Telly’s Greenhouse in Troy, MI.

 

At a glance: Blue mist spirea, bluebeard

Botanical name: Caryopteris (ca-ree-OP-tur-iss)

Plant type:Perennial

Plant size:2-4 feet tall and wide

Habit:Rounded bush

Hardiness:Zone 5

Flower color:Various shades of blue, from light to dark

Flower size:1-inch clusters

Bloom period:Late summer to fall

Leaf color:Gray-green, gold, white & green variegated

Light:Sun to partial sun

Soil:Well-drained

Uses:Perennial border

Companion plants:Medium-sized ornamental grasses, late-blooming perennials such as Helen’s flower, goldenrod, windflowers 

Remarks:Stems dieback depending on the severity of the winter (similar to Russian sage and butterfly bush). Blooms on new wood, so prune in early spring.

Filed Under: Plant Focus

Rose of Sharon winter injury

August 10, 2010   •   

We have a rose of Sharon bush and it died suddenly. It is 6 to 7 years old, and showed no signs of stress. In fact, last year, it had the most beautiful blooms ever. What could we have done to prevent this? We have 2 more of these bushes, and would hate to see this happen again! They get sunlight until late afternoon, and we are on sandy soil.

Every year the onset of spring brings with it different changes to our gardens. We can expect occasional winter die back of branches on rose of Sharon (Hibiscus syriacus). With careful spring maintenance pruning to remove the dead wood, we will still enjoy a multitude of flowers that are produced on this year’s growth. While the past winter was very cold, death is seldom the result of one problem, but a combination of conditions over the life of that plant. The best defense you have is to always remember “right plant right place,” improve watering and fertilizing practices, and keep an eye out for insects and diseases that can stress a plant and leave it vulnerable to winter kill.

Filed Under: Ask MG

Rejuvenating junipers

August 9, 2010   •   

I have neglected trimming some juniper tams under our dining room window for several seasons. They are now over 6 feet tall. Can I cut them back nearly to the ground and expect them to regrow? They have no foliage under their outer surface growth.

Junipers will not tolerate heavy pruning because they do not have latent buds below the foliage area in older wood. If branches are pruned back to older wood with no foliage, the branch stub usually dies. This fact makes it important to choose a variety of juniper that has a growth habit and mature size that will suit the planting area you have selected. The growth habits of junipers vary from low-growing ground cover varieties to large conical-pyramidal forms. You might just want to replant the area with a more suitable juniper that will require much less maintenance pruning.

Filed Under: Ask MG

Dealing with invasive perennials

August 8, 2010   •   Leave a Comment

I have a bed that was installed with landscape fabric (to prevent weeds) and rocks for mulch. Can perennials in the bed still spread invasively?

Perennials that are invasive got that reputation because they go where they want and take no prisoners. The landscape fabric may challenge them for a time. But most invasive species do their dirty deed with rhizome type roots. The fabric will keep them warm, trapping moisture, allowing them to run until the root finds a weak point. To avoid this problem, plant perennials with a clumping habit rather than a running one. Avoid those that offer “quick coverage” or those that boast “self-seeds.” That seed will sprout in the crevices between your rocks, and the roots will work through the fabric. Remember that landscape fabric is a woven plastic material that allows air and water to pass through. Weeds need sunlight to germinate. The fabric effectively prevents that. The fabric may retard the individual growth of perennials planted through the holes cut in it, but it will not prevent invasive plants from following their natural habit.

Filed Under: Ask MG

Pruning ornamental trees

August 8, 2010   •   

I have crabapple, cherry, and mulberry trees. When is the best time to cut off low-hanging, big branches? Also, can I straighten an established tree?

Prune your crabapple in fall to early spring. This is the dormancy period when major limb removal causes the least bleeding. Mulberries are also mid-winter prune candidates. Even in full dormancy, older trees may still bleed profusely. Cherries, either sweet or sour varieties, should not be pruned in winter. They are susceptible to silver-leaf disease. Pruning must be delayed until bud-burst in spring. However, if a branch is dead, diseased or damaged, it should be removed as soon as you notice it. This holds true for the crabs and mulberry as well. If you are merely pruning for convenience or aesthetics, wait until the appropriate time.

As for straightening an established tree, you need to determine why it is crooked. Are there prevailing winds, which have caused the trunk to lean? Was it improperly staked as a sapling? Is it seeking sunlight from under the canopy of an overshadowing tree? You can open up the canopy of an adjacent tree if shade is the cause. You can also prune the canopy of your leaning tree so that it appears more in proportion to itself. There are methods for forcing branches to grow in another direction. I would consult a professional arborist before attempting this on your own.

Filed Under: Ask MG

Grubs in lawn & beds

August 7, 2010   •   2 Comments

I have grubs in my lawn and flower beds. I know how to treat my lawn but I’m not sure what to do about the flower beds.

White grubs are the larvae of various scarab (or chafer) beetles, including Japanese beetles, June, and May beetles. The larvae overwinter in the soil and pupate in early spring, with adults emerging in late spring to early summer. Michigan had a long, cool spring. This stalled the emergence of the adult beetles, which are currently devouring the landscape. The adult beetles are only susceptible to repeat insecticide applications. If you find a small infestation, hand-picking and dropping them into soapy water will suffice. However, adults are present through the entire growing season. It is important to be vigilant so adult beetles do not lay more eggs in the soil. The eggs are invulnerable. The grub larvae are susceptible to several kinds of granular insecticide sold specifically for lawn treatments for grub control. You can work this granular formulation into your flower beds as well. Remember, grubs feast on roots, which means perennials and ornamental shrubs are also on the menu, along with your lawn. As you work the soil in your flower beds, you can destroy grubs and pupas as you find them. That’s one less procreating eating machine in the landscape.

Filed Under: Ask MG

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