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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.

Archive for the Michigan tag

USDA releases new plant hardiness zone map

December 11, 2023   •   Leave a Comment

The 2023 plant hardiness zone map is based on 30-year averages (from 1991 to 2020) of the lowest annual winter temperatures at specific locations. It is divided into 10-degree Fahrenheit zones and further divided into 5-degree Fahrenheit half-zones. The 2023 map incorporates data from 13,412 weather stations compared to the 7,983 that were used for the 2012 map.

Plant hardiness zone designations represent the “average annual extreme minimum temperature” at a given location during a particular time period (30 years, in this instance). Put another way, the designations do not reflect the coldest it has ever been or ever will be at a specific location, but simply the average lowest winter temperature for the location over a specified time. Low temperature during the winter is a crucial factor in the survival of plants.

USDA 2023 Plant Hardiness Zone Map

As with the 2012 map, the new version has 13 zones across the United States and its territories. Each zone is broken into half zones, designated as “A” and “B.” For example, zone 6 is divided into 6a and 6b half zones. When compared to the 2012 map, the 2023 version reveals that about half of the country shifted to the next warmer half zone, and the other half of the country remained in the same half zone. That shift to the next warmer half zone means those areas warmed somewhere in the range of 0 to 5 degrees Fahrenheit. However, some locations experienced warming in the range of 0 to 5 degrees Fahrenheit without moving to another half zone.

The annual extreme minimum temperature represents the coldest night of the year, which can be highly variable from year to year, depending on local weather patterns. Some changes in zonal boundaries are also the result of using increasingly sophisticated mapping methods and the inclusion of data from more weather stations.  

Temperature updates to plant hardiness zones are not necessarily reflective of global climate change because of the highly variable nature of the extreme minimum temperature of the year, as well as the use of increasingly sophisticated mapping methods and the inclusion of data from more weather stations.  Consequently, map developers involved in the project cautioned against attributing temperature updates made to some zones as reliable and accurate indicators of global climate change (which is usually based on trends in overall average temperatures recorded over long time periods).

https://planthardiness.ars.usda.gov/

ELSEWHERE: How plants survive a Michigan winter

Filed Under: Clippings Tagged With: Michigan, tool, USDA, USDA releases new plant hardiness zone map, winter

Deadline nears for Michigan Big Tree Hunt contest

August 8, 2022   •   Leave a Comment

ReLeaf Michigan, the only statewide non-profit tree planting and education organization in Michigan, has launched its 15th biennial Michigan Big Tree Hunt contest. The contest, which offers prizes for identifying the biggest trees in Michigan, is open to participants of all ages.

The largest trees in the state can be found anywhere: a backyard, a local park, or a hiking trail. ReLeaf Michigan awards certificates and prizes for the largest tree submitted from each county, for the overall largest tree in different age groups, and for potential state champion trees. Even if the tree submitted is not as large as the currently listed state champion of that species, it’s important to still submit, since the current champion may have died or since been removed.

ReLeaf Michigan started the Michigan Big Tree Hunt in 1993 to celebrate our state’s beauty and create a fun way to gather information about Michigan’s biggest trees. The contest is an opportunity for all age groups to help track these vital historical living landmarks.

More contest details and the entry form are available at www.bigtreehunt.com. Entries are due by August 19, 2022. For questions not answered on the website, please email bigtreehunt@releafmichigan.org or call 800-642-7353. 

Filed Under: Clippings Tagged With: big tree hunt, deadline, Michigan

Mountain pine beetle quarantine enacted in Michigan

January 11, 2021   •   Leave a Comment

Damage caused by the Mountain Pine Beetle in British Columbia, Canada. (Photo: Jonhall / Wikipedia)
Damage caused by the Mountain Pine Beetle in British Columbia, Canada. (Photo: Jonhall / Wikipedia)

The Michigan Department of Agriculture and Rural Development (MDARD) is working to protect Michigan’s pine trees from a potentially devastating pest: the mountain pine beetle. One of the most destructive forest pests in North America, it is known for outbreaks that have killed millions of pine trees in the western United States and Canada.

According to MDARD Director Gary McDowell, “Mountain pine beetle hasn’t been detected in Michigan yet, but we’re taking the necessary, proactive steps to ensure our pine resources are here for generations to come,” said McDowell. The state’s new “Mountain Pine Beetle Exterior State Quarantine” regulates the movement of pine forest products with bark including logs, stumps, branches, lumber and firewood originating from a number of impacted western states.

The beetles affect pine trees by laying eggs under the bark and introducing a blue stain fungus. The joint action of larval feeding and fungal colonization kills the host tree within a few weeks of successful attack. As beetle populations increase, or as more trees become stressed because of drought or other causes, the beetle population may quickly increase and spread.

Mountain pine beetle has expanded its range, moving northward and eastward. The expansion is attributed to warmer winters, which allow more beetles to survive. Michigan’s pine resources are at risk of attack, including white pine, jack pine, red pine, Austrian pine, and Scots pine. Learn more about the quarantine here. 

Filed Under: Clippings Tagged With: Austrian pine, jack pine, Michigan, mountain pine beetle, pest, red pine, Scots pine, White Pine

State of Michigan seeks help finding disease-resistant survivor elms

August 3, 2020   •   Leave a Comment

A century ago, elegant, vase-shaped American elms shaded neighborhoods with their lacy, arched canopies. Today, many of those trees are dead, skeletal husks—a legacy of the destructive Dutch elm disease. The fungal disease, spread by bark beetles, slowly wiped out most American elms after being introduced in the early 1900s.

However, the American elm’s story isn’t over. Midwest forest health experts are working to stage a comeback, and they need your help. Have you noticed any large, healthy American elms in your area or when out hiking in the forest? Those “survivor elms” might be tolerant of Dutch elm disease. If you are in Michigan’s colder climate zones (zone 5 and colder), you especially are encouraged to report these trees. Currently, there are no Upper Peninsula reports and very few northern lower Michigan reports. It’s important that these zones are represented, because it helps provide a clearer picture of where disease-resistant elms may be.

Several Midwest state natural resource agencies and the U.S. Forest Service are working together to identify such locations. They plan to collect branch samples for propagation (the process of growing new trees from a variety of sources), with the goal of developing a seed orchard suitable for future reforestation efforts in northern areas.

Eligible elms must be:

  • An American elm (not an imported species).
  • At least 24 inches in diameter.
  • Disease-free.
  • Naturally grown, not planted or treated with fungicide
  • Within 1 mile of Dutch elm disease (indicated by nearby dying/dead elms).

If you come across one of these trees, record its location and diameter at 4.5 feet from the ground. Submit the observation to the survivor elm website.

Ask MG: Why are my elm leaves are turning yellow and wilting?

Related: More on Hybrid Elms from Michigan State

Filed Under: Clippings Tagged With: dutch elm disease, elms, Michigan

Janet’s Journal: What makes a good quality garden center?

September 30, 2019   •   2 Comments

Good garden centers don’t have to carry everything. In fact, I prefer it when they stick to doing a superb job with plants. The coral bark maple (Acer palmatum ‘Sango Kaku’) that reflects the bridge color came from a local Michigan nursery.
Good garden centers don’t have to carry everything. In fact, I prefer it when they stick to doing a superb job with plants. The coral bark maple (Acer palmatum ‘Sango Kaku’) that reflects the bridge color came from a local Michigan nursery.

Where’s a good place to buy…? It’s a simple question, ending in the name of a flower, tree, tool or material used in the garden. When people ask, I know they want a simple answer, such as, “Flo’s Flowers on the corner of Main and Fifth Street.” Yet there’s a lot that goes into the definition of a good garden center.

First things first. Michigan is, in general, a great place to buy just about anything for the garden. I travel to garden for clients in other regions, speak at conferences, and for fun. Some people make it a habit to sample regional cuisine in their journeying. I check out garden centers. My count is now 18 states and 5 countries shopped, yet Michigan’s nurseries remain top on my list, with equals but no betters.

Perhaps we can thank our long-established garden centers for that, for setting the bar high for all who set up shop here more recently. Maybe it’s the savvy of a few managers who are influential in the field, who lead the way in taking the best of what they see and bring it here to us. Or it may be a combination of many factors including customer sophistication and demand. Regardless of why, I’m very glad that it is the case and hope that you, too, recognize and respect it.

I am most likely to become a regular buyer at a nursery if the staff understands what will happen to its plants out “in the field.” For instance, experienced staff know that they must remove, or advise that the buyer remove, tight ties such as these on a dawn redwood’s trunk. That staff knows their end of the business, that the ties may have been necessary in production or shipping, but they also know they will kill or permanently injure the tree over time.
I am most likely to become a regular buyer at a nursery if the staff understands what will happen to its plants out “in the field.” For instance, experienced staff know that they must remove, or advise that the buyer remove, tight ties such as these on a dawn redwood’s trunk. That staff knows their end of the business, that the ties may have been necessary in production or shipping, but they also know they will kill or permanently injure the tree over time.

When a garden-wise staff is in charge of up-potting or rewrapping woody plants like this laceleaf Japanese maple that have outgrown their temporary garden center containers, they know to remove any cords that remain from the original wrapping. Through their own experience, or working with returning customers and failed plants, they’ve learned that if they don’t take off girdling cords, they may be hidden by the new cover, planted with the tree, and eventually cause its death.
When a garden-wise staff is in charge of up-potting or rewrapping woody plants like this laceleaf Japanese maple that have outgrown their temporary garden center containers, they know to remove any cords that remain from the original wrapping. Through their own experience, or working with returning customers and failed plants, they’ve learned that if they don’t take off girdling cords, they may be hidden by the new cover, planted with the tree, and eventually cause its death.

Show me the way to my prize 

Now, on to specifics. The first thing I look for when I walk into a garden center that’s new to me is organization. Can I tell where to look for the item I’m seeking or is the layout such that I have to find someone and ask for help? If you think that’s a given, that’s because you’re from Michigan and you’re spoiled.You won’t often find here the unfathomable clutter that sometimes confronts and confounds me on buying trips in other states. I look for guideposts as soon as I walk in, which may be signs with arrows, maps of the store layout, or tall and easily seen markers that point the way to “Annuals,” “Shade Trees,” “Pest Control,” or “Water Garden Supplies.”

As a seasoned gardener I may be able to discern an organization by looking at the items that are grouped together: “Oh, these are all annuals, so I won’t look for perennials here,” or “Since everything there looks woody and tall, that must be where all the trees are.” But that leaves a lot of room for error. For instance, I may decide that the vine I’m looking for isn’t in stock at an establishment when in fact it’s there, mixed into the section I decided was “Shrubs” but the management has in fact assembled to display all of its “Tall things for privacy.”

Don’t roll your eyes. I’ve seen that kind of organization, and if it’s defined it’s fine. Having shopped in garden centers where the wares were arranged like the initial assembly of goods donated for a rummage sale, I truly appreciate the garden center manager who not only flags me to a spot with a banner proclaiming “Vines” but also sets up placards within the vine collection saying “More vines inside in the Tropical section.”

I can get past a lack of organization, or any one other item on the list I’m presenting you here, so long as the garden center measures up or excels in other categories, the second of which is product labeling.

Love those labels

Those who garden with me have heard me rail as we plant, about “All these blasted tags!” I gripe about them, but I can’t live without labels. Imagine shopping in a place where the plants do not bristle with identifying sticks, wear adhesive labels on their pots, or sport plastic bracelets.You can’t? Then you’ve chosen or been blessed with good garden centers so you can’t know the frustration of walking aisle after aisle without a clue of what you’re looking at, or the disappointment of growing something selected from a group in which only one front-row pot was marked, only to find a year later that it does not bloom the color, aspire to the size or live up to the character described on that marker.

What makes a good label? Common and scientific name, at the minimum. Given those, I can determine for myself the other things I wish could be on all labels: ultimate size, flower color, season of bloom, and any other significant seasonal interest such as fall color or winter berries.

All of the garden centers I love have books available for use by salespeople and interested customers. When I find that the variety of viburnum or species of soapwort for sale at that establishment is not quite the one I set out looking for, I can check for myself, right then and there, to see if the substitution would be a good one. Michael Dirr’s Manual of Woody Landscape Plants and Allan Armitage’s Herbaceous Perennial Plants are two mainstays of garden center reference materials that also include specialty catalogs and binder-collected magazine articles.

Even though it takes time to figure out if I should go with an alternate, that’s fine by me because it’s part and parcel of my third criteria for a good garden center: choices.

Organization! It’s what we need, especially when time is short during spring planting season, so that we can walk into a garden center and be certain that over here are the groundcovers, and over there are the dwarf conifers. Although we can make good guesses about organization based on appearances, signs or maps that confirm the whereabouts of various items are what make a passable garden center, great.
Organization! It’s what we need, especially when time is short during spring planting season, so that we can walk into a garden center and be certain that over here are the groundcovers, and over there are the dwarf conifers. Although we can make good guesses about organization based on appearances, signs or maps that confirm the whereabouts of various items are what make a passable garden center, great.

How can a buyer know that their garden center sells a reasonable size for the price? Buy some test plants from several sources, depot them and see if they have grown to just fill the pot (daylily, center), have been held too long so that they’ve become rootbound (ornamental grass, left) or were too-recently up-potted so that roots have not yet filled the container (right). No grower can achieve perfection in every one of hundreds of crops, but I know to buy from the ones who most frequently achieve the full-but-not-rootbound stage.
How can a buyer know that their garden center sells a reasonable size for the price? Buy some test plants from several sources, depot them and see if they have grown to just fill the pot (daylily, center), have been held too long so that they’ve become rootbound (ornamental grass, left) or were too-recently up-potted so that roots have not yet filled the container (right). No grower can achieve perfection in every one of hundreds of crops, but I know to buy from the ones who most frequently achieve the full-but-not-rootbound stage.

I’m in heaven when I can choose

A wide variety of plants, and various sizes of plant, impress me and keep me coming back.Did you know that garden centers here carry plants that I have not been able to find in Chicago, Boston or Los Angeles, even though they would be great additions to gardens there? Are you aware that our homegrown growers are on the cutting edge of new varieties and resurrected heirlooms? Take it from me, they are. I often drive to Massachusetts or Illinois to work, rather than fly, so I can take plants with me.

Does that mean that we should expect every good garden center to carry everything? No way, no possible way. There are 23,979 species listed in Hortus Third: A concise dictionary of plants cultivated in the United States and Canada. No one carries everything. It’s remarkable enough that growers hereabouts manage to grow five or six hundred different species well enough to sell. So it’s never a mark against a garden center that it doesn’t carry a particular plant.

What good garden centers do carry is a mix of the tried and true alongside the exciting and new. They stock trees and shrubs that are good for ornament as well as those that make a fine hedge or groundcover. They know their perennials well enough to feature more of the ones that they know experienced gardeners will like: non-invasive, long-interest species that may be so slow-growing that they’re little more than a collection of leaves after a year or more of growing in the pot, as well as the ones that novices must have: fast-growing, even thuggish creatures beautiful enough in bloom to catch the shopper’s eye.

The best carry plants in various-sized containers. There, I can cut my costs on one item by buying four-inch pots while splurging on another in a fifteen-gallon tub. The people who work at that good garden center, the ones who decide what to stock, understand that sometimes I need things with tiny root balls that will adapt more quickly to tough spaces under trees or on dry slopes, and at other times I need the same plants in more mature sizes for immediate fill.

Quality, of course, but second chances mean more

Of course it’s a requirement that a good garden center have quality plants, and if an establishment meets the other criteria here, it’s likely it has them.

It takes time to learn all there is to distinguish a good plant from a bad one, and along the way you will buy a bad plant or two. My evaluation of a garden center includes plant quality but accepts that living things will sometimes fail. So my measure of excellence puts more weight on grace in the face of trouble. If a plant fails and there is a warranty, does the seller honor that with good cheer, intelligent questions to determine the cause and helpful suggestions? Then that’s a good garden center.

Notice that I say “if” there is a warranty. Personally, I don’t believe in guaranteeing living things. If a garden center offers a guarantee, fine, but if they offer a reduced price on purchases without guarantee, I’ll take the discount because in fact I am the only guarantee that plant has. It’s up to me to find a place for it where it will get what those good reference books say it needs to thrive, to plant it properly, then check it regularly to see if it’s doing well, and to diagnose problems before they become terminal. If I return to a grower for advice, employ his or her suggestions and don’t see improvement, it’s my responsibility to follow up with more questions, just as I would with a medical doctor for a physical problem.

At a garden center worth shopping, the staff will work with me to resolve problems. Sometimes we’ll win, sometimes we’ll lose, but there will be no hard feelings either way as long as those on the retail end give it an honest go.

Variety is a big factor in garden center rating. No one business can stock every plant but if it’s good it will carry both the tried and true, such as pines and junipers for foundation planting, and the new and exciting, such as this sculpted Scots pine and Chinese juniper trained as a small tree being readied for shipping at a wholesaler.
Variety is a big factor in garden center rating. No one business can stock every plant but if it’s good it will carry both the tried and true, such as pines and junipers for foundation planting, and the new and exciting, such as this sculpted Scots pine and Chinese juniper trained as a small tree being readied for shipping at a wholesaler.

Sure, you can order by mail. But why bother if everything is available locally? Very rarely do I order by mail, since Michigan’s garden centers are stocked so well. A friend complained to me that he could find the plant he sought at just one mail order firm and it was very pricey. Within half an hour of making some calls, I found it locally for less.
Sure, you can order by mail. But why bother if everything is available locally? Very rarely do I order by mail, since Michigan’s garden centers are stocked so well. A friend complained to me that he could find the plant he sought at just one mail order firm and it was very pricey. Within half an hour of making some calls, I found it locally for less.

Please understand me

That’s my final measure of a good garden center, whether the people who work there understand what it is to garden. Do they know their plants only as they are in the pots or do they know them as mature and even old inhabitants of a landscape or garden?

It’s not necessary that everyone on staff is a gardener, but there should be enough of them, in positions of influence, that everyone on staff recognizes that quality as one to aspire to. When new employees see, hear and feel in every aspect of their work that experience counts, they are more likely to seek it themselves, to respect it in their customers and to learn who on staff they should turn to when they need to tap it. At the finest garden centers, by design or chance, the experts on staff are people who can discuss a plant’s maintenance, honestly admit its faults and recommend companion plants. They can also say “I don’t know” with the assurance that comes from glimpsing the vastness of the gardening world, and “I’ll check on that for you” in a way that sets an example of good service for everyone around them. Those who know plants are special, and in Michigan they are the cream of the crop.

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

Filed Under: Janet’s Journal Tagged With: garden center, Michigan, quality, selection

The Michigan Big Tree Hunt Contest deadline is approaching

August 8, 2019   •   Leave a Comment

big-tree-hunt-0719
ReLeaf Michigan, a statewide tree planting and education nonprofit, started the Michigan Big Tree Hunt in 1993 to celebrate our state’s beauty and gather information about Michigan’s biggest trees.

The Michigan Big Tree Hunt Contest, sponsored by ReLeaf Michigan, closes on September 3, 2019. All Michiganders are encouraged to find a Michigan big tree and enter it into the contest. Grab a friend or family member and hunt for the big trees that surround us every day in parks, on nature trails, or in our own backyards.

When the contest closes, certificates and prizes will be awarded for the largest tree submitted from each Michigan county, the largest tree found by a youth hunter (15 and younger) and adult hunter (16 and older), the largest eastern white pine found, and for potential state champion trees.

ReLeaf Michigan, a statewide tree planting and education nonprofit, started the Michigan Big Tree Hunt in 1993 to celebrate our state’s beauty and gather information about Michigan’s biggest trees. Contest entries provide potential state champion trees to Michigan’s Big Tree Registry as well as the National Register of Big Trees.

To enter your big tree or to learn more, visit www.bigtreehunt.com.

Filed Under: Clippings Tagged With: big tree hunt, Michigan, ReLeaf

Boxwood blight is detected in Michigan

January 12, 2019   •   Leave a Comment

Boxwood blight, a serious fungal disease that attacks boxwoods, has been detected for the first time in Michigan. The disease was found in Oakland County in three separate locations: a landscape firm, a homeowner’s yard, and holiday wreaths for sale at a retail store. The Michigan Department of Agriculture and Rural Development (MDARD) was also notified by the Wisconsin Department of Agriculture, Trade and Consumer Protection that infected boxwood may have been sold at other retail locations in Michigan.

“Boxwood blight is a devastating disease that has caused significant losses to homeowners and the nursery industry in states that already have the disease,” said Gina Alessandri, director of MDARD’s Pesticide and Plant Pest Management Division.

Boxwood blight produces dark brown leaf spots and causes rapid defoliation that sometimes kills young boxwoods. Boxwood blight first appeared in the 1990s in the United Kingdom and is now widely distributed in Europe. In the United States, the disease was first found in 2011 in Connecticut, North Carolina and Virginia, and has since spread to more than 24 states. Boxwood blight affects all species of boxwood. However, some species and cultivars are more susceptible than others. American boxwood and English boxwood are highly susceptible. This disease also affects the related shrub sweetbox, as well as pachysandra, a well-known groundcover. Boxwood and pachysandra are commonly used in commercial and residential plantings throughout Michigan.

Wreaths displayed outdoors are a potential concern if they are exposed to the elements. The biggest risk comes when people dispose of the infected wreaths after the holidays. MDARD recommends that anyone who has a wreath containing boxwood plant parts should consider it infected and dispose of it by burning or, even better, double-bagging and including it with their trash for deposit in a landfill.

Alessandri advised that anyone who suspects that they have plants infected with boxwood blight should contact their local MSU Extension office.

Filed Under: Clippings Tagged With: boxwood, Boxwood blight, fungal disease, Michigan

Janet’s Journal: Troubled times for the white pine, Michigan’s state tree

April 3, 2018   •   5 Comments

It is important to differentiate between white pine decline, and normal fall color, shown here.
It is important to differentiate between white pine decline, and normal fall color, shown here.

A healthy white pine is full and dark green.
A healthy white pine is full and dark green.

Many people in Michigan have noticed the yellowing and thin appearance of white pines that have stood sentinel and provided shade for decades. Some who didn’t recognize those earlier symptoms will see the first sign of this region-wide white pine problem as a dead tree.

What horticultural professionals have noticed in the Midwest, including southern lower Michigan and some areas further north on the mitten, is best described as white pine decline.

Decline is reduced vigor, below-normal functioning and slower growth in a tree when those symptoms can’t be attributed to a specific disease or insect. Trees in decline may fall prey to insect or disease problems because they are weak, but those are additional complications rather than causes of decline.

A tree may decline for many years. If its situation doesn’t improve, it may exhaust its lifetime starch reserves and begin to exhibit dieback—which looks just like it sounds and often ends in death.

I first noticed white pine decline in the mid 1990s. Many white pines yellowed suddenly, alarmingly and at least one 40-year-old tree on a property I garden died. Based on the positions of the most afflicted trees relative to northwest winds and open ground, and a severe winter that had just passed, I attributed the problems to cold-related root damage. Others came to the same conclusion and experience since then seems to support this.

When placed side by side, braches from stressed and unstressed pines exhibit noticeable differences.
When placed side by side, braches from stressed and unstressed pines exhibit noticeable differences.

Advanced dieback has occurred on this white pine tree.
Advanced dieback has occurred on this white pine tree.

Do you remember February, 1996? The white pines do! On the night of February 2-3, temperatures from the Great Plains to New England dropped to lows never seen before or not seen for 40 years. That week, the outbreak of Arctic air set nearly 400 record daily minimums and at least 15 all-time lows in the eastern U.S. Wind chills of -50 and -100 degrees were common.

In southeast Michigan, the mercury plummeted 15 to 20 degrees in just a few hours on a night when there was not even a trace of snow to insulate the soil. Branches and trunks of some plants died, and the frost knifing suddenly and deeply into the unprotected soil killed roots even on hardy, established plants.

This healthy branch shows the normal retention of needles for three years.
This healthy branch shows the normal retention of needles for three years.

By spring, gardeners would be mourning the loss or severe damage of thousands of decades-old Japanese maples, and finding privet hedges, rose of Sharon shrubs and even stalwarts such as old junipers dead or killed to the ground. Plants hurt but not killed would begin the slow process of regenerating roots and limbs only to be socked with drought years, one after another.

Shallow-rooted plants like white pine may have been worst hit. Left with fewer roots than they should have, they were not likely to take up enough water and nutrients to fuel regrowth. They were in trouble even if drought had not begun to compound the loss.

Six years later, my tally sheet of all the white pines I see regularly in my travels and those I tend reads this way: Some of the first-affected died and many are still struggling. Some which did not initially show symptoms developed them during subsequent drought years. Only a few recovered. Very few escaped all damage.

This white pine, next to the spruce on the right, is yellow and thin—signs of decline.
This white pine, next to the spruce on the right, is yellow and thin—signs of decline.

In its bulletin, “Decline of White Pine in Indiana,” Purdue University Cooperative Extension reported, “white pine decline… has been a problem for many landscapes in Indiana. …Declining trees usually look a pale green, or even yellowish, compared to healthy trees. Needles are often shorter than normal; sometimes the tips of needles turn brown. Needles from a previous season often drop prematurely, giving the tree a tufted appearance.

“With loss of needles, the tree has a reduced ability to produce the energy it needs to survive…

“With severe or compounding stress factors, the tree may gradually decline and eventually die. Decline may be gradual or rapid, depending on the number and severity of stress factors.”

University of Missouri Extension made similar reports like this one from August, 1999: “We have received many white pine samples into the Extension Plant Diagnostic Clinic this year… from mature white pines, about 20 to 30 years old that are in a state of decline. …Other Midwestern clinics have also seen (this) and have been unable to explain most cases of decline…”

“We therefore believe… that the problems we are seeing with white pine may be related to environmental factors and site conditions… such as heat, stress, drought, flooding and sudden extremes in temperature and moisture.”

Note that experts don’t lay full blame on the cold but on a combination of causes. Ironically, reliable cold and snowier winters may have worked in some trees’ favor.

Missouri, Indiana, Ohio and the southeasternmost part of Michigan, which have all seen many white pine problems since the 1996 freeze and subsequent droughts, are south of white pine’s native range. Since a species’ native range is delineated at least in part by climate, we know that something about the weather in our area is probably not optimal for white pine. A record-breaking warm-up that came after the 1996 cold snap may be one of the climatological events these trees can’t handle. Two weeks after the freeze, all across the area affected by decline, temperatures jumped into the 70s, 80s and 90s. For the most part, white pines growing where there was the usual reliable snow-cover or where the warmest air didn’t reach, fared better.

What happened to the white pines was outside current experience, on a scale so broad that few had the perspective to be able to recognize it. Now that we look back and know how long a tree has been declining which we just noticed this year, we can wish we knew more earlier, but it won’t get us anywhere.

So if you have a troubled white pine, have it inspected by an arborist. Rule out disease and insect problems. Give it the help it needs to fight any secondary problems. Do what you can to alleviate underlying stresses.

Establish a regular watering routine and fertilize the tree in early spring to see if it responds. Aerate the soil if it’s compacted. Be pleased if the tree reacts positively, but be realistic about its chances and your needs. Many of these trees are years past their point of no return. Even those which respond positively to treatment may take many years to recover.

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

Filed Under: Janet’s Journal Tagged With: decline, Janet Macunovich, Janet’s Journal, Michigan, Southeast, White Pine

Ask MG: Growing apples in Michigan

March 7, 2018   •   Leave a Comment

What are the causes of apples dropping from trees prematurely while still very small? Is malathion a safe, readily available treatment for apple trees after the petals fall? Can you recommend a book for growing apples in Michigan? D.E.

Premature fruit drop can be natural, environmental, or pest-related and it takes some careful observation to determine which category yours falls into. An early apple drop before the fruit has matured may be the result of an overproduction of fruit by the tree. The plant simply cannot support the continued nourishment for such a vast number. Profuse flowering and extensive pollination can cause this overproduction beyond what the tree can sustain. Subsequently, it “sheds” a few pounds of excess fruit to conserve energy in a natural thinning process. Some fruit tree growers will even manually thin a tree to increase the quality and size of the final product, beating the tree to the punch.

Premature fruit drop can be environmentally stimulated by unfavorable conditions like frost, excessive heat or cold, or drastic changes in humidity. Living in Michigan, any of those conditions are quite possible in the flower to fruit cycle. Since symptoms can also be soil-related, it is important to check your regularity of watering and that the proper nutrition is offered the tree at the root zone. A soil test geared toward fruit tree production would zero in on those nutrients and their correct proportions. You can obtain a soil test kit from your county’s MSU Extension.

Another environmental occurrence is herbicide drift. Never apply herbicides in windy or dead calm conditions. Dead calm is often associated with a phenomenon known as temperature inversion. Contrary to popular belief, spraying under such conditions can actually increase drift distance. The culprit spray may be several yards away, making it difficult to pinpoint the source.

Pest-related fruit drop occurs much later in the season, when the fruit is very near maturity. So insect pests are probably not the reason for your premature drop.

As for the application of malathion, a readily available insecticide for homeowner use, proceed with caution. Make certain you correctly identify the pest, that the insect pest exists on your apple trees and that it is doing damage before arbitrarily applying any insecticide. Malathion is particularly effective against leafrollers and codling moths, which can damage apples, and must be applied at specific intervals. All label instructions and cautions should be followed to the letter if applying it yourself. A better choice would be to contact a certified arborist for an accurate diagnosis and treatment. Oftentimes beneficial insects can be eliminated from nature’s cycle in the homeowner’s fury to protect their plants.

For Michigan apple growing information, contact the your county’s MSU Extension and obtain how-to bulletins on tree fruit. For a nominal cost, you will get targeted, science-based information on Michigan climate, the best apple varieties, and proper techniques to successfully grow apples in Michigan.

Filed Under: Ask MG Tagged With: apple, growing, malathion, Michigan

Cranbrook Gardens to offer free admission

July 25, 2017   •   1 Comment

cranbrook-sunken-garden-0717For the third year, admission is free to Cranbrook Gardens through October 31, 2017, courtesy of its sponsors. The gardens are open daily from 9:00 am to 5:00 pm for self-guided visits.

Spanning 40 acres around historic Cranbrook House, the former home of Cranbrook’s founders, George Gough and Ellen Scripps Booth, Cranbrook Gardens is known for its formal gardens featuring fountains, statuary, lakes, streams and extensive plantings. Highlights include the Sunken Garden, Herb Garden, Bog Garden, Native Plant/Wildflower Garden, Reflecting Pool Garden, and Sundial Garden.

The Sunken Garden, a formal garden surrounded by fieldstone walls, was originally established by the Booths as a vegetable garden. They used the crop to feed the people living and working on their estate a century ago. The Booths lowered the garden to extend the growing season. In later years, the Booths moved the vegetable garden to another location and transformed the original space into a flower garden. Today, Cranbrook House & Gardens Auxiliary’s captivating layouts for the Sunken Garden attract thousands of visitors each year.

Since there is no cost to enter the grounds, guests are encouraged to visit the Sunken Garden and all the gardens often to discover firsthand how they evolve from spring through fall. Although the gardens are free, tours of Cranbrook House and special events require paid admission, and donations are always welcome. All proceeds help support the preservation of Cranbrook House & Gardens, a National Historic Landmark. For more info, click here.

Filed Under: Clippings Tagged With: bloomfield hills, Cranbrook, cranbrook gardens, free admission, Michigan, sunken garden

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