Shrubs and Trees
Winter Damage
What winter damage is, and what to do right now to prevent it
Winter Damaged Rhododendron
Now that winter seems to be really here, it’s a good time to address the most common cause of winter damage to shrubs: wind and sun. Did you think it was cold and snow? A lot of people do, but that is a misconception. In fact snow acts as an insulator and protects plants. The real damage happens when winter wind and sun draw moisture out of plants and, because the ground is frozen, the plant’s roots cannot replace the lost moisture. Common examples of winter damage are browning of leafs, dead rhododendron flower buds, dead branches and in sever cases loss of the entire plant. Broadleaf evergreens are most vulnerable – especially Rhododendrons, Azaleas, Holly, Boxwood, Andromeda, and Mountain Laurel. To a lesser degree needled evergreens such as Arborvitae, Cypress, Alberta Spruce and Yews are also vulnerable. For the most part, deciduous plants (those that lose their leaves each fall) do not suffer winter dehydration (desiccation).
Wilt Stop: Wilt-stop is an anti-desiccant, an all natural spray that coats the greens with a thin wax that helps prevent moisture from evaporating from the needles and leaves
Two preventions that work:
Spray with an anti-desiccant
Right now - literally this weekend, when temperatures are 40 degrees or above - spray your broadleaf and needled evergreens with an anti-desiccant. The product we like best is called Wilt Stop. Spray it on the upper and lower leaf surfaces and it will provide an invisible waxy coating that will seal in moisture, protecting the plant from the drying winter winds that can cause browning, desiccation and death. This is particularly important for newly planted shrubs, container plantings, and any evergreen that is planted in an area where it is exposed to strong winter sun or wind.
Wrap with burlap
Newly planted evergreens, and those that are planted in exposed, windy areas may benefit from being wrapped in burlap for the winter. The best way to do this is to drive 3 or 4 stakes into the ground around the plant, wrap the burlap around the stakes, and staple or tie securely. If you want to protect an evergreen hedge, you can simply drive the stakes into the ground every 3 feet or so on both sides of the hedge and staple the burlap to the stakes, snug against the hedge, rather than wrap each plant individually. Evergreen hedges planted along the street may be exposed to road salt so it’s best to use a double layer of burlap for greater protection. Road salt can be very damaging to the foliage. Never use any type of plastic, as this material will heat up on sunny days, causing the foliage to burn.
Special note about Hydrangeas
Hydrangeas are also susceptible to desiccation. Flower buds that are located on the canes can also suffer winter damage. In this case, sprays and burlap are not the solution. Instead gently stuff straw or leaves in the middle of the canes, then tie up the canes and mound more straw or leaves around the outside. This cocoon should protect next years flowers from this winter’s wind and sun. Final note: do not uncover too early in the spring as tender buds could still be damaged during spring frosts.
Jean Dooley, Commercial Account Manager
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PDFFall Is For Planting Trees, Shrubs, Perennials and Lawn Seed
While it may seem that the gardening season should be over, fall is actually a perfect time to plant. Yes, things above ground may look bleak, but below ground root growth is still in full swing.
- Planting success is all about the roots.
- You can plant later than you may think.
When you plant in the fall the soil is still warm from summer. Warm soil temps encourage new roots to grow. Fall is also the time when plants naturally shift their energy from top growth to root growth. This helps plants establish faster. Rainfall is more plentiful and predictable in the fall. New plantings require moisture for optimal growth. In addition, annual weeds that compete for nutrients and moisture are finishing their life cycle, which reduces this competition. And fall’s ample rainfall encourages roots to grow more deeply. Deeper roots are better able to find water now and next spring.
Another counter-intuitive benefit to planting in the fall is the cooler air temperatures above ground. Cooler temps mean less stress and fewer pest and disease problems.
Last but not least, roots continue to grow until the ground freezes. The results are that plants that are put in the ground in the fall will have stronger roots to start off next spring. Then when summer comes, they will be better equipped to deal with heat and drought.
Some things need to be planted in the early fall
There are many plants that will thrive when planted about four weeks before the first hard frost. These plants – grass seed, turf and cool season vegetables – need to establish a root system before the ground starts to cool in late fall.
Seeds or seedlings of lettuce, radishes, broccoli and spinach can be planted in early fall. To extend the harvest later into the fall, a row cover of black plastic can be added for further protection once heavy frost arrives.
Early fall is the best time for rejuvenating your lawn or for planting a new lawn. Grass seed germinates at cooler temperatures than summer can provide. Weeds are not germinating now making it the perfect time for lawn work. Ideally, new grass seed should be planted about a month before the first hard frost predicted for your area.
Groundcovers such as Vinca or pachysandra will develop strong root systems when planted in the fall. When spring arrives your fall planted beds will be thick and full of healthy plants.
Some things can be planted even into late fall
Any perennial, shrub or tree that has been grown in a container or ball and burlapped can be planted late into the fall – right up until the time that the ground freezes. Later plantings will benefit from a protective mulch once the ground is frozen. This insulates the soil and keeps it from freezing and thawing.
Tulips, Daffodils and other spring flowering bulbs are best planted from mid-October through ground freeze. Planting too early can cause the bulbs to send up top growth at the wrong time. Planting bulbs in the fall ensures a good root system and a beautiful garden when spring arrives.
Final benefit
Savvy shoppers know that plant prices come down as the year comes to an end. Perennials are an especially great bargain because most people see a perennial that has passed and assume it’s dead. Fact is planting perennials in the fall means you’ll get a great price, and the plant will have the fall months to grow a strong root system. Next spring you’ll be rewarded with a fantastic, established plant and some extra money in your pocket to boot.
My Azaleas and Rhododendrons look dead! What can I do?
Winter Damage on a Rhododendron: Although the leaves may be brown and curled, this doesn’t necessarily mean the plant is dead. In fact in most cases the plant will rebound easily with a little TLC.After a long, cold, snowy winter like we just had, we often see damage to our shrubs and trees often called “winter kill” or “winter damage.” The most common damage is brown or dead-looking azaleas, rhododendrons, holly and other broadleaf evergreens. Most people assume cold temperatures are to blame, but it’s actually caused by dehydration. In winter, cold dry winds and bright sunshine suck moisture from the foliage of broadleaf evergreens, much like chapped lips after a day of skiing. Plus, because the ground is usually frozen and the plant is dormant, plants can’t move water through their roots back to theire leaves. The result is dehydration, browning the tips of leaves or even entire branches. The more exposed to wind and sun, the greater the damage; particularly heartbreaking when it happens to shrubs you’ve loved for 20 years or more. Yes, sometimes the plant is dead and will need to be replaced, but often winter damage only make shrubs appear dead.
How do I know if it can be saved?
Look carefully and you’ll see that the leaves may be brown and brittle but the branch may have good life. Try gently scratching the bark with a fingernail, if underneath it’s greenish and pliable it’s probably still alive. If under the bark is brown and brittle the branch is probably dead – but not necessarily the whole plant. Continue the exploration down the branches and you will probably see some life along the way. Usually I tell people to leave winter damaged shrubs alone until late May. By then you can see the new growth starting, making it easier to see and prune the brittle dead wood. In any case, don’t give up on them to soon – in early spring, winter damage often looks a lot worse than it really is! All you need is a little patience and a good organic fertilizer.
The Scratch Test: Try gently scratching the bark with a fingernail, if underneath it’s greenish and pliable it’s probably still alive. If under the bark is brown and brittle the branch is probably dead – but not necessarily the whole plant.
Holly-tone by Espoma: Use it on all broadleaf evergreens like Rhododendrons, Azaleas, Holly, Boxwood and Andromeda.
Help the recovery with a good organic fertilizer.
I can remember I had a Holly and an Azalea that turned completely brown from winter damage. Then after feeding with Espoma Holly-tone fertilizer and some warmer weather from Mother Nature both plants completely re-foliated and grew back to where they were the previous fall. This saved me the time and effort of replanting the shrub. The earlier in spring you take action the better because it will allow more time for the bare branches to re-bud and start to fill in. There are other products to choose from, but Holly-tone is easy to use and it’s worked well for me. If there is mulch around the base, just push it away to expose the soil. Scratch the soil surface a little to allow for good soil contact and spread Holly-tone around the drip line of the shrub (the area under all branches). Just follow instructions on bag for proper quantity. Then just replace the mulch, water and wait for the magic healing to begin. You may need to go back and do some tip pruning later to cut out some dead wood but it’s far better than throwing out a live plant.
Side note:
There are several products that help prevent winter kill. They’re called “anti-desiccants,” a kind of a sunscreen for plants. Spraying an anti-desiccant places a harmless transparent wax coating over the broadleaves. The effect is to reduce the dehydration caused by wind and sun. Typically it’s applied after the first really cold nigh in late November or December. At Mahoney’s we recommend Wilt Stop by Bonide, but there are other good products to choose from.
Winter Moth Alert
Winter Moth Damage: Example of damage caused by Winter Moth
Tree buds are a welcome sign of spring. Unfortunately, spring also signals the return of the dreaded winter moth. In Massachusetts, the Eastern part of the state typically sees the most damage. If not treated properly, and soon, emerging leaves could be riddled with holes, and complete defoliation may ultimately kill maple, oak, apples, cherry, linden and ash trees in as little as four-years. Many outbreaks popped-up last spring, causing concern for this spring. Additionally, the high amount of winter moths we saw this winter is an early warning sign that outbreaks may be high.
Winter Moth Damage: A winter moth caterpillar eating, an already, partially consumed leaf. Research has indicated that tree mortality is likely in as little as four consecutive years of defoliation.
When temperatures begin to average 55°F, the winter moth eggs begin to hatch. The newly hatched caterpillars, resembling an inch worm with a white “racing stripe” down the side, wiggle their way under the scales of flower and leaf buds to feed on the unopened bud. As the caterpillars grow, they continue to feed on unfolding leaves and are capable of defoliation on a large scale. If spring flowering is delayed, the problem is further intensified as caterpillars continue to feed on closed buds. In fruit trees, such as apple or blueberry, this may lead to a loss of fruiting.
Fortunately, there are treatments that are not only effective, but if handled properly, environmentally friendly. The first level of defense is to spray trees now with horticultural oil, such as Bonide All Seasons Horticultural Oil. This spray smothers the eggs while the trees are still dormant (no leaves out). Make sure to apply when temperatures are above freezing for 48 hours, so as not damage the plants. Cover as much bark and stems as can safely be reached. This method will dramatically lower populations; however additional treatments may be needed as some eggs may be protected by bark or lichens on the tree.
Winter Moth Solutions: All Seasons Horticultural oil (left) and Captain Jack’s Deadbug Brew (right) by Bonide
As leaves unfold, caterpillars will appear to swing from the trees on silky strands spreading to neighboring trees. At that time a foliar insecticide containing spinosad, (Bonide’s Captain Jack’s Dead Bug Brew) should be applied. Spinosad is a natural bacterium that targets caterpillars and similar insects. Once ingested, the caterpillars will stop feeding immediately and die within two-to-three days. If trees are sprayed as the leaves are unfolding an additional application will protect the untreated foliage.
Bonide All Seasons Horticultural Oil and Captain Jack’s Dead Bug Brew are available at all Mahoney’s, and most homeowners can handle spraying their smaller trees*. Larger trees are too hard to reach and require proper equipment. Mahoney’s SafeLawns and Landscapes offer spraying services capable of reaching the tops of large trees, as well as smaller. We can also protect against another destructive invasive insect, the Hemlock Wooly Adelgid, For more information or to schedule an appointment call (781) 305-5555.
* As always read and follow label instructions. Additionally, when spraying fruit trees, take care to protect foraging bees by spraying early in the morning or late in the afternoon when the bees are less active.
Christmas Trees 2010: Abnormal Dropping Needles Explained
If you happened to notice an unusual amount of needles dropping off your Christmas tree this past year, you’re not alone. We had several calls about trees defoliating prematurely. Typically we do not get any complaints because we cut our trees very late in the season, specifically to ensure a fresh, long-lasting tree. When we researched the problem we discovered the needle drop related exclusively to Christmas trees raised and harvested in Nova Scotia – not just the trees that we grow at Mahoney’s Tree Farm, but all Nova Scotia trees. So we contacted the Nova Scotia Christmas Tree Association to learn why. Here is their response:
Dear Mahoney’s,
I am so sorry to hear that Nova Scotia trees gave you shed problems in 2010. Overall, it was a tough year as it was extremely warm and wet. Most people think wet weather is good for cut Christmas trees, but it is not, as wet weather means high humidity. This causes needle stomates (the breathing pores) to open up, allowing water to more readily exit the trees. Further, it was an abnormally warm year, and tree metabolism is higher as the temperatures are higher, meaning that the rate of respiration and subsequent moisture loss is even higher. The cut trees cannot replace this moisture on their own. Long story short – it was an especially tough year because it was warm and wet. Cool and dry is actually better.
Sincerely,
Matt Wright
Executive Director
Christmas Tree Council of Nova Scotia
We’d like to add our apology to anyone who experienced a prematurely dry Christmas tree. We pride ourselves in the freshness of our late-cut Christmas trees and will continue to work with the Nova Scotia Tree Council to ensure that when you buy a Christmas tree from Mahoney’s it is the longest lasting tree available. Best wishes for the New Year.
Bill Heptig, Tree & Shrub Manager, Mahoney’s Garden Centers
The last color- Rhododendron mucronulatum 'Cornell Pink'
The last bit of color in the garden coincides nicely with the Thanksgiving Day holiday. The landscape is turning shades of gray and brown as the leaves litter the ground and the bare tree branches form outlines against the sky. There is one shrub, the Korean rhododendron, which brightens the back corner of the garden and has been a reliable bit of late color for the past six years. It is worth noting because it’s the very last of the shrubs in the border to lose its leaves and also the first of my flowering shrubs to bloom in the spring. The leaves finally drop anywhere from the last week of November to the second week of December, depending on the weather. The picture above was taken in 2007 when the grouping of three shrubs was considerably smaller.
They were a bit more orange that year. The color ranges from this brilliance to a slightly more subdued yellow orange, as it is this year. 
This is a deciduous (leaf-dropping) rhododendron and the ‘Cornell Pink’ cultivar was developed at Cornell University in the early 1950’s. The R. mucronulatum was introduced to the U. S. market in the late 1800’s and originates inKorea, Manchuria and Northern China. It will grow up to ten feet tall with a similar spread. I find the flower color of ‘Cornell Pink’ much more desirable than the straight species color, which is a light purple.
The Korean rhododendron buds start to crack color in early April and the flowers emerge towards the end of the month. It will bloom for a considerable length of time and it looks wonderful in front of the blooms of a star magnolia (Magnolia stellata). During the summer, this shrub contributes medium fine foliage and airy grace to the shrub border. The Korean rhododendron fits into a naturalistic landscape quite well and it is working overtime right now in the garden, where it shows up quite nicely from a distance.
I highly recommend adding a few of these to your garden if they are not already in residence. Is there anything in your garden which is still showing color or life? Share if you will. The winter will be long enough.
Evergreens that Survived the Blizzards of 2010
Last winter was the snowiest on record in the Mid-Atlantic region, with three blizzards hitting us in quick succession and accumulations reaching our waistlines - waistlines that, for us gardeners, were expanding from lack of gardening. And after it was all over, tree companies were booked for months taking out fallen and damaged trees, mainly evergreens, that just couldn’t handle that much white stuff. But on my property? Not a single branch was broken, much less a whole tree, and I had to resist the urge to run around and kiss every one of these tough-as-nails plants in gratitude.
Instead, I’ll just show them off right here, starting with the Cryptomeria (Japanese cedar) on the left and Deodar cedar* on the right.
Below, part of a whole hedge of Cherry Laurel (Prunus laurocerasus) ‘Schip’. I also grow the shorter ‘Otto Luyken’ laurels. On the right is one of my five ‘Green Giant’ Arborvitaes. ‘Green Giants’ grow 3-5 feet a year for the first few years, then slow down, so they’re very popular for fast screening.
Next, my ‘English Roseum’ rhododendrons survived the winter and bloomed particularly well this spring.
And this sweet dwarf white pine ‘Blue Shag’ was on the pricey side and I might have uttered a curse or two if it had been damanged by snow.
Oh, but there’s more!
Because I’m such a fan of evergreens, we’re not done yet. More plants that survived the winter happily in my garden include Boxwoods, Pieris japonica, ‘Gold Coast’ Juniper, a Dwarf Hinoki Cypress now 12 feet tall, and some ‘Heleri’ hollies. And to all I say “Thank you and keep up the good work!”
*About cold-hardiness in Eastern Massachusetts, the Deodar cedar is listed by various sources as hardy to Zone 6 or 7. So it’s okay on the Cape but probably not in the Boston area.
Solutions for your Underblooming Endless Summer Hydrangeas
Have you been disappointed by the less-than-awesome blooming of your Endless Summer hydrangeas? The growers of this popular new hydrangea have heard complaints from 
northern gardeners about weak flowering and have responded with some great tips, which Mahoney’s is happy to pass along to our customers. You can also click here for videos about choosing the right one, pruning, potting, uncovering them in spring, and more.
Take it away, Endless Summer experts.
Although a number of factors may contribute to the consistency or inconsistency of blooms, there is no simple answer to this matter. Here are some steps consumers in cooler northern climates can take to help ensure beautiful blooms.
1. Location
Location, location, location! Yes, that old saying is true. In Northern climates, the location of your hydrangea in the garden will have the largest impact on bloom production. The farther north you are, the more sun your plants can tolerate. In zones 4-5a we recommend planting your Hydrangeas in a location that enables them to receive at least 6 hours of sun with some dappled shade in the afternoon.
2. Pruning
Don’t treat your Endless Summer Hydrangeas like an Annabelle Hydrangea by cutting them back in the fall or early spring. By cutting to the ground or within a few inches of the ground, most if not all of the buds on old wood are being removed. In addition, the old blooms of Endless Summer add to the winter interest of your garden. Endless Summer Hydrangeas certainly do bloom on new wood, but it may take longer for flower buds to develop on the new growth of a young plant.
3. Winter Cover
Protection for plants in the first few years is important, as is protection from spring freezes. Since Hydrangea buds emerge early in spring, late freezes may damage bud 
development as well as any new growth. Keeping the crown of plants covered with mulch through May helps protect these buds and any soft new growth from late spring freezes.
4. Feeding your plant
Fertilization is also an important factor in flower production of Hydrangeas. A good quality, slow-release fertilizer applied once in spring or early summer should suffice for all but the most demanding locations. Look for an NPK ratio of 10-30-10. Container plants may need an additional application of liquid fertilizer during the growing season. Remember, if you over-feed your Hydrangeas, the effect is more dark green leaf production with fewer flower buds. In the North (zone 4) we recommend no fertilization after August 15th, as plants need to slow down and acclimate for winter.
5. Watering
The amount you water is one more factor you can regulate to ensure beautiful blooms. Although Hydrangeas are named after “Hydra”, Greek for water, your hydrangeas will form large leaves, lots of green growth and few flower buds if over- watered. Over-watering may slow the formation of flowers considerably. It’s normal for plants to wilt for a short time in the heat of the day. You’re better off to water well and less often, than giving a little all the time.
By following these simple tips you should see wonderful bloom production on your Endless Summer Collection Hydrangeas for years to come.
Autumn's Small Revelations
October is THE month of glorious color in New England. Mid-October gives us the golden reality of peak foliage in hues of scarlet, tangerine and warm yellow, but this change is progressive and the small, isolated bits of color start to appear in late September if one pays attention to nature. In my garden, the first deciduous plant to show color is the poison ivy that climbs many of the trees in the surrounding woodlands. This year it’s brilliant orange. The changing of the foliage is the most obvious change of the season, but even the foliage begins with just a leaf or a branch or two of color. 
The maples are often the first to show any inclination to change from their robes of summer green to the jewel tones of autumn. The swamp maple (Acer rubrum) above has one brilliant branch of red that’s quite difficult to overlook on the morning walk.
With the coloration of the foliage under way, there are many less obvious, often overlooked plants still fruiting and flowering in the garden. It’s worth taking the time to observe the small wonders nature has to offer. In my garden, the purple beautyberry (Callicarpa japonica) is covered with berries that seem impossibly purple. 
This small shrub could be underplanted with fall crocus (Colchicum autumnale), which would create a petticoat of lavender at the base of the shrub.
( Note to self: Underplant purple beautyberry with colchicums.)
October is also a month for mushrooms. I only wish I could identify the edible treats from the more common poisonous varieties. 
I’ll have to satisfy myself with photographing the many mushrooms that appear after the rain. They force themselves up through the woodland debris, often carrying bits of soil and duff skyward on their caps. I find them all intriquing and each is unique.
Evident this year is Mother Nature’s generousity with acorn production. It’s difficult to walk anywhere without crushing or slipping on the acorns. They’re pinging off the car in the driveway and off the windshield on the roadways. 
Does ample acorn production mean we’ll have a harsh winter with lots of snow? Scientists say that there is no correlation, and I sure hope they’re right.
Has acorn production been as vigorous and plentiful in your garden? What small wonders have you observed in your garden these early days of October?
5 Great Shrubs to Fill up the Garden
I coach all kinds of homeowners in gardening and see two very common situations with the identical solution. Beginners often have a blank slate, so where do they start? Others have been gardening for a good while and seen improvements, but their gardens still don’t thrill them. Something’s missing and it’s almost always shrubs, especially big, fast-growing ones that will soon create a nice Eastern fullness and presence in the garden. They’ll provide the sense of enclosure that’s essential in an outdoor space the family can enjoy. And they’ll be the perfect backdrop to perennials and annuals that the homeowners may also want to grow (and gardeners definitely will).
Luckily, there are plenty of great shrubs that, in addition to doing all that, will put on quite a show when it’s their turn to bloom. So without further ado, here are some of my favorite flowering shrubs that help make a yard look like a garden. I’ve provided links to my web page for each one, for additional details. Oh, and best time to plant any of them? September-October. The second-best time is spring, as early as possible.
The doublefile viburnum is perhaps the best-looking viburnum of all, of which there are dozens of great ones for the garden. The doublefile is almost as tall as a dogwood and blooms at the same time. It definitely needs supplemental watering in periods of drought but beyond that, just some renewal pruning after it’s a few years old. My method is to remove a third of the stems to the ground after they’ve bloomed, and they respond well to it.
Next, two of the many weigelas filling up my garden. Also easy-care, they have the added feature of growing really fast. I’ve been happy to see more great varieties of weigela available lately – people need more plants like these that are as close to self-sustaining as you’ll find.
Spireas are another group of shrubs that breeders are working with, and we’re seeing amazing new varieties these days - lots of shorter types, and an array of chartreuse-leaved beauties. This is the old-fashioned bridal wreath type doing great work as a foundation plant in front of my house. Even in the winter when the leaves are bare, it has a large woody presence.
Another fast-grower is this oakleaf hydrangea. In addition to the virtues you see here, its exfoliating bark makes it a focal point all winter. Seriously.
And I couldn’t resist showing off one more hydrangea – the later-blooming ‘Tardiva’ that gardeners just don’t use enough. Garden writers are touting its virtues, so we may be seeing more of them soon. They’re larger and more drought-tolerant than the familiar mophead hydrangeas that bloom in pink and blue.
