Tag Archive | Trees

Small Trees with Big Fall Color

by Lisa Johnson, horticulture educator for Dane County UW-Extension

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Carpus caroliniana

The color of trees and shrubs this time of year is one of the best things about fall. Maples are often the stars of the show, but some small-scale trees can bring the colorful leaves closer and light up the mid-level of your garden. One native tree hardy to Zone 3 that thrives in partial shade and moist to average soil is musclewood (Carpinus caroliniana). Its fall color ranges from yellow to orange to red orange. It grows 20-30 feet tall. Musclewood, sometimes called blue beech or hornbeam, has interesting sinewy-looking bark (hence the name) and ornamental seedpods. Local Wisconsin nurseryman Mike Yanny of Johnson’s Nursery and JN Plant Selections introduced a lovely variety, Firespire (‘JN Upright’), with a tight, upright growth habit and red-orange fall color.

Amelanchier, or serviceberry, trees are Wisconsin natives, hardy to Zone 4 with a similar range of fall color and height as musclewood. Many cultivars are available and most are multi-stemmed plants. They display best fall color in sun, but tolerate some shade and need a moist to average soil. They sport beautiful clusters of white flowers in spring, bird-attracting fruits in summer and silvery bark and an elegant form in winter.

Eastern fringetree (Chionanthus virginicus) is a native multi-stemmed tree hardy to Zone 4, growing to about 15 feet tall. It prefers full sun to part shade in soils with adequate moisture. Fringetree bears large panicles of confetti-like, white, lightly fragrant flowers in spring, shiny green leaves in summer and a good deep golden fall color.

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Trees and Shrubs

by Sharon Morrisey, horticulture agent in Milwaukee County

Tu-BShevat-tree-planting-by-Canopy-Photos-jpgFall is a great time to plant trees and shrubs. Warm soil encourages root growth and the cool air reduces the demand for water. It is said that the planting is the most important 10 minutes of a tree’s life. Years of scientific study have produced improved techniques, so follow these instructions closely.

  1. Find the root flare first. It’s that place at the base of the trunk where it widens before going into the soil.
  2. Remove soil from the top of the root ball, if necessary, until the flare can be seen.
  3. Measure the depth of the root ball after finding the flare.
  4. Dig the hole no deeper than this, trying not to disturb the dirt at the bottom, so the tree will not settle later and become too deep. Make the hole two to four times wider than the ball and gently sloping.
  5. Cut off the container, if there is one. Cut away the wire basket if it’s a balled-and-burlapped plant.
  6. Gently roll it into the hole without holding it by the trunk. Now, cut away as much burlap as possible without letting the root ball fall apart.
  7. Fill the hole halfway with the same soil that came out of the hole. Do not amend that soil. Otherwise, the roots will stay in that soil, growing around and around, instead of moving out into the surrounding soil.
  8. Do not stomp on the soil. Instead, fill the hole with water and allow it to settle before continuing to fill the hole.
  9. Water again.
  10. Form a rim of soil around the outside edge of the hole to hold the water.
  11. Cover the rim and root ball with 2 inches of shredded bark or wood chips. Do not allow the mulch to touch the trunk or the bark will rot and kill the tree.
  12. On slopes or windy sites, use one or two stakes pounded into the undisturbed soil beyond the root ball. Loosely secure the tree trunk to the stakes using webbing with grommets made especially for this purpose. Do not use wire or rubber hose, since these will damage the bark. The tree should be able to sway back and forth because this actually strengthens the trunk.

 

Black Walnut Conundrum

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Leaves and fruit of Black Walnut

Black walnuts have a long history of cultivation on American farms and, to a lesser extent, in gardens all over the East and Midwest. They are beautiful trees, with upright trunks and wide canopies. They bear delicious (though hard to crack) nuts, and they are very valuable as timber trees — a single straight trunk can be worth thousands of dollars.

Unfortunately, black walnuts are not completely garden-friendly. The extensive surface roots compete with anything planted over them, the thick leaf cover produces dense shade, and all parts of the tree exude a chemical called juglone, which inhibits the growth of a great many plants.

Vegetables in the solanaceous group — tomatoes, peppers, eggplants, and potatoes — seem particularly sensitive to joglone, as are many perennials, including columbines, peonies, and chrysanthemums. Hydrangeas appear to hate juglone. So do rhododendrons and azaleas, lilacs, and lilies. Ditto pines and birches, apples, and blueberries.

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Stately Black Walnut with beautiful over-arching canopy

Because juglone-laden feeder roots extend far beyond the tree’s canopy, and juglone-containing leaves and nut hulls also tend to get spread around, none of the plants listed above is likely to do well unless it’s at least 50 feet away from the drip line of a black walnut and 100 or more feet away from the trunk.

So what’s left? Quite a lot, really. Kentucky bluegrass and black raspberries actually seem to thrive when planted near (but not under) black walnuts. If the soil drainage is good and other growing conditions are right, gardeners have also had success with cucurbits (squash, melon, and cucumber), as well as beans, beets, and carrots.

The list of possible flowers is longer, starting with spring-flowering bulbs (except crocus) and woodland wildflowers such as Jack-in-the-pulpit, sweet woodruff, and cranesbill. Many hostas appear to be up to the challenge, and asters, day lilies, coralbells, and Siberian iris are also likely bets. Euonymous usually does o.k., and so do Japanese maples, viburnums, redbuds, and hemlocks.

One warning: As the recurrence of words like “seems” and “possible” suggests, these pros and cons are based on observations, not controlled experiments. And to complicate matters further, the amount of juglone in the soil can vary considerably, depending on such factors as soil type, drainage patterns, soil microorganisms, and the age of the tree.

So, if there’s something you’re dying to try under a black walnut, try it. But watch carefully. Affected plants will quickly show signs of stress and should be moved before they start dying, too.

Do You Feed Your Trees?

tree-970850_960_720Here’s a question that tends to divide folks right down the middle. When it comes to the wisdom of feeding trees, expert opinion is sharply — in some cases acrimoniously — divided, but the weight of modern practice is increasingly in favor of the dictum that less is more.

A small amount of fertilizer is fine. It will help compensate for the absence of natural fertility that tends to distinguish lawns (where all the leaf litter gets raked up and there is no understory to speak of) from woodlands (where the trees are nourished by lots of decayed plant material).

Fence_and_tree_lined_lawn_Little_Laver_Road,_Essex_EnglandBut before you go out and buy tree food, remember that the small amount needed is likely to be already present as a by-product of fertilizing the lawn. Once you get into adding more than that, it’s likely you will do more harm than good — if you do anything at all. The harm comes because fertilizer pushes the tree into making lots of tender, soft growth. It’s lush, it’s green, it’s very impressive, and it’s also highly vulnerable t insect attacks, climate stress, and the myriad fungus diseases that would be thwarted by tougher tissue.

The doesn’t-do-anything-at-all situation results from putting the food where the tree can’t get at it. Most of a tree’s feeder roots are in the top 10 to 18 inches of soil, and most of them start near the out edge of the canopy (the drip line) and spread outward from there. That means using an injector to put the eats down deep is not going to do much except pollute the groundwater. And spreading the tree’s meal close to its trunk will be just as fruitless.

The bottom line: keep feeding to a minimum unless the tree is in a container where it cannot possibly find nourishment on its own. And if you do use fertilizer on a landscape tree, spread it in a wide band that works out from the drip line.

Recycle Your Christmas Tree

Christmas trees are too often tossed unceremoniously onto the curb right after the holidays. But there’s no reason holiday evergreens can’t be allowed to serve long after the merry-making is over.

For a splash of instant green, cut the branches of pine, fir, spruce, or other needled evergreens and add them to barren window boxes or containers.

You can also use branches to protect dormant plants. A think cover of evergreen limbs helps keep the surface layer of soil moist, and also helps to stabilize soil temperature, reducing the rapid cycles of frost and thaw that can heave perennials and shrubs from the ground and rip their roots.

Christmas greenery also can be used as tracery on trellises and arbors. Held in place with plastic ties or string, cut boughs give plants like climbing roses, and vines like grapes or clematis, a good-looking shield from drying winter winds and sun.

In addition, leftover evergreens are useful for augmenting the natural foliage around a bird feeder or bath. Wild birds like protection and aren’t choosy whether their evergreen screen is living or dead.

There is an art to denuding a Christmas tree, though, and pruning shears or loppers are a must. Heavy gloves make it easier to handle the rough bark and the needles. If you must cut up the tree inside, cover the floor with a plastic sheet to prevent a mess of needles and sap.

Remove the evergreen boughs from gardens and planters when the tips of early spring bloomers, like crocus or snowdrops, have pushed about an inch out of the ground. Where no bulbs are planted, leave the branches until mid-April or whenever spring seems securely in place.

Living Christmas Trees

by Outagamie County Master Gardener Terry Tess

real-potted-christmas-trees-sydneyEach year many people choose to bring a living tree into the home for Christmas. Smaller potted and even some balled and burlapped evergreens make great candidates for a living Christmas tree. Living Christmas trees should only stay in the home for 2-3 weeks and prefer cool room temperatures. They should be “eased in” to the home by holding them in an enclosed porch or garage until ready to be set up in the house and then “eased out” in the same manner when finished. Lighting the tree with cool LED lights is also a big help. Treating the tree with an anti-desiccant spray such as Wilt-Stop will also slow down moisture loss. Water the tree every day as it can never be allowed to dry out. Once the decorations are removed, plan on planting the tree immediately. This means that you need to plan ahead and prepare a planting hole now to receive the tree in January.

7c4cca738d67b1976b24744bf6c62e3aChoose a proper location in your yard to be the final home for your Christmas tree. Take into consideration the ultimate size of the tree as well as its soil and light requirements. Dig the hold before the ground freezes. The size of the hold should be as deep as the root ball and 2-3 times as wide. Amend the soil with leaf compost and store the soil in a location where it will not freeze and be easy to access in January. Now fill the hole with straw to slow down the frost. At planting time remove the straw from the hole and install the tree using the saved soil. Water the plant heavily and mulch around the tree using the same straw that once filled the hole. Plan on watering the tree again in early spring once the soil has thawed.

What a great holiday tradition to begin this year and to remember for many years to come as the trees grow and flourish!

Terry is a Design Build Manager/Horticulturist/Registered Landscape Architect for the Vande Hey Company in Little Chute, Wisconsin.

More trouble for our trees?

by Mary Learman, OCMGA Master Gardener

Did you lose trees to Dutch Elm Disease? How about the Emerald Ash Borer? What we don’t need is another disease that wipes out our trees — especially in the Urban Forest where a very high percentage of the trees planted in most cities may be some form of Maple.

wpr-meiller-weather-plantdiseases-tarspotIf you noticed black spots on the leaves of your Maple this year, you’re not alone. Fortunately, although the black spots are unsightly, they’re probably not a harbinger of yet another disaster-in-the-making for our tree population. However, it is something you should address!

For more information about caring for your Maples, follow this link and read the article by Jill Nadeau of Wisconsin Public Radio.