The Elm tree has 45 species including some semi-evergreen trees and a few shrubs. They are native to northern areas and are grown for their attractive foliage. The Elm Tree grows well in well-drained soil in sun or semi-shade. Summer budding is the main method of propagation.
The American White Elm is a gracefully spreading tree from the eastern USA, the species is often multi-stemmed with large V-Shaped trunks and covered with silver bark. The dark green leaves are heavily toothed and turn butter yellow in autumn. It is still widespread in the US. The cultivar “American Liberty” has an upright habit and it shows great resistance to the Dutch Elm disease (DED).
In tests the “Valley Forge” species had good autumn color and has been shown to have the greatest resistance to disease of all the American Elms.
The Dutch Elm tree is broadly columnar with toothed dark green leaves that turn yellow in autumn. Small red flowers are borne in spring, followed by winged fruits. The Dutch elm tree loves full sun and is not resistant to the Dutch elm disease.
The Chinese Elm tree is a spreading tree with glossy dark green leaves which can turn orange-yellow in autumn, but which often persist into winter. The grey-brown bark flakes to reveal the light brown underbark. This species does not appear to be affected by DED.
Other varieties include the Patriot, Siberian Elm, Sapporo Autumn Gold and the Urban Elm tree.
Begin visual inspection at the top of the tree and work downward.
Use The 1/3 and ¼ Rules of Pruning
Never remove more than ¼ of a tree’s crown in a season
Ideally, main side branches should be at least 1/3 smaller than the diameter of the trunk.
For most deciduous (broadleaf) trees, don’t prune up from the bottom any more than 1/3 of the tree’s total height.
Where possible, try to encourage side branches that form angles that are 1/3 off vertical that form “10 o’clock” or “2 o’clock” angles with the trunk.
For most species, the tree should have a single trunk. Identify the best leader and later branches before you begin pruning and remove defective parts before pruning for form.
Don’t worry about protecting pruning cuts. For aesthetics, you may feel better painting large wounds but it doesn’t prevent or reduce decay.
Keep tools sharp. One-hand pruning shears with curved blades work best on young trees.
For high branches use a pole pruner. A major job on a big tree should be done by a professional arborist.
For larger branches, cut outside the branch bark and ridge collar (swollen area). Do not leave a protruding stub. If the limb is too small to have formed a collar cut close.
When simply shortening a small branch, make the cut at a lateral bud or another lateral branch. Favor a bud that will produce a branch that will grow in desired direction (usually outward). The cut should be sharp and clean and made at a slight angle about ¼ inch beyond the bud.
Correct Pruning Cut
Tree watering is a key part of tree care and it is difficult to recommend an exact amount due to the varieties of climates. But a few rules of thumb will help guide you to water your trees properly.
Watering Newly Planted Trees: For new trees, water immediately after you plant a tree.
Watering Trees During First Two Years: During the first couple growing seasons, your newly planted tree is expanding a lot of energy trying to get its roots established in the soil. Especially during the first few summers of your new trees life, it will have a difficult time dealing with heat and drought. You can make this easier by providing water and covering the soil with wood-chip mulch. Deep watering can help speed the root establishment. Deep water consists of keeping the soil moist to a depth that includes all the roots.
How Much Water and When: Not enough water is harmful for the tree but too much water is bad as well. Over-watering is a common tree care mistake. Please note that moist is different than soggy, and you can judge this by feel. A damp soil that dries for a short period will allow adequate oxygen to permeate the soil.
As a rule of thumb your soil should be moist. Usually 30 seconds with a steady stream of water from a garden hose w/ a diffuser nozzle per tree seedlings is sufficient. Mulching is also key in retaining moisture in the soil.
You can check soil moisture by using a garden trowel and inserting it into the ground to a depth of 2”, and then move the blade of the trowel back and forth to create a small narrow trench. Then use your finger to touch the soil. If it is most to the touch, then they do not need water.
Watering Trees After the First Two Years: After your tree has been established in your yard for two years the roots will be established. This will allow your tree to withstand a wider range of water conditions including on its own because it has a proper root structure.
If your area constantly deals with drought you will want to consider trees listed as drought-tolerant. These trees are adapted to sites in their native habitat that regularly experience prolonged dry spells. Although they are native to drought and are more tolerant than others the first few years of life is critical to the survival of the any tree and follow the steps above will help your trees grow.
Some Drought-Tolerant Species Include
Thornless Honeylocust (Zones 3 to 9)
Arizona Cypress (Zones 7 to 9)
Japanese Zelkova (Zones 5 to 8)
Mugo Pine (Zones 3 to 7)
High Soil Moisture-Tolerant Species
On the opposite side of the spectrum if your area deals with a large amount of moisture or wet conditions here are a few trees that will do better in wet conditions.
Swamp White Oak
Baldcypress (Zones 4 to 10)
Shellbark Hickory (Zones 5 to 8)
Red Maple (Zones 3 to 9)
Silver Maple (Zones 3 to 9)
Paper Birch (Zones 2 to 7)
River Birch (Zones 4 to 9)
Weeping Willow (Zones 6 to 8)
How to Prune Young Shade Trees
This illustrated, easy-to-follow guide teaches you how to shape and guide a shade tree when it’s young so that it is tall, straight, and healthy when it’s old. “How to Prune” includes step-by-step drawings showing how proper pruning in the early years of a tree’s life can save money in the long run and result in safer, more beautiful, healthy, easy-to-maintain trees. The guide is easy to browse and shows you why tree paint isn’t necessary, even on large cuts, how to select and care for pruning tools, and more.
The Importance of Mulching
A newly planted tree’s best friend is mulch. It is very important to remember to mulch your tree after you have planted it.
Mulch is a valuable for your trees health and care because
Mulch insulates the soil helping to provide a buffer from heat and cold temperatures.
Mulch retains water helping to keep the roots moist.
Mulch keeps weeds out to help prevent root competition.
Mulch prevents soil compaction.
Mulch reduces lawn mower damage.
Steps to Adding Mulch Around Your Tree
Add mulch to the base of your tree by removing any grass within a 3 to 10 foot area depending on the size of your tree.
Pour natural mulch such as wood chips or bark pieces 2 to 4 inches deep within the circle.
Keep the mulch from touching the trunk of the tree.
Proper tree care begins with selecting the right tree and planting it in the right place. Trees are for a lifetime, so it pays to spend time now making sure that your tree will thrive where you want to plant it.
Wrong Trees, Wrong Places
Planting large trees under utility lines can eventually mean mutilated trees as they grow to maturity. Large evergreens close to the house on the south block warming winter sunlight. No trees on the north side of the house can leave it vulnerable to icy winter winds.
Short, flowering trees don’t clash with overhead utility lines. Large deciduous trees on the southeast, southwest, and west provide cooling shade in the summer, but don’t obstruct the low winter sun. An evergreen windbreak on the north blocks cold winds in winter.
Step 1—The Tree’s Purpose: Start by defining the purpose for your new tree. Common purposes include aesthetics, privacy, shade/energy reduction, windbreak, or street tree. Your end goal will impact the suitability of different trees.
Step 2: Next consider your planting site limitations, things to consider include:
• Hardiness Zone: your location and weather have a tremendous impact on what trees will grow.
• Height and Spread of Mature Trees: Example overhead wires will limit the height of mature tree and you will want to select a shorter tree. The chart below is a great representation of the range of heights of tree species.
• Sun Exposure: The sun exposure in your planting area will greatly affect how your tree grows.
• Soil Conditions: Some trees can grow in only specific types of soil, while others can grow in almost any condition the type of soil. Determining what type of soil you have in your yard will help you find the right tree.
Selecting a Healthy Tree
Good tree care starts with a healthy tree. Follow these tips and learn how to buy a tree.
What to Look for on Your New Tree
Inspecting your tree upon delivery or at the nursery will help your tree provide a lifetime of benefits.
• Bare root tree: Abundant root growth, fiberous and numerous small roots, good color; moist
• Balled and burlapped tree (B&B): Firm soil ball, with trunk securely tied. Do not accept a plant with a broken “ball”. Do not accept a tree with circling roots at the base of the trunk. Always carry B&B plants by the soil ball, not the trunk, stems or branches.
• Container-grown tree (containerized and potted): Avoid trees that are “root-bound” in the can. Roots can circle around the edge of the container may become circling roots. (Cut any circling roots when planting.) Because of this, B&B trees are generally preferred for large trees. Always remove can, basket or pot when planting.
Bare Root Seedlings
• Roots should be moist & fibrous.
• Deciduous seedlings should have roots about equal to stem length. Containerized
• Soil plug should be moist and firm.
• Avoid tall, spindly tops. Well-developed roots are more important. Balled &Burlapped
• Root ball should be firm to the touch, especially near the trunk.
• Root ball should be adequate for the tree’s size. Potted
• Pot should not contain large, circling roots.
• Pruned roots cut cleanly, none wider than a finger.
• Soil & roots joined tightly.
Some Extra Things to Consider When Purchasing Mature Trees
When choosing trees for city plantings along streets and in parks, you will want to trees with fairly substantial caliper (trunk diameter).
• Strong, well-developed leader (or leaders in a multi-leader tree).
• Bright, healthy bark.
• Trunk & limbs free of insect or mechanical injury.
• Branches well-distributed around trunk, considerably smaller caliper than trunk.
• Ideal spacing between branches, at least 8–12″ for most species.
• Good trunk taper.
• Wide-angle crotches for strength.
• Low branches—they are temporary, but help develop taper, promote trunk caliper growth, and prevent sun damage.
Every fall, thousands of Americans head for the woods to see summer extinguished in a blaze of color. In Wisconsin, they celebrate Colorama. In New England, the visitors are called “leaf peepers.” They travel hundreds of miles north for the yellows, the oranges and especially the reds.
University of Wisconsin-Madison scientists have a new theory about why autumn leaves turn scarlet and why the hues are more vibrant some years than others. They say that the red pigments — called anthocyanins — in plants such as maples, oaks, dogwoods and viburnums act like sunscreen.
“The pigments shade sensitive photosynthetic tissue in fall while trees reabsorb nutrients from their leaves,” says horticulturist Bill Hoch. “Trees need to store as many of those nutrients as they can before the leaves drop.”
Co-authors Hoch, Eric Zeldin and Brent McCown lay out their ideas in an article featured on the cover of the journal Tree Physiology. The researchers are members of the Department of Horticulture in the UW-Madison College of Agricultural and Life Sciences.
“The scientific literature contains many different explanations for why trees make anthocyanins in fall,” Hoch says. “Some theories account for the color change in one tree, but not in other species. Other ideas are clearly wrong. For example, the red does not come about because sugars are trapped in leaves and converted to anthocyanins.”
“Light that is too bright can inhibit photosynthesis any time of the year,” Hoch says. But in fall when trees are breaking down and reabsorbing important nutrients from their leaves, their photosynthetic tissues are especially unstable and vulnerable to too much light and other stresses. Yet trees need the energy from photosynthesis to drive the processes that allow them to recapture as many of those nutrients as possible. Just as this process begins, leaves start producing large amounts of anthocyanins near the leaf surface. The Wisconsin scientists argue that the pigments protect the leaves’ dwindling ability to generate energy during this period.
In addition to high light levels, other plant stressors such as near-freezing temperatures, drought and low nutrient levels trigger increased levels of the pigments. The researchers’ theory agrees with the observation that autumn colors are best when the fall features dry weather with bright, sunny days, and cold nights. It also makes sense of observations that the outer leaves of maple trees, for example, are more colorful than shaded leaves inside the canopy and leaves on the north side.
Hoch says their ideas also explain why most of our native maples and oaks in the Midwest and New England turn red, while European species such as the Norway maple do not.
“None of the European counterparts of these North American trees produce high levels of anthocyanins,” Hoch says. “We think it’s because the weather in that part of the world is cloudier and warmer during fall. European species don’t need the protection of these pigments.”
White Birch was once very popular due to its showy white bark. It always attractive., loves the sun and moisture. Remove dead or storm-damaged wood, cutting to the basal collar, whenever necessary. Sow seeds in the fall through winter. Place in the open so that form and bark can be appreciated.
The airy, small-leaved birch, with its slender trunk and branches, is a graceful ornament to any garden. Birches are renowned for their peeling silvery white bark: some species have gray, glossy black, or orange-brown bark. Birches have toothy leaves that may have a oval or diamond shape.. They turn yellow in the fall. Plant in mid-fall or early spring in loamy soil. Do not plant birch close to borders or fences because it has a wide-spreading surface roots.