TREES AND SHRUBS
WATERING:
The greatest cause of plant loss is due to improper watering. Both watering too much, or too little, can be injurious or kill new plants. Plants require at least an inch of water a week during the growing season, and if there is not enough rainfall that week, then the plants will need supplemental watering. Plants do better with a thorough soaking, keeping the roots deep, rather than light sprinkling that causes the roots to come to the surface in search of more water. Thorough soakings once every two weeks is generally sufficient. A rain gauge can be used to monitor how much water your new garden is actually getting. An easy method is to run the water at 1/4 to 1/2 flow and water the base of the plant. Let it trickle over the root zone until it no longer takes in water and move to the next plant. Repeat this process once more, to make sure the new plants have sufficient water. This only needs to be until the plants have established (usually 8-12 weeks if the weather is good).
In Southern Wisconsin, soil types vary considerably. In heavy clay soil found in Milwaukee and Mequon, or during wet, cool weather, don’t water as often. About half as much is sufficient. In sandy, rocky soil or very hot weather, water about twice as often, but remember it must be deep! Water close to the base of the plant so the bottom of the ball gets wet. Too much or too little watering can cause wilting. If you are not sure, dig down near the root ball 3-6” for shrubs and trees to determine if the soil is too wet or dry.
Evergreens have special watering requirements. In the winter, evergreens can dehydrate when the roots can’t take up water from the frozen ground. If it was a dry summer or fall, soak the area with up to an inch of water around the evergreens before the ground freezes hard, so the plants have enough moisture to make it through the season. This should be done around Thanksgiving, It seems hard to believe, but Wisconsin is like a desert in the winter, it is VERY hard for evergreens to get water when the ground is frozen.
FERTILIZING:
Generally, fertilizing can be done three weeks after the planting with soluble fertilizer. However, a slow release tablet was placed in the planting hole at the time of planting. Do not get fertilizer on the leaves as it can burn them. Follow directions VERY CAREFULLY. Too much fertilizer can kill the plants; a diluted application the first time may be desirable. Miracid Liquid Fertilizer is very good for evergreen trees and shrubs, including boxwood and azaleas, and June is a great time to apply it. If the lawn is regularly fertilized, the trees in the lawn will get ample nutrients. To prevent soft growth that can freeze, stop fertilizing after August 15th.
WINTER PROTECTION:
There are two concerns for the winter: rabbits and other animals, and sunburn. To prevent animal damage, place a hardware cloth (galvanized mesh) around the stem (to the top or at least 30”) and then twist tie the ends together. This is a service Wandsnider can provide. Bury the bottom of the cloth with at least two inches of soil. White paper or white plastic spirals can help prevent sunburn on smooth barked trees, but MUST be removed the following April.
PROBLEMS:
Quite often what appears to be a problem is actually the plant’s way of protecting itself. Leaves are replaced yearly, and the plant may lose up to half its leaves and small branches after transplanting. Remember that the tree or shrub has lost some root mass in being moved and may self prune to compensate until it can support a new crown. In the meantime, roots are being produced. This may take up to three years for a larger plant, and then it will take off. The loss of leaves should become less severe within a few weeks of being transplanted. This can also happen to evergreens, after several weeks, this will also stop. If the foliage is wilting or droopy, it is probably dry, so check for water. If the foliage is yellowing, and the margins are getting brown, it is getting too much water! If branches are actually dead, just prune them off. Plants may respond differently even if they are the same species. Plants are individuals and may not adapt to new conditions as quickly as other plants in the same garden.
PERENNIAL PLANTINGS
By definition, perennials return each year. They grow and require dividing and pruning. By removing dead leaves and spent flowers the plant often rejuvenates, and will extend its bloom time. This also keeps unwanted new seedlings from sprouting. New seedlings are seldom as nice as the parent plant, and can become weedy and out of control. Spring flowering plants can be cut back by half after flowering, and fall flowering plants can be cut back to the green foliage at the base of the plant. Plants should be divided when the clumps get too big for the area, the flowers are getting smaller, or the plants open up in the center. Dividing is easily done with a shovel with a sharp edge or a knife, and will increase the vigor and blooming ability of the plants.
WATERING:
Perennials require deep watering (down through the top 5-6 inches of soil) to keep the roots deep. The plants will do best by watering the ground, not the leaves. Wet leaves can lead to diseases, and poor watering techniques will cause the plants to become shallow-rooted and prone to wilt. Water when the top layer of the soil is dry (one to two inches) and no rain is predicted. Don’t water overhead in the evening, when wet leaves are vulnerable to fungal invasion. A soaker hose is preferable rather than a sprinkler.
FERTILIZING:
A granular or liquid 10-10-10 (balanced nitrogen, phosphorous, potassium) fertilizer is all that is necessary to keep the plants lush and growing. Apply according to package directions, unless a fertilizer with or without a pre-emergent herbicide was already put down on the garden when it was planted.