Читать книгу Landscaping with Trees in the Midwest - Scott A. Zanon - Страница 15

Tree Cultural Practices

Planting

THERE ARE TWO ideal times to plant trees: fall is the best season; early spring is a good alternative time. However, planting the correct way can make the difference as to whether a plant survives its crucial first year. How the plant is packaged influences the condition of its roots; that, in turn, determines how to put the tree in the ground to thrive.

There are three types of plant packaging: bare-root, container-grown, and balled-and-burlapped (B&B).

Bare Root

Most mail-order catalogs ship purchased plants in bare-root form. These are harvested from fields with no soil attached to the roots. These plants are very perishable and should be both purchased and planted prior to spring budbreak. The advantage of bare-root plants is that they allow a thorough inspection of the root system prior to planting.

After taking possession of the plant, one must keep a bare-root plant damp, being careful not to allow its roots to dry out prior to planting. Even though it is in a dormant state, the plant is alive and requires water to survive. Keep it out of direct sunlight, too.

Prior to planting, carefully inspect and prune the roots. With pruners, remove all damaged and/ or turned-in roots. Keep your pruning blades sharp: clean cuts heal faster and decrease the chances of disease.

Dig a hole wide enough to allow roots to spread into their natural position. It must also be deep enough so the crown of the tree will be at or just above the soil line. Break up any soil clods to prevent air pockets and backfill half of the hole. Slowly water to settle the soil around the roots. Continue to backfill the hole, then water again to settle the remainder of the soil. At this point, many people use their feet to tamp the soil. All that really does is promote compaction; it should be avoided. Be sure to keep the soil around these plants moist as bare-root plants will initially require more frequent watering than those container-grown or balled-and-burlapped.

Container Grown

The most popular option for consumers is container-grown plants. These plants are grown above the ground in a pot, filled not with real soil but with an artificial medium, leading to much easier handling.

Regardless of the material, remove and discard the container prior to planting. Inspect the roots. Gently loosen (but do not remove) the whitish-colored roots from the surface of the soil ball. This allows expansion of the roots into the new soil site and is imperative for the tree’s survival.

Again using sharp pruners, cut out the woody, thick roots to prevent them girdling the trunk. The flow of water and food is greatly decreased throughout the plant if girdling occurs. If the plant is root bound, use a sharp knife to slice it from top to bottom in three to four spots, being careful to make the cuts two to three inches deep. In a healthy plant, new roots will sprout from these cuts.

Dig a hole two to three times wider than the width of the container; this allows emerging roots to expand horizontally into the loose soil. Allow the crown of the tree to be slightly above grade level. Set the plant, backfill halfway, then water to settle the soil. Finish backfilling and water again to settle the rest of the soil. Do not tamp the soil as it will promote compaction.

B&B

Larger trees and shrubs typically are sold balled and burlapped (B&B). B&B plants are field dug, with a ball of soil wrapped in burlap surrounding the roots. These plants are mainly available at nurseries as their weight makes them difficult to ship and cumbersome to work with. That being said, larger plants are often only available in this form.

Dig a hole two to three times wider than the root ball; this allows emerging roots to expand horizontally into the loose soil near the soil surface where more oxygen is present. Make sure the root-ball top sits just above the soil grade.

After the plant is placed properly in the hole, backfill halfway and water to reduce air pocket development. This will also assist in stabilizing the plant. Contrary to popular belief, remove all wire or rope tied around the main trunk and remove the burlap from the top of the root ball. The burlap on the bottom of the root ball will decompose and disintegrate as the roots grow through it and expand.

Backfill and attempt to break up large clods of soil preventing air pockets. Construct a raised berm around the outside planting hole. Do not place extra soil on top of the root ball. Gently water inside of the berm allowing the soil to settle around the root ball. Once again, do not use your feet to tamp the area.

Watering

One inch of water per week during the first year is a good guide. In our northern climate, irrigate until the ground freezes. During dry periods, water established trees every 10 to 14 days.

Mycorrhizal Fungi

This soil treatment (supplement) for trees is a standard part of reforestry practices in most areas of the world and has been around since the 1850s. Coexisting with trees and plants in nature, these beneficial fungi provide a safety net for the tree in times of stress. By colonizing the roots and extending themselves further into the soil, the fungi enable the tree to absorb more nutrients and moisture, resulting in a healthier tree better capable of tolerating stressful conditions.

Fertilizing

New plantings should not be fertilized during the first year. For established plants, in the early spring use a complete fertilizer at a rate of two pounds per one inch of trunk diameter. Apply a second application at the same rate in late summer. An easy and effective way to apply the granular fertilizer is with a broadcast spreader.

Mulching

A layer of mulch, three to four inches deep, around newly planted or established trees helps maintain soil moisture, smothers weeds, regulates temperature, and protects from the dreaded trimmer or lawnmower trunk damage (lawn mower blight).

Pruning

Inspect your new planting and remove any broken, dead, or diseased limbs. Wait one to two years before beginning to train and shape. Use selective pruning for established trees as needed to maintain size, shape, and to encourage growth, flowering, and fruiting. Most plants respond favorably to late winter or early spring pruning. It is also easier to see what needs to be pruned when leaves are absent. Remember, though, to prune spring-blooming plants right after they flower, not before, or no flowers will exist.

Staking

Proper staking is done to prevent the root ball from rocking; it is not intended to prevent the top of the tree from being blown about by the wind. A stable root ball is necessary for good root development. But almost all staking should be removed after one year; many times staking is not even warranted.