October 2019 Horticulture News
Fall is for Planting
A gardener’s biggest challenge when planting trees and shrubs in this part of North Carolina is the soil. Most often plants suffer from improper soil preparation and planting techniques. A properly planted tree or shrub will be more tolerant of adverse conditions and require less management than one planted improperly. I often see trees and shrubs planted in compacted soil with a hole just big enough for the plant’s root-ball to fit in. This sets the plant up for failure immediately. Let’s look at some ways to improve planting techniques and survival rates of plants.
When you buy plants, you have a choice of purchasing bare-root, balled-and-burlapped, or containerized plants. Most often containerized plants are the easiest to handle and they also have 100 percent of their roots still attached. However, one problem of container plants is they may have become root-bound. When you buy a root-bound plant, before planting, cut down the sides of the root-ball so new, fibrous roots will grow and spread out as the plant grows. You can also purchase plants that were grown in a bag. Treat them the same way you would a plant in a container.
Bare-root plants tend to be slightly cheaper, however you can only plant them when they are completely dormant. Larger bare-root plants usually require staking as well. Larger shrubs and trees are usually harvested as ball-and-burlapped plants from a field. The main disadvantage of B&B material is that 90 to 95 percent of the roots will be severed at harvest time. The best time to dig and replant B&B material is when the transpiration demand is low and root generation potential is high, such as fall, winter, and early spring. Transpiration is the process of plants releasing water vapor through leaves. Research shows that it takes as long as 2 months for new roots to be initiated from the callus formed after a root was severed. It can be as long as 3 months before the regenerated roots absorb moisture outside the root ball. Most studies indicate that the period of reduced vigor following transplanting will last about one year per each inch of trunk caliper. It will take a 3-inch caliper transplanted tree three years to regain an original root:shoot ratio.
The size of the plant you buy is your decision. Small plants tend to become established faster and they are more economical. Many consumers, however, want the “instant” landscape look that is accomplished by planting larger plants. Keep in mind that these large trees and shrubs may achieve the instantaneous effect, but post-transplanted stress and costs increase with the size of the tree.
In many areas, gardeners will find that the soils are compacted and sometimes poorly drained. In this situation, the best thing to do to create a good root-zone is to till the bed as deep as you can and amend the bed with a topsoil or soil conditioner mix. Soil conditioners could include composted pine bark, compost, etc. If you cannot amend the bed and you are planting only one shrub or tree make sure you dig a wide hole, 2 times the size of the root-ball. If the soil is poorly drained then plant the shrub or tree with 1/4 of the root-ball above the ground and mulch. It is better for plants to be slightly raised instead of planted too deep because roots can suffocate and drown. Any backfill used around the plant should be the original soil.
You would like to avoid the “bathtub effect.” If you backfill with a porous material instead of the existing soil, a puddle will form under the plant. The puddle under the plant will remain there until it drains into the existing soil underneath-the-plant. This can lead to root-rot problems and eventually death of the plant. This happens very often in many landscape plantings throughout Franklin and Wake County due to compacted soils from heavy construction equipment. If you do have a wet site then make sure you select plants that can tolerate “wet feet.”
Sometimes, a newly planted tree or shrub will need additional support, anchorage or protection. If a tree is staked, then the stakes should be removed after one year to keep the rope or wire from damaging the trunk of the plant or girdling the plant. The last thing to do after planting is to mulch around the plant to prevent weeds and to keep the soil moist and cool. The mulched area should include as much of the root zone as possible. For individual plants such as trees, the mulched area should extend at least 3 to 6 feet out from the base of the plant. It is advisable to pull the mulch 1 to 2 inches from the base of plants to prevent bark decay. Mulch depth should be between 3-4 inches.
Fall Turf Pest: Fall armyworms are approximately 1-1½ inches long, depending on instar, and can vary in color from a green to mottled brown, to almost black. Fall armyworms have wide black stripe running down each lateral (side) of the body.
Always a Fall Favorite: Argiope aurantia is a showy spider usually noticed in late summer. It has several common names: black-and-yellow argiope, black and yellow garden spider, corn spider, golden garden spider; golden orb-weaver, writing spider, yellow garden argiope, yellow garden orb-weaver, and zipper spider.
Meet the Muscadine: Muscadine grapes are a southern specialty. Native to North Carolina, the deep purple and bronze-toned fruit clusters adorn farms, fields and gardens throughout the southeastern United States.