Thursday, April 03, 2008
Lose the pines, trim the boxwoods
John Arbogast
Landscape consultant John Arbogast answers your questions every Thursday. Send questions about your lawn, garden, plants, or insects to:
Dear John
5102 Greenfield St. SW
Roanoke, Va. 24018
Or send an e-mail. Answers will be given only in this column. Please don't send pictures or samples.
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Q: I want to move three large and mature white pines on my property. The trees are approximately 30 feet high with a caliper measurement of 10 inches or so. What are the risks? Would you advise against it?
A: Don’t do it. It would cost a lot of money. The work would be back-breaking. And they'd probably die anyway.
One major limitation is the physical size and weight of the root ball required to transplant evergreens. A big ball of soil must be dug surrounding the support and feeder roots. Evergreens have many soft feeder roots that are easily cut or broken off if the soil surrounding them is removed and only major support roots are dug out. The necessary digging to form the large root ball would be extremely labor intensive, if not impossible.
The tree species involved is another deciding factor. White pines are usually fast growers and don’t have the high value of a slow-growing, more costly variety. Even if money is not a concern and a hydraulic tree spade on a big truck is employed, it could remove and lift a tree that is no taller than 25 feet.
Without root pruning during prior years to encourage a dense root ball, which I presume you haven't done, a big pine like yours would not survive a move.
Q: Some of my old boxwoods need help. I live in an older home here in Virginia, and I believe that these are English boxwoods. I need to heavily prune those that have grown over a sidewalk. How and when this can be done? Many of the boxwoods have an orange discoloration on their leaves, especially on the edges of leaves. I have noticed this orange look for two years. Does this mean that the plants have a disease or pest and should be sprayed with something?
A: English Boxwoods can be cut back by as much as half in early to mid-spring. Do it before hot weather begins and new growth becomes difficult.
Use a sharp pruning saw or long-handled loppers to cut trunks or big branches just above a leaf or swollen place on the trunk. Your boxwoods will be bare but new shoots should soon emerge from living buds on old wood just below the cut locations at this time of spring. A light clipping of the ends of those new shoots about two to three months after they emerge will eventually promote side branching and full appearance.
Remove dead leaves and other debris that has accumulated within each plant. This helps promote better air circulation around boxwood trunks and is important for plant health.
English boxwoods grow slowly, so it might take two growing seasons before your boxwoods look attractive again. Weekly watering will assist the recovery process and enhance new growth. If your boxwoods are in a row, run a soaker hose beside the plants and hook it up once per week to run for at least two hours.
Look into the inner parts of your boxwoods to see if the orange discoloration is mainly on outer leaves, which can be a sign of an environmental stress, or if discoloration extends down through all the greenery, which could indicate pests or a root problem. Clipping or cutting back greenery will promote new growth and thus correct the discoleration in the short term.
English Boxwoods are susceptible to various root problems, and sometimes mite presence on the leaves. If you find much dead wood in addition to the orange parts, call a local plant expert such as at your local Cooperative Extension Office and arrange for taking in a plant sample for diagnosis before you purchase any pesticide.
