Care and maintenance of trees and shrubs

As we approach the middle of this year’s growing season, I want to remind you to make sure you continue to thoroughly water any newly planted trees and shrubs, as well as any that you planted a year, or even two years, ago.

I realize that I have been complaining almost every week about how much rain we have had this season, and it is true that we are still way above average in terms of precipitation, but, at this time of year, even a soaking rain event of one or more inches will be gone within a week. Unless you record an inch of rain in any given week, you should give those newly planted trees and shrubs a thorough soaking every week. The rule of thumb is to water this season’s new plantings weekly; those planted last year should be watered every two weeks and even those planted two years ago still will benefit from being watered at least once a month.

Trees and shrubs need to develop a good root system to survive and thrive. In most cases, when a newly planted tree or shrubs fail to survive the winter, it is due to lack of water during the previous growing season. The tree or shrub may appear to be just fine with no evidence of wilting, as you would notice on your annuals or perennials, but the damage may not show up until years later.

This is perhaps the most common reason why woody plants fail to become established in the home landscape. The best way to apply water is to just let it trickle over the root zone by leaving a hose barely trickling at the base of the plant for an hour or so or even longer. Squirting the base of the plant with a hose at high volume for a few minutes does not work, as most of that water simply runs off. Placing a five gallon pail at the base of the tree with a tiny hole drilled in the bottom can also work well, if it takes a half hour or more to drain. Five gallons of water is a minimal amount to apply to a tree or large shrub.

It is also important to maintain a mulched area at the base of the tree or shrub. The wider, the better! No tree or shrub can compete with grass when it comes to absorbing moisture. A two-inch caliper (caliper is the trunk diameter at the base of the tree) tree should have at least a three-foot wide diameter mulched area at its base. The best mulching material is shredded bark or woodchips that is no more than four inches thick. Mulches that are thicker than that may actually suffocate roots. Shallower mulches are OK, but they decompose quickly and must be renewed more often. The mulch should be thinnest right at the trunk and thickest at the perimeter. Thick mulch piled up on the tree trunk may cause the tree to rot at the trunk. Avoid “volcano” mulches!

The mulch not only conserves soil moisture and nutrients, but also provides a buffer zone that prevents the tree from being bumped by lawn mowers, or scarred by weed whackers. Bumping the trunk with a lawn mower or hitting it with a string trimmer may not appear to do any immediate damage, but it does internal damage that may not show up for years.

Restrict any pruning to removing dead or diseased branches or correcting serious structural defects in shade trees, such as narrow crotches or crossing, rubbing, limbs. Pruning creates wounds that trees must expend energy to deal with, and that energy is better used growing roots and leaves. Newly planted fruit trees should also have the fruit removed for the first season at the very least and perhaps the first two seasons, as the process of growing and ripening fruit also drains the tree’s energy.

Remember that you spent lots of money buying these plants, so spend some time ensuring they grow to their full potential!