Even though the calendar tells us we have now officially made it to fall, it's not quite time to put away those gardening tools. There are still quite a few things to do in the garden, including planting trees and shrubs that will establish roots during fall and winter.
I think there is sometimes a misunderstanding about trees and shrubs. People think that just because the above-ground part of the tree is dormant, that the below-ground parts are, too. This couldn't be further from the truth. In fact, trees, shrubs and perennial plants are busy during the fall and winter months (except for when it's really cold) producing new roots so the plant comes back bigger and better next year.
The plant typically pulls nutrients down into the roots at the end of the growing season to store them during winter. Deciduous trees and shrubs break nutrients down in the leaves and re-absorb them before the leaf falls off (this is what leads to fall foliage colors).
Plants typically try to pull as many mobile nutrients into the roots as they can. It could be thought of as a survival mechanism for the plant to regrow from the roots if the above-ground part freezes and dies. It's almost like humans trying to preserve food for the winter by canning, freezing or putting produce in a cellar.
So the roots end up having an extra portion of energy and nutrients. Since the plant isn't expending energy to grow its above-ground portions, the roots can tap into some of that energy for extra growth.
Evergreens also grow roots in the fall and winter since they are also not growing their above-ground parts. They have the added benefit of being able to make more energy since their leaves are still intact.
To take advantage of this, fall is a great time to plant new trees and shrubs. The reduced heat and (usual) increase in rain and moisture also make it easier to establish trees and shrubs without having to water them as much if you planted them in the spring or summer.
Of course, correctly planting those trees and shrubs is key to making sure they are successfully established and live to have long and healthy lives.
Here are some things that are key to properly planting trees and shrubs:
n Test the soil. This is always key for anything you plant. You'll want to adjust the soil pH and nutrients to meet the new plant's needs. It is even more important in the early years.
In West Virginia, you'll most likely have to apply lime to raise the pH, unless you are planting an acid-loving plant like azaleas, blueberries, hollies or rhododendrons.
You can find the information for free soil testing from the WVU Soil Testing Lab at soiltesting.wvu.edu or contact your county WVU Extension office to get a form to send with your sample.
n Assess the planting area for any overhead barriers for trees. If there are power lines or other obstructions overhead, be sure to check the tree/shrub growth height to make sure it won't interfere with the power lines.
Also check sources for the plant's expected width to make sure it won't grow into houses or other structures. Improperly placed trees and shrubs will result in repeated hard pruning that is not good for the plants. Avoid planting in places where such pruning will be necessary.
n Dig the planting hole at least twice as wide as the root mass, but do not dig it deeper than the root mass. Planting too deeply is a major reason many trees and shrubs fail.
When planted, you want to see the root flare where the stem/trunk connects to the roots above the soil level. In some cases, trees and shrubs are planted too deeply in pots, so you may not be planting it as deeply as it is planted in the pot.
Make sure you don't dig the hole too deep - if you do and fill soil back in before planting, the tree could sink in the loosened soil.
n Do not add compost, potting soil, fertilizer, rocks or anything other than the native soil into the hole. Doing so could create a soil interface problem in which roots don't want to grow out of the planting hole into the native soil (which is hard, red clay in most of West Virginia). This could result in roots growing around the planting hole and the death of the tree in several years due to girdling/strangulation.
Many sources even recommend removing all the soil included in pots with the plants to avoid this problem. Build a soil mound in the middle of the planting hole to help spread the roots out.
n Remove any damaged or extra-long roots.
n Plant the tree or shrub with the stem/root interface (root flare) above the soil level. You can create a berm of soil around the edge of the planting hole to help hold water for it to soak down into the root zone.
n Water well, filling in any holes that appear with native soil.
n Mulch the planting hole with about 3 to 4 inches of woodchip mulch to help hold in moisture, making sure to keep the mulch from touching the trunk of the plant.
n Stake the tree only if it seems unsteady. Staking is usually only needed for larger diameter trees (larger than an inch or two) that are tall (top heavy). Staking should only be necessary for a few growing seasons.
n After planting, fertilize around the tree with the fertilizer recommended by the soil test.
n Keep well-watered for the first two years. Check the tree after a year or two. If you can shake it and make the whole tree/roots move when you push, it hasn't been properly planted and established.
Keeping these tips in mind can help you establish healthy trees that can provide years and decades of enjoyment for you, your family and your neighbors.
John Porter is the WVU Extension Service agent for agriculture and natural resources in Kanawha County. Follow him at @WVgardenguru on Facebook and Twitter and online at wvgardenguru.com. Contact him at john.porter@mail.wvu.edu or 304-720-9573.