An old Chinese proverb states, ″The best time to plant a tree was 20 years ago. The second best time is now.″ One way to think about this is that a tree planted 20 years ago would be providing a good amount of shade by now. But it's also a reminder of just how much trees grow over time. This is why it's very important to keep the mature height and spread of trees and shrubs in mind when you're considering choices and locations for planting. Consult the plant tag for information, talk to experienced garden center or nursery staff, or do some research in books or online to find out the expected height, width, and growth rate of a plant before purchasing it. Even though young trees and shrubs may look small and spindly when they're first put in the ground, they will grow! Make sure you're placing them where they will have adequate room to mature. You don't want to have to rely on severe pruning to keep trees and shrubs from damaging foundations, growing up against siding, covering windows, or blocking walks and driveways. Plants will look best and be healthiest when they are allowed to grow freely without being crowded by neighboring plants or immovable structures.
Once you've decided on the location for planting and the best type of plant for that location, you'll want to select the best and largest specimen that will fit your budget. If choosing bare root plants in early spring, select ones that are fully dormant, but have pliable branches, swollen buds, green color beneath the bark, and a full root system with a well-formed network of large and small roots. Avoid plants with dry buds, dying twigs and branches, and damaged or withered roots. Plants in containers or with balled and burlapped (B&B) rootballs should look healthy. The container or rootball should be large enough to provide an adequate root system for the amount of top growth. Branches and trunks should be relatively damage free.
Always handle plants from the bottom; never by the main stem or branches. If plants are in leaf, protect the leaves from wind damage on the trip home. If you're transporting plants in an open truck bed, wrap the crown of the plant with plastic or burlap for protection. (And if you get trees and shrubs delivered from a garden center or nursery, make sure the plants are similarly protected and handled properly during delivery.)
Dig the planting hole at least two to three times wider than the width of the rootball; as much as five times wider if you're planting in heavy or compacted soil. To determine how deep to dig the planting hole, start by examining your tree to locate the trunk flare -- the point at the base of the trunk where it begins to flare out and meet the topmost roots. On some plants, the trunk flare will be visible at the top of the rootball. But sometimes the trunk flare gets covered with soil when a B&B rootball is dug or a container plant is repotted, and you'll need to remove that extra soil to expose the trunk flare before planting to avoid ending up with a tree that is planted too deep. (It will be easy to see the trunk flare on a bareroot tree as both the trunk and roots are exposed to view.)
Measure the distance from the trunk flare to the bottom of the rootball and dig the planting hole to that depth. This ensures that the trunk flare will end up right at the soil surface when the tree is planted. Correct planting depth is crucial to the long-term health of the tree; planting too deep can cause poor root system development and lead to girdling roots that can kill a tree years after planting. If you're planting in heavy clay soil, make the hole slightly shallower so the trunk flare sits a couple of inches above grade. Then taper the soil out from the trunk to about 2 feet away from the trunk in all directions to keep excess water from accumulating around the base of the plant.
You won't see a noticeable trunk flare on multi-stemmed shrubs, but correct planting depth is just as important. Plant these with the top of the rootball at or slightly above the soil line. But examine plants carefully before planting to see if there appears to be too much soil at the top of the rootball and remove any extra if necessary.
For bare root plants, remove any damaged roots. If few new feeder roots are visible prune an inch or two off of each healthy root to encourage more rooting. Soak the roots in a bucket of water for as long as possible, but no more than 24 hours, as you prepare the hole. Mound the soil at the bottom of the hole and spread the roots around the mound.
For container grown plants, carefully remove the plant and place it in the hole, disturbing the root ball as little as possible. If the roots are circling around the rootball, use a sharp knife to slice vertically into the rootball an inch or two deep in three or four spots around the sides of the root ball and in an X across the bottom of the rootball. If the plant is in a biodegradable, plantable container, remove the top portion of the container so that it doesn't protrude above the soil line.
For B&B plants, after the plant is placed in the hole remove any twine around the ball and cut away at least the top third of any untreated burlap surrounding the rootball. Make sure none of the burlap is visible above ground. If the burlap is synthetic or treated rather than natural, all of it must all be carefully removed. If the rootball is also enclosed in a wire basket, cut away at least the top third of the wire basket; even more if you can remove it without the rootball falling apart.
Use the same soil that you took out of the hole when you dug it to backfill around the plant's roots. Don't add compost, peat moss, or other amendments to the soil. This can hamper the establishment of your tree or shrub by discouraging roots from growing out into the surrounding soil, which they need to do for the plants to thrive in the long run. The exception is when you are planting shrubs in a bed large enough to contain their roots as they mature, as long as you amend the soil in the entire bed. In either case, don't add fertilizer at planting time as it can harm newly developing roots.
Water the plant thoroughly and keep it watered regularly throughout the two growing seasons as it gets established. But don't overwater; soggy soil is as bad for plant roots as drought. Let top few inches of soil get almost dry before rewatering; then water deeply enough to soak the entire depth of the rootball.
Unless you are planting in an extremely windy location, on a slope, or the rootball is crumbling, it is best not to stake trees with a trunk diameter of less than 2 inches. Some swaying in light winds helps strengthen the trunk and encourages a stronger root system. If you do stake your tree, remove the stakes as soon as the tree is established, usually after one season of growth.
Get your trees and shrubs off to a good start and you'll enjoy the fruits of your labors for many years to come.
Steve Trusty has a degree in horticulture from Iowa State University. He has been helping gardeners receive more enjoyment from their lawns and gardens for years through radio, TV, books, magazines and websites.