Spring and Autumn: Time to Plant Trees & Shrubs
In most parts of North America, early spring, while deciduous trees are still leafless and dormant, is the best time to plant. Autumn or winter planting is recommended in areas where summers are extreme and winters are mild, such as parts of the South and West.
- Spring is the only time you should plant bare-root trees in northern climates.
- Balled and burlapped trees should be dug from nurseries in early spring and can be planted in yards in spring or early summer.
- Container-grown trees can be planted successfully almost any time of the year, except when the ground is frozen.
- There are a few exceptions. Trees with active, late-winter sap flow, such as birch and sugar maple, should be planted after their sap flow ends, just as the leaf buds begin to unfold.
- Fleshy-root trees such as magnolias should be planted after their leaves have expanded slightly.
- Evergreens are best planted in early autumn, after summer heat is gone but early enough to get established before winter sets in.
- Although you can plant trees and shrubs almost any time the ground can be worked with a spade, avoid planting in late spring, right before hot summer weather, and in very late fall, because roots may not have enough time to get established before winter weather.
Spring, Summer, and Autumn: No Staking Necessary
Although you may see some staked trees, in general you should avoid staking.
Here’s why:
- Trees need to move and bend with the wind to develop strength. When they are staked, they do not develop strong trunks from the stake on down. They also are more subject to breakage from wind because the entire tree is not allowed to move as much. Rubbing and girdling from stakes and ties can affect the trunk as well, creating wounds that are susceptible to attacks from diseases or pests. The tree may also grow too fast with an underdeveloped root system.
- There are a few exceptions. Bare-root and large balled and burlapped trees may not be able to support themselves at first, especially in windy settings. After planting, watch the tree to see if it tips or leans; if so, it may need temporary anchor staking.
- Each tree needs at least three stakes. Broad, soft tie materials (such as nylon stockings or elastic webbing) are fastened from the tree to the stake. Avoid using wire, string, or other materials that can cut into the trunk.
- Remove the stakes as soon as possible. Research shows that almost all trees staked for more than two years have a higher probability for breakage.
Spring, Summer, and Autumn: Watering
During the first year after planting, water is the most important element in tree and shrub survival. Always water deeply and thoroughly, even if less frequently; avoid frequent, shallow watering, as the roots will travel to the surface to receive the water and won’t establish themselves deeper.
- Water during the growing season during periods of drought, particularly the first year or two while the plants are getting established.
- Place a hose at the base of the tree and allow a slow trickle of water to flow for at least 5 minutes. Shrubs can be watered for less time. If you have sandy soil, water more frequently; if you have heavy, clay soil, allow more time between waterings.
- Autumn is the most important time to water trees and shrubs, especially evergreens. Water well before freeze up. Moisture is crucial to the survival of plants over the winter; when we experience a dry season, the success of your plantings will rely on the additional provision of water to reduce the occurrence of winter burn and die back.
- For evergreens, the application of an anti-desiccant such as Wilt Pruf is a beneficial practice to aid in the reduction of moisture loss. Applied before temperatures drop below freezing, Wilt Pruf acts as a coating on the needles and foliage, sealing in the moisture for the winter.
Spring, Summer, and Autumn: Fertilizing
Good news: Fertilizing is one thing you probably don’t need to do! Most soils have enough nutrients to grow trees and shrubs. Only fertilize for specific elements when a soil test indicates nutrients are missing.
Spring, Summer, and Autumn: Mulching
- A 2” deep ring of mulch that extends to the drip line of a tree (the reach of the branches) is a great way to conserve moisture and suppress weeds that compete with tree roots for water and nutrients. Keeping the depth of the mulch at 2” or less will avoid trapping too much moisture, which can kill roots. Also avoid direct contact with the trunk or crown.
- DO NOT create mulch “volcanoes” – where mulch is placed in a cone shape directly against the trunk of a newly planted tree. Too much mulch directly against the bark causes rot, circling roots, and disease problems.
- Organic mulches such as shredded pine decompose, adding nutrients to the soil.
- Mulch is also helpful in keeping lawn mowers and other equipment away from trunks.
Autumn and Winter: Wrapping
- Tree wrapping in winter months protects against sunscald, not cold. It’s unnecessary for most trees, but it’s helpful in protecting young, thin-bark trees, such maples and fruit trees, for the first winter or two after planting.
- A rule of thumb is to wrap the tree at Thanksgiving and remove the wrap at the spring equinox. Always remove tree wrap in spring to avoid a spot where insects can gather and disease can take hold.
- To protect established trees from winter critters, create a barrier fence a couple of feet away from the trunk using stakes and mesh screen or plastic tree wrap. You can wrap the trunk itself with chicken wire or plastic wrap that has air holes for circulation, or a plastic drainage tube slit down the side to loosely cover the trunk. Again, always remove any barriers in the spring.
- Protect evergreens from drying winds and sunscald with burlap screening or wrapping on the south, southwest, and windward sides. Anti-desiccant sprays can help but may not be fully effective in all cases.