We often think about planting trees in the spring, which is definitely a good time, but fall is also a good time to plant and establish new or replacement trees. There are some advantages and cautions about fall tree planting that should be considered before getting started.
One main advantage of fall planting is that the soil temperatures are warmer and this encourages root growth more quickly as compared to cool spring soils. If the roots are able to grow quickly this also means that a fall planted tree is able to become established sooner than a spring-planted tree and will be more prepared for the heat stress next summer.
It is important to choose a tree recommended for Central Kansas. The list below is a good starting point when investigating trees for your site.
Tips for fall tree planting:
1. Make sure to plant at the correct time. If an evergreen tree or shrub is to be planted it should be by mid to late September. These plants ideally need at least 6 weeks to establish themselves before the first killing frost. If not established properly they can be more susceptible to winter injury and desiccation from cold and wind. Deciduous trees (those that drop their leaves) may be planted later in the fall than evergreens but the benefits of warm soil and quick root growth are lost the later the tree is planted. Deciduous trees are less prone to winter damage but must still receive proper care to survive the winter.
2. For ball-in-burlap or containerized trees dig the hole two to three times wider than the rootball. Dig the depth of the hole 2 or 3 inches less than the height of the rootball. The first root (flare root) coming off the tree trunk should at or just above ground level and no deeper.
One of the most common planting mistakes is planting trees too deep. As little as two inches too deep can create long term problems for tree roots. Always set the root ball on undisturbed soil in the bottom of the hole. It is important to dig a wide hole and loosen soil around the sides of the root ball because tree roots grow outward.
3. Deal with girdling or matted roots. Containerized trees may have circling or matted roots that will need to be shaved, cut or teased out to prevent girdling (roots growing around and damaging the tree trunk) later on. Girdling roots can be cut with pruners or a hand saw if needed. Stopping circling roots now will prevent major problems for the tree decades later.
Stem girdling roots – Fixing stem girdling roots is an important practice when planting woody plants. Even quick-growing annuals often fail to develop a good root system if circling roots are not teased out. Roots growing in a tight circle will continue to circle after the plant is in the ground.
Matted roots – If a plant’s root ball is matted with roots, either pull the root ball apart with your hands or make several cuts down the side of the root ball to loosen it. Pull the root mass apart and spread the roots out in the planting hole.
This 10 year old oak is starting to decline due to the effects of stem girdling roots that were not dealt with at planting time. This is a frustrating situation that can be avoided.
4. Once the tree is in the hole, backfill with the original soil. It isn’t recommended to add compost, peat, or other organic materials to the backfill. Peat or organic matter addition as backfill to the planting hole can lead to problems with water moving in and out of the root ball and the tree settling too deep in the hole as the organic matter decays.
It is possible to amend the planting site (for example- a 10×10 area where the tree is to be planted) with organic matter ahead of planting the tree, but amending only the planting hole can negatively influence water movement into or out of the root ball, and it does not help root establishment.
5. Mulching around the tree is highly recommended and will moderate soil temperature and moisture fluctuations. Be careful not to pile the mulch directly up the tree trunk itself since this can allow more points of disease entry and harbor bark chewing rodents like voles. Keep the mulch thickness to around 3 inches or less.
6. Trunk protection with a tree wrap or guard is recommended on newly planted trees to prevent freezing and thawing cracks that often occur on thin young bark during the winter temperature fluctuations. Staking may also be necessary for long or leggy trees.
7. Consistent watering will be a must for new trees. Trees should be watered well at planting and on a regular basis during the remainder of the year. Frequently check the moisture status of the tree’s rootball. Water newly planted trees when the rootball begins to dry out but do not overwater. Continue watering until the ground freezes in winter and even during the winter at least once or twice a month (as needed) on warm days to avoid winter injury.
Fertilization: When it comes to fertilization, it is best to wait to fertilize until the tree has had time to begin establishing roots in the new site before a fertilization program is started. A soil test will provide the best information about how to fertilize the new tree.