If you realize that your plant is root bound in the middle of Winter, it doesn't mean it's the right time to root prune it! All “invasive plant procedures” such as; repotting, pruning and root pruning need to be done in Spring, (Summer is OK too).
For most plants, root pruning is recommended in the fall, followed by transplanting in the spring. This allows the plant to grow new feeder roots in the pruned zone over the winter without the burden of supporting new growth. For larger plants, you may want to root prune one year or more before transplanting.
The first step of root pruning is knowing when to do it. If your plant is root bound, it is time to prune! However, if you want to prevent your plant from becoming root bound and stressed from an overly small pot, you should do some root pruning maintenance every two to three years.
Now, here's how to cut tree roots:
It should be 10 to 12 inches for each inch of trunk diameter. Mark a circle around the tree that's the width of the new root ball. At least 24 hours before cutting roots, water the soil. With a sharp spade, use the circle as a guide to cut into tree roots, going about a foot deep.
If done properly, root pruning can improve the plant's growth and overall health. This is especially true with container plants that can become “pot-bound,” with the roots girdling around the inside of the pot. This also means those roots can't take up enough nutrients and water to support the plant.
Pruning wounds root tissues, making them vulnerable to infection [6, 7]. In addition, trimming reduces the vigor of young vines, likely due to a smaller root system and subsequent reduced water uptake and transpiration [8, 9].
Root pruning is the process of cutting roots prior to mechanical excavation near a tree. Root pruning may be necessary to minimize damage to the tree's root system during construction or in preparation for large tree transplanting.
Pruning Effect on Root Growth
Any pruning of living tissue will affect root growth to some extent. Pruning back active branches diminishes a tree's ability to produce food, so there will be less root growth.
Root pruning also makes more smaller roots to grow within the soil in the polypots and makes the stem of the seedling at soil level grow thicker and harder. All these make the seedling better able to survive and grow after planting out.
Root pruning shall be done with a sharp tool, in such a way that does not pull on the roots, but leaves smooth cuts. It is preferable to expose the roots prior to root pruning. After pruning, fill the area with quality topsoil and water until thoroughly soaked. Once exposed, roots must be covered within 8 hours.
Most plants will tolerate simple root pruning. You will want to do root cutting on the thread roots, not the tap roots. The tap roots will be the larger roots and the thread roots will be the small roots that grow off the tap roots.
Plants are more brittle in cold temperatures. Messing around with them may cause branches to snap and split unintentionally. It's minor, but it could impact the look of a plant or create a haven for insects and diseases later. Don't prune when the temperature falls below 25°F.
If you want to keep your plant small, you can accomplish this by trimming the roots, but it's quite an exact science, and if you do it for a long time, you can damage the plant and risk killing it. However, a quick trim because your plant is super root bound and you don't currently have another pot is fine, but tricky.
You should not do aggressive pruning in summer. Major structural pruning should wait until the plant is dormant in winter. Improper pruning will stress the plant. You might cut off valuable buds.
Few plants are pruned this time of year because pruning encourages new growth that does not have time to harden off before winter. Late-season pruning typically does more harm than good.
In summer, leaves engage in photosynthesis and produce carbohydrates. The tree translocates those carbohydrates throughout to grow roots, shoots, leaves, and fruit. By removing leaves during summer pruning you remove a resource point and thus reduce energy for overall tree growth or regrowth.
Root growth is not slowed by tree topping. In fact, it can make roots grow faster causing more risk to your property. If you are concerned about damage to foundations, sidewalks, driveways, pipes, and so forth, ask a Certified Arborist about proper root training and pruning.
By removing the apex, pruning temporarily destroys apical dominance and stimulates the growth of lateral buds into shoots. Figure 4. Pruning stimulates lateral shoot growth close to the cut. Pruning also reduces the size of the above-ground portion of the plant in relation to the root system (Fig.
Root pruning is the process of slicing through the roots at the drip line of an establish ed tree that is going to be dug and transplanted. This is done to encourage the growth of new feeder roots along the root ball that will be transplanted along with the tree.
Phosphorus potassium &Nitrogen are the essential nutrients to support root growth for plants. They encourage plants to put down a dense collection of new roots and strengthen existing roots as they develop. Phosphorus helps establish healthy root systems at the beginning of growth.
Trim the Roots
To prune the roots, start with a pair of scissors, pruning shears, or sharp knife. Cut around and under the plant's root ball, removing both roots and soil. You can be pretty aggressive, cutting away both large and small roots.
Warm growing medium temperatures accelerate cell division which leads to faster callusing, root initial development and subsequent root growth. It also speeds up the dry-down rate of the growing medium, which also helps encourage better rooting. The best way to warm the growing medium is through bottom heat.
Cut roots as far away from the trunk as possible.
A good way to decide is to measure the distance of the cut from the tree trunk and compare it to the trunk's diameter. See diagram below. Ideally, cut roots at a distance equal to at least 3-5 times the trunk diameter away from the trunk base.
What is improper pruning? Cutting too close to the nodes or too far from the trunk is referred to as improper pruning. It can cause irreversible damage to your plants.