|10 Tips For Minimizing Transplant Shock|
|Secrets To Successful Transplanting|
|James Kohut, Staff Writer|
At one time or another in their lives, most homeowners and gardeners will transplant trees and shrubs. To some it is a mundane task, while others are petrified of the experience. Surprisingly, many novices and pros alike are misinformed or just aren't quite sure about the proper techniques for transplanting and the ways to improve the success of a transplant and minimize the effects of transplant shock. There are a number of urban legends out there, many without any scientific basis, and trial and error is a tough road to take when you want your yard to look as good as it can as fast as it can.
Transplant shock is a reality in the plant world, but it is manageable. The bottom line is that there are things that homeowners and gardeners can and should do to help out their transplants and ensure the highest probability of a successful move. We've put together a listing of ten key tips that will help out your new trees and shrubs immensely. But before you get to these points, you need to know a few things about how transplanting affects trees and shrubs, and a little problem you're more than likely to experience called "transplant shock". As always, knowledge is your best defense.
The Roots Of Transplant Shock
More often than not, newly transplanted trees or shrubs will experience some degree of transplant shock. This is simply the plant reacting to having been moved. It is generally caused by damage to the roots of the plant during the transplant. While the thickest roots are nearest to the root ball, the most important roots, those that actually "do the work", are located the farthest away from the plant. These tiny roots are covered by even tinier hairs which absorb most of the water that is eventually carried to the top-growth of the plant.
During a transplant, these fine roots are usually destroyed either by being cut to keep the root ball size down, by drying out (some accounts say it only takes 3-4 minutes of exposure to air for these to die), or simply by being jarred and jostled around in the move. As a result of the loss of these feeder roots, the plant is not able to draw the amount of moisture it requires to thrive and grow. The resulting imbalance between the moisture demands of the top-growth and the reduced ability of the roots to meet those demands manifests as transplant shock. Besides major effects on the roots, plants can also sense subtle changes like wind, light and temperature, and take some time to re-adjust themselves to these new factors and cues after a move.
Transplant shock usually appears as some form of stunting of the new growth of the season. The plant may grow vigorously for a time and then suddenly stop growing. It may grow lackadaisically all season, or the buds may barely break and produce the smallest, most stunted leaves and virtually no new branch length. In severe cases, the buds may not break at all for an entire season, which usually comes with the worst prognosis. Transplant shock may manifest in other ways as well. It can cause unusual development of leaves and stems. Leaves can emerge and then promptly start browning along the edges or at the tips. Often times transplant shock can mimic other troubles like insect damage or disease.
Trees and shrubs can come into your yard in a number of ways, each with advantages and disadvantages that necessitate special considerations;
Container Grown - The plants have been growing in a container or pot for at least one full growing season and winter. Some plants have been grown in containers all their lives, while others were field dug and then potted into containers in previous years. These are the very best kinds of transplants, and are the least likely to experience transplant shock. Be careful, though, as some shady nurseries may peddle a plant as container grown when it was in fact field dug that same season, and will behave as such for all purposes. Some of the better growers will use a technique known as "pot-in-pot" which allows for field dug plants to grow in their pots for at least one full year before being shipped to the nurseries - these are ones to seek out!
Field Dug - Many plants are grown in a field on a plant farm. They are then dug out and placed into pots to be put on display for sale at the nurseries. When dug out, they are either dug with soil or moved bare-root. The success of transplanting tends to depend on how long they have been growing in the pot since being moved from the field; a full season is ideal, but rare. Many are actually potted in spring and then placed directly on sale. Because the roots haven't had time to actually grow in the new soil, the root balls often break, and the plant effectively becomes a bare-root transplant - beware of these! On the other hand, some better growers will use a technique known as "root pruning" to slowly adjust the roots of field-grown plants to a container size before they are actually moved - again, these will always perform better.
Balled And Burlapped - In this method of transplanting, the tree or shrub is dug from the field with as large a root ball as possible, including the soil. The root ball is wrapped in burlap which is then tied down to keep it intact. Unfortunately, many of the finer roots are still lost in the digging process, so these kind of moves tend to be quite susceptible to transplant shock, although they will usually recover. It all depends on how much of the roots were taken in the move - the more, the better!
Bare Root - Believe it or not, some trees and shrubs can be successfully transplanted without any soil on the roots at all! The trick is to move them when they are fully dormant, either in late fall or early spring. Once the leaf buds have broken for the year, the chances of a successful transplant diminish exponentially. If you buy a bare-root plant, always check the buds to be sure they have not broken, or you're asking for trouble. Be sure to plant it immediately when you get home - every hour of delay is costly to the plant. And a word of caution - this technique only works with some species, not all. If in doubt, get a guarantee from the nursery or garden center selling you the plant!
Machine-Dug - This is where professional tree movers drive into a growing field with a truck which has a large tree spade attached, dig out the tree and move it, root ball and all, to its new planting location. The success of this technique, like the others, is fully dependent on how much of the root ball can be moved intact. Generally speaking, the larger the tree, the more likely it is to experience severe transplant shock.
Gardener-Moved - Many people simply take out a spade and move that tree or shrub from one place in the yard to another, or from a ditch or forest nearby (without commenting on the legality of this practice) in their yard. Again, the success of such a transplant will depend heavily on how much of the roots can be moved, on the species being moved, and whether or not the plant was dormant at the time.
Knowing this, here are 10 useful tips to help your trees and shrubs through any transplant shock.
1. Select the healthiest looking plants at the nursery.
You're paying your hard-earned money for your trees and shrubs, so you have a right to demand the very best plants your money can buy. Inspect them carefully before buying. Check for evidence of insects, diseased foliage or stunted growth. Avoid plants that have experienced obvious physical damage like nicks, cuts, broken limbs, tattered leaves or those that are clearly spindly and weak. These plants are already under stress from being moved alone; the last thing they need is other stresses on top of the stress of transplanting.
2. Test container grown plants for root ball integrity at the nursery.
Not all plants sitting in pots on the nursery floor are truly "container grown". In some cases, they were received at the nursery bare-root that spring and then stuck into pots with some loose soil, following which they were immediately put out on sale. There is a huge difference in how likely these are to survive, so before purchasing a tree or shrub, do a simple test (or ask the nursery to do it for you, and be aware - most won't like you doing this because of what it might reveal!) by grasping the tree or shrub at the base and then gently tugging it out of the pot. If it comes out as a solid mass shaped like the pot, you can consider it a container-grown plant. If the plant starts to pull out of the soil or the soil breaks apart - buyer beware!
3. The best transplanting time depends on the type of transplant.
The best time to transplant any plant is while plant is still dormant, that is either in early spring before the buds have swelled and broken, or in late fall after the leaves have fallen (use it as a guideline for evergreens). This is the safest time for all the above transplanting methods. And for bare-root, it is the ONLY acceptable time to transplant. With field-dug, machine-dug and balled and burlapped plants, it will afford the greatest chance of success; avoid moving these kinds in the heat of summer. On the other hand, truly container-grown plants can be moved at any time between thaw and freeze-up.
4. Proper planting is critical for root development.
This cannot be repeated enough; a successful transplant is utterly dependent on how the plant is planted in its new home. Rather than going into great detail on the ins and outs of proper planting, check out this Info Sheet - "Digging The $100 Hole". Read it carefully and do as it says!
5. Only fertilize with root boosters the first year.
The eager gardener is often tempted to force the plant into a growth spurt as soon as it arrives in their yard by giving it a jolt of fertilizer. While this is actually a good thing with annuals and even most perennials, it could spell disaster for trees and shrubs. Unless they were container grown, their roots have been compromised, and the last thing they need is to be driven into vigorous growth without first having a root system which can support it. Devote the first year to promoting healthy root growth by mixing a root-boosting fertilizer such as bonemeal, bloodmeal or a micorrhyzal stimulant with the planting soil, and stay away from high-nitrogen fertilizers until the plants are fully settled in, i.e. at least one full growing season.
6. Manage watering religiously.
Newly planted trees and shrubs do not have the kind of root systems they need to handle drought or excess water stresses. So, ensure they experience neither of these in their first year or two. Keep the soil evenly moist throughout the entire growing season by watering when necessary, but not watering when it's not necessary (as obvious as that might sound, too many people miss that point!). "Even moisture" is best tested by sticking your finger about an inch into the soil near the base of the plant. It should be detectably moist - if not, it's time to water.
7. Stake young trees to minimize damage to developing roots.
Besides feeding plants, roots also anchor them into the ground. High winds can jostle newly planted trees and shrubs around, tearing new roots that are trying to grow into the soil. This is particularly a problem with top-heavy trees. Use a two-stake method (at 180° apart) to firmly secure the tree for the first year or two. But be sure to remove the stakes after this time, otherwise the tree may develop a weak trunk (winds actually help to strengthen the trunk). The objective is to keep the stakes in place until the tree has developed enough roots to anchor itself against the winds.
8. The jury is out on whether or not to prune the top growth of new transplants for balance.
There is a common theory out there that it is beneficial to prune out some of the top growth of the newly moved tree or shrub, in order to reduce the demands on the compromised root system. However, testing of this theory has at best provided inconclusive results. The most convincing argument is that leaving the top-growth untouched actually stimulates vigorous root growth as the plant naturally tries to regain balance, Besides, the plant gets its energy from the top growth and would likely be subjected to a deficiency of energy. Finally, the roots have already been stressed, so why now stress the above-ground parts as well? If in doubt, don't prune for balance - just let the tree or shrub take its natural course of healing.
9. Watch your new tree or shrub like a hawk.
Your new transplant is likely stressed to begin with from the move alone. The last thing it needs is troubles with insects or disease to add to its misery. Keep a close eye on the plant the first year. Carefully examine the leaves and stems for insects top and bottom. Transplant shock may manifest as a myriad of symptoms, and it can often be difficult to tell whether a particular effect is from the transplant shock or something else that demands attention. When in doubt (and where possible), snip off a sample of the afflicted area, place it in a sealed plastic bag, and bring it into the nursery or garden center where you purchased it. Ask to speak to their plant experts. Get them to positively identify the problem, and to suggest a remedial course of action. If it's transplant shock, patience is your best course. If not, follow their advice and deal with the stress immediately.
10. Patience will be necessary on your part.
Face it, trees and shrubs were never intended to be moved by nature, so they don't respond well to it, even in the best of circumstances. Transplant shock should be expected the first year - be thankful if your plants dodge it! More often than not, your plants will take a full growing season or even more to adjust to their new surroundings and to compensate for the stresses of transplanting. Allow them this time, and don't try to force them to grow and perform as soon as they get home! Your plants may not look happy for a year or two; just accept this and do your best to help them out. In time, they will recover from the transplant and then get down to the business of doing what they do best - looking great in your yard!