September 30, 2011
OSU Extension Master Gardener Intern
With summer in the rear view mirror, a chill in the air, and a blush of color to the foliage of our deciduous trees, it is time to begin tying the loose ends in your garden before the end of the season. It seems that no matter how well-laid a garden plan is, every year there is at least one plant that needs to be transplanted. Not getting enough morning sun, not getting enough afternoon shade, filling out more than expected, etc. Variables that sometimes simply are not apparent until the plant has lived in the spot for a season. While sometimes frustrating, transplanting in a garden is actually a wonderful necessity that keeps the flow of the garden fresh and interesting. After all, the unknown is half the fun in gardening anyway. One of the troubles with transplanting is the timing. Often the decision is made in high summer that a particular plant needs to move, however this is a terrible time for transplanting. Then in the ideal transplanting window, mid-autumn, when most of us are not in the garden every day it easily slips the mind. With a few key specifications, transplanting success is quite attainable.
First of all, it is important to be realistic with yourself that the more established a plant is, the more danger there is involved with transplanting. For the most part, shrubs and small perennials are easier to transplant than trees. The difficulty in transplanting trees is when the tree is established in your landscape (more than two years), it will likely only be transplanted with 25 percent or less of its’ root system. The odds of survival are not impossible — but also not in your favor. Trees purchased from nurseries have had their root systems carefully pruned and manipulated so at time of original planting from nursery to ground they have about 75 percent of the root system intact. Transplanting trees can be done in early spring, before the buds begin to swell. Spring transplanting can be difficult in Ohio because of our unpredictable weather. Our frost-free date is not until May 15 which is already too late in the season considering the extreme heat that can be just around the corner as well. This year it was in the high 80s-low 90s Memorial Day weekend — too hot for a fresh transplant. For our growing area, fall transplanting is ideal.
Although our weather in the fall can also be unpredictable, the risk of the ground thawing and refreezing and killing a root system is far less likely. The time to transplant in the fall is when most of the leaves have fallen.
Now that you have assessed the risk and decided the right day for the transplant, there are a few details that make all the difference. First of all, it is best to transplant in the morning. Even though the sun does not feel particularly warm on our skin right now, it can still be enough to shock the plant in the process of the transplant. Another imperative detail is watering the plant thoroughly before, during and after the transplant. You want the root system to stay completely saturated. While the science is not the same, think of an ocean mammal like a dolphin that has become beached. The element most crucial to the dolphin’s survival is keeping the skin above water hydrated. Roots above ground are a similar situation. They are hypersensitive to the light and this is where most transplants fail. A successful transplant should be done in a matter of minutes. The new hole needs to be dug and saturated before removing the plant from its current position. It may need extra water through the end of the season and clearing excessive snow cover from it certainly is a good idea in the winter.
Although a transplant can sometimes be a roll of the dice, there are definite ways to improve the odds of enjoying an older plant in a new setting. That being said, do not let the sometimes daunting thought of a transplant stop you from rearranging your garden. Gardens are a year round project that are constantly changing. If a particular plant is not working in its original spot, it is better to try and save it with a transplant, than watch it under perform for years and never truly enjoy it.
Editor’s note: There are two corrections from this past Saturday’s Dig in with the Master Gardeners City of Delaware Tree Inventory.
It was noted in the original article that the writer recommended planting Japanese lilac trees and serviceberries under power lines. The writer recommends planting Ivory Silk Japanese lilac trees when there is afternoon shade, but he no longer recommends planting serviceberries. Also, the Emerald Ash Borer (EAB) has already impacted the value of the city’s urban forest by about $1 million, and the final loss is expected to be $1.3 million.