Transplanting Trees

By J.B. McGowan

I know spring gardening is well underway when questions arise about two of the season's best ornamentals: lilacs and dogwoods. Here are some tips for successful transplanting of these wonderful spring bloomers.?

Q: I would like to have lilac bushes in my back yard. I have the chance to transplant some young plants to my back yard. My questions are: when is the best time to do this transplanting, what is the recommended procedure, and what should be used as fertilizer or a base for the roots?

Transplant young lilac bushes in early spring or right after they blossom so you don't lose the current year's display. If you have a lot of top growth but sparse root support after digging out the plant, you may want to prune the branches.

Be sure you have at least 8 inches of good, well-drained soil in full sun. Lilacs can grow in less soil. But why go to all the bother of pruning and transplanting
?and then not prepare a good site?

Mix in some composted manure or organic compost with your soil and you shouldn't need to worry about fertilizing anytime soon. But don't limit the compost just to the planting hole. Dig it into a wider area to encourage the shrub to spread its roots.

If your soil is very acidic, work some limestone in once a year. Mulch the soil with composted bark mulch. This will keep down weeds. It will also help with watering, which should be done several times a week for the first few weeks, especially if it has been dry.

Once your lilac has settled in and starts blossoming, trim the spent flower stalks to encourage greater blooming.

Pruning will help the shrub put more energy into re-rooting itself rather than trying to support a large top growth. Of course, pruning will decrease your flowering for the next season.

The worst time to prune is late in the season, as lilacs will flower next season on this year's growth.

If what you are getting is Syringa vulgaris (common lilac), it is the toughest of the tough, which is great. But remember, one of the reasons you may be lucky to get some young plants is that the common lilac suckers profusely. Keep this in mind when you choose your planting site.

Q: We transplanted two white flowering dogwood trees about one week ago. Now the leaves are droopy, turning yellowish/brown, and seem to be dying. Is this normal transplanting trauma, or have I done something wrong? The trees were originally planted in an overly shaded area and not growing well. They are about 3 feet tall, and were already in leaf when transplanted. We planted in holes approximately twice the size of the root ball, with the top of the root ball approximately 1/2 inch above the soil line. We used topsoil for transplanting, and I covered the area around the trunk with a weed prevention sheet commonly used in gardening. I then mulched around the trees using approximately 3inches of mulch. They have been watered daily, and I have also used Miracle-Gro according to the box directions.

Transplanting is always a shock to a tree, especially if it is already in leaf. But that is also the case with every nursery grown potted or burlap wrapped plant.

If your trees were already settled in the ground, it is quite possible that you left some of the roots behind or damaged some in the process. That isn't necessarily fatal, but the root system that supported the tree branches and leaves is temporarily incomplete.

If the trees have been in shade, the shock of transplanting and putting them in sun, particularly hot, dry sun, would also take a toll. You may want to shade the trees with landscape cloth on stakes or some other means to help them ease into their new sunnier location. How about using that beach umbrella?

I'm not sure why you planted the tree with a half-inch of the root ball above the soil line. In most cases, trees should be planted at the same level as they were previously planted. This is especially true of trees that have already been in the ground.?

Perhaps with the landscape cloth and the mulch on top this will not be a problem. By the way, make sure you are using landscape cloth that allows water to seep through and air to circulate. Do not use impermeable plastic like trash bags.

Your bark mulch should be the composted kind, not freshly chipped bark. Fresh bark chips will rob the soil of nitrogen. If you bought your bark mulch in bags from a store, you should be all set. Or if you got it from a garden center and it a dark color, it probably has been composted sufficiently. Ask if you're not sure. Be sure to keep the bark mulch a few inches away from the tree trunks to deter insects such as borers from using it as a place to nest and gain access to your trees.

You are wise to keep your trees watered, but be careful. Yellowing leaves can also be a sign of over watering. The best way to avoid over watering is to have good drainage. The water should not run through quickly, nor should it sit in a puddle for a long time. Try not to wet the leaves when watering. Dogwoods, especially Cornus florida, are susceptible to dogwood anthracnose. Cool, damp conditions help spread the disease.

Stop using fertilizers on the trees for now. Fertilizers, especially those high in nitrogen, will encourage the tree to put out new green growth. If you have a damaged or reduced root system, the trees don't need more leaves to support.

Commercial products that aid in transplantation by encouraging root growth rather than top growth are available. I have used Miracle Gro Quick Start, but there are other companies with similar products, as well as organic products. I suggest you call your local garden center, nursery or cooperative extension service to see what they recommend. If you began with good soil with plenty of organic material in it, that should be sufficient for now without supplemental fertilizers.

Photos by the Michigan State University Extension Service.

J. B. McGowan is an avid gardener whose midcoast Maine perennial gardens have been featured in local publications and on house and garden tours.