Garden Q&A: it's time to transplant azalea
Q: I have an azalea bush that isn't in a very good place. It has barely grown in all the years it has been there. I'd like to transplant it to a place where it has more room to grow. When would be a good time to move it? Would working horse manure into the soil be a good fertilizer for it?
A: Fall is the perfect time to transplant your azalea, though I suggest you do it sooner rather than later. It's important to allow ample time for root establishment before the ground freezes.
As a matter of fact, fall is really a terrific time to move many different shrubs and perennials. It is a particularly good time because, despite the cooler air temperatures, the soil is still warm. The combination of cool air and warm soil promotes excellent root growth and minimal top growth — exactly the combination you want for optimizing new root production and reducing transplant shock.
Care should be taken in selecting a new site for your azalea. Keep in mind that they are an understory, woodland plant. They do not like full sun, and many times, when they are improperly sited, they are prone to developing infestations of azalea lace bugs. Select a site with morning or late afternoon sun, or one that is in dappled shade, but avoid the hot afternoon sun if you can.
Also be sure to dig up a wide root ball, ideally one that extends all the way to the plant's drip-line (the outermost edge of the foliage). The depth of the root ball doesn't matter as much as its width, but digging down a good 18 inches to 2 feet should be adequate. Carefully lift the root ball out of the hole and slide it onto a tarp. Drag the tarp to the new planting site and immediately dig the new hole.
The planting hole should be the same depth as the root ball but extend about twice as far out as its width. After the plant is positioned in the hole, backfill only with the soil originally removed from the hole. The addition of soil amendments like horse manure is no longer recommended at the time of planting. Doing so encourages roots to circle within that area, rather than encouraging the plant's roots to spread out into the existing soil. Save the horse manure for the vegetable garden.
And one final thing: Be sure to keep the transplanted azalea well-watered for the next year, including throughout winter if we don't get rain and the ground isn't frozen. You can fertilize it with an evergreen-specific granular fertilizer in spring.
Horticulturist Jessica Walliser co-hosts “The Organic Gardeners” at 7 a.m. Sundays on KDKA Radio. She is the author of several gardening books, including “Grow Organic” and “Good Bug, Bad Bug.” Her website is www.jessicawalliser.com.
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