Transplant hydrangeas in the fall
Q. I need to transplant my hydrangea. I planted it two years ago. I didn’t leave enough room. I have heard conflicting instructions. Can I move it now, or wait until spring?
Julie from Poland
A. Julie, after checking many researched sites, the consensus is to move it in the fall, around November, when all the leaves have dropped and before the ground is frozen.
Now that you have the answer as to when to transplant, you need to know the proper way to transplant. Most hydrangeas have to be transplanted to a site about 3 feet in diameter. If you don’t, you’ll have to move it yet again in just two to three years.
All hydrangeas prefer partial shade to some sun (morning sun, not hot afternoon sun), with a moist, fertile, well-drained soil. It may take your plant a year or two after transplanting before vigorous growth appears.
Now that you have chosen your new location, you can begin to dig a hole at the new site. Make sure the soil in the hole is not wet. Do not dig up the plant first, as the roots will dry out and cause long-term damage.
You then need to amend the soil, as hydrangeas prefer more organic matter than is available in most soils here in the Mahoning Valley. Dig up the soil with a shovel, reaching a 3-by-3-foot area and as deep as the root ball you expect to dig up. If you’re transplanting a larger plant you may have to dig 3 feet deep to contain the roots. Break up all soil clumps. Add about a 9-inch layer of compost over the area and mix it with the loosened soil. The final hole needs to be only twice as wide as the hydrangea’s root ball, and just as deep.
Second, prepare to move the original plant. If your hydrangea shrub is unwieldy, prune it back. Dig a trench around the plant about 2 feet from the trunk. Push the shovel under the root ball and lift it out of the hole. Loosen the outside of the root ball with your fingers, but do not remove too much soil. Protect the roots.
Place the root ball into the new hole at the same depth as before. You may need to fill in the hole with soil to ensure it’s planted at the same depth. Gently firm the soil around the trunk, but do not tamp the soil over the roots with your foot. Water the soil well. Place 1 to 2 inches of organic mulch, such as shredded pine bark, around the plant. This will reduce heaving during winter’s freezes and thaws. Next spring and summer water frequently to help get the roots established in their new surroundings.
Today’s answer is provided by Barb Delisio, OSU Extension master gardener volunteer. Call the office hotline at 330-533-5538 to submit your questions. Regular clinic hours are 9 a.m. to noon Mondays and Thursdays.