Good bets for pruning twig dogwoods; woolly apple aphids
Garden writer Ciscoe Morris answers questions about pruning a twig dogwood and fending off woolly apple aphids.
Special to The Seattle Times
Amy Stewart: Author of “The Drunken Botanist: The Plants That Create the World’s Great Drinks” will appear at 7 p.m. Thursday, Third Place Books, 17171 Bothell Way N.E., Lake Forest Park (www.thirdplacebooks.com) and at 7 p.m. Friday at Village Books, 1200 11th St., Bellingham; (www.villagebooks.com).
“Celebrate Urban Nature”: Family activities, dedication of the Resource Conservation Landscape, an educational garden. 10:30 a.m.- 2:30 p.m. Saturday at Magnuson Community Center, 7110 62nd Ave. NE, Seattle; $3-$8 (www.magnusonnatureprograms.com).
Skagit Valley Tulip Festival: April 1-30, bloom dates are up to Mother Nature; www.tulipfestival.org.
In the Garden
Q: My wife wants to cut our 12-foot red twig dogwood practically to the ground, because only the twigs at the top of the shrub are colorful. I told her it would kill it. Am I right?
A: Don’t bet a bottle of good wine on it. I’ve always recommended pruning twig dogwoods down to 4 inches tall in spring as long as you start the practice the year after you plant them. Cutting them back each spring is a great way to limit height; plus the shrub stays much more attractive because the bark on the new twigs that emerge from the base is much more colorful than the gray bark on older growth. I never recommended cutting a well-established twig dogwood, however, because I knew that once most any kind of shrub gets tall and develops a wide trunk at the base they rarely survive being cut practically to the ground. That all changed a number of years ago when my wife decided to cut her 14-plus-footer to 4 inches tall. I was so sure it would kill it, I wagered a bottle of good French wine on it. She loved that wine! The dogwood sprouted gazillions of spectacularly colorful twigs right out of the 4-inch stump, and has continued to do so when she cuts the twigs back every spring since. The one exception is if your twig dogwood is growing in the shade or lacking vigor. If that is the case, cut only a third of the twigs down each year. If it is growing in shade and your wife insists on cutting it down, bet a good vintage. You’re going to get to enjoy it.
Q: My apple trees develop large, dense growths over every pruning cut. What is this?
A: Your tree is infested with woolly apple aphids. This is a relatively common pest of apple trees in our area, but there are so many beneficial insects and birds that feed on them, the woolly apple aphids rarely build up to damaging numbers. Occasionally, however, the aphid populations explode. When that happens, the knotlike galls occur where large groups of them feed together. The galls can result in reduced fruit production, but if the problem is not dealt with and populations get extremely high, the aphids migrate to the roots in winter. This causes similar growths on the roots which can interfere with water and nutrient uptake weakening the tree over time. To keep populations in check, look for areas with cottony build ups (the aphids are covered with a woolly substance) and spray until saturated with pesticidal soap, available at most nurseries. The soap should do in the troublemakers while sparing the beneficials that will help keep the ones you missed from re-establishing damaging populations.
Ciscoe Morris: firstname.lastname@example.org “Gardening With Ciscoe” airs at 10 a.m. Saturdays on KING-TV.
About Ciscoe Morris
Ciscoe Morris' column runs Thursdays. His show "Gardening with Ciscoe" airs at 10 a.m. on Saturdays on King 5.