Q&A: Winter-damaged Phormiums, pesky bamboo
A Q&A with garden writer Ciscoe Morris on reviving Phormiums damaged by winter and on a neighbor’s invasive bamboo.
Special to The Seattle Times
Northwest Flower & Garden Show: 9 a.m.-8 p.m. Feb. 6-8, 9 a.m.-6 p.m. Feb. 9. Display gardens, marketplace and seminars. Ciscoe Morris speaks Feb. 6 and 8. Washington State Convention Center, 800 Convention Place, Seattle; $22 general admission, various discounts on website, age 12 and under free (www.gardenshow.com).
Arboretum Foundation Display-Garden Plant Sale: 10 a.m. to 1 p.m. Feb. 15. Buy plants that were used in the Washington Park Arboretum’s display at the Northwest Flower & Garden Show. Graham Visitor Center, 2300 Arboretum Drive E., Seattle (www.arboretumfoundation.org).
‘What the Cluck? Free Range Chicken Gardens’: 10-11 a.m. Feb. 15. Learn the basics of integrating chickens into your garden. Swansons Nursery, 9701 15th Ave. N.W., Seattle; free (www.swansonsnursery.com).
Valentine Tea and Tour at Chase Garden: 11 a.m. -1 p.m. or 2-4 p.m. Feb. 15. Reserve and pay by Feb. 12. 16015 264th Street E., Orting, Pierce County; $12 members, $15 nonmembers (206-242-4040 or www.chasegarden.org).
In the Garden
Q: The foliage on my Phormiums and Cordyline plants are turning off-color and some are becoming mushy. Will they survive?
A: Phormium (New Zealand Flax) is an evergreen plant that is a natural for seaside gardens, thriving in wind and salt spray. Depending on the variety, the colorful, swordlike leaves can reach 6 feet tall and make a bold statement in the mixed border or in containers.
Although Phormiums are generally hardy in our area, harsh winters can wreak havoc with the foliage, leaving many, if not all, of the leaves dead and unsightly. Fortunately, the root systems survive in all but the coldest winters.
Remove damaged leaves by cutting them to the ground with sharp pruners. Sparklingly attractive new leaves will emerge to take their place. You’ll need to be patient, however. The leaves on these plants are notoriously slow growing, and it’ll take a couple of seasons before your plant will regain its former size and glory.
Cordyline australis is another New Zealand native. This one has an upright, tropical palm-tree look, with swordlike leaves that come in a variety of colors. Hardiness varies, with the standard green variety being able to withstand colder temperatures than the ones with colorful leaves, but even the standard species can be killed if temperatures dip into the teens for an extended period.
Fortunately, if temperatures don’t remain cold for an extended period, only the top of the plant is killed while the roots often survive. The only way to find out is to cut the dead top right to the ground in mid-March. It’ll take a while, but if the roots are still alive, two or more new stems will emerge.
I find that the plant will grow back faster if you remove all new stems except for the strongest one. Regrowth is usually stronger than you might expect, and you could easily have a 3-foot-tall specimen adding its unique tropical flair by the end of the season.
Q: My neighbor has running bamboo along her fence that has invaded my yard. If I install a barrier, or dig a trench, do I still need to dig up my yard and get all of the bamboo out or will it eventually die if I just keep cutting it down?
A: Once bamboo becomes established in your yard, cutting the culms (stems) every time it tries to grow won’t kill it. Having dealt with running bamboo several times in my gardening career, I can guarantee it will just keep coming back to haunt you unless you rid your garden of it. Evidently some people have had success, cutting the culms and hand painting round-up on each cut, but it’s a hazardous, unpleasant task requiring safety equipment and follow-up applications. In my opinion, as long as you can dig and move valued plants out of the way, you’re best off renting lots of digging tools and hiring day laborers to dig the bamboo roots out. It will be a big job, and you’ll have to be on guard to extricate any escapees that show up later, but it will rid your garden of the bamboo. Unfortunately, even if you install bamboo barrier, or dig a permanent trench, you’ll still need to patrol your property line every spring and fall and cut any runners that jump the barrier or grow through the trench. Bamboo shoots at the end of runners must remain attached to the mother plant for about a year before they can root and survive on their own to start a new colony, so as long as you cut the runners a couple of times a year, the bamboo won’t be able to reinfest your garden. Maybe the best solution would be to take a bottle of wine over to your neighbor’s house and see if you can persuade him or her to allow the day laborers to dig the bamboo from their garden at the same time. That would solve the problem once and for all.
Ciscoe Morris: email@example.com “Gardening With Ciscoe” airs at 10 a.m. Saturdays on KING 5.
About Ciscoe Morris
Ciscoe Morris' column runs Thursdays. His show "Gardening with Ciscoe" airs at 10 a.m. on Saturdays on King 5.