Garden Plot: Plucked poison ivy still a perilous problem

A goat grazes in the brush in a fenced off area at Congressional Cemetery. More than 100 goats took over the cemetery to help clean up brush in an area away from the graves. The goats grazed for six days to eliminate vines, poison ivy and weeds. (AP Photo/Charles Dharapak)

Poison ivy plucked can still pose a perilous problem

Mark in Poolesville writes: “I’m curious if poison ivy leaches into the soil. I
removed all of the above-ground growth, but there are still thick roots in the
ground and some thicker stems above ground. Is it safe to plant grapes or other
fruits there?”

The allergenic oil in poison ivy doesn’t migrate into the soil, Mark, but it is
active in the roots and stems as well as the leaves. Touch any part of the plant –
– including the roots -— and you risk getting a rash. (About 25 percent of the
population can handle the plant without peril; the rest of us react.) And the odds
are strong that those roots will soon regrow their vines, so you should really
clear the area completely before you think about planting there.

To do so safely and effectively, soak the soil thoroughly with water (which makes
getting the entire root much easier; don’t be afraid to have a hose dripping right
next to the roots while you work). Then pull the well-saturated roots out
slowly with heavy plastic bags covering both your hands. Drop the roots into a
thick trash bag and continue, while chanting, “don’t touch your face; don’t touch
your face” until you’re done. (Oh — and don’t touch your face!)

Use a fresh bag to safely pull the bags off your hands when you’re finished and
dispose of everything in the trash. Then rinse your hands and arms down with cool
water —- no soap, no washrag, no jewelweed. Just cool clean water completely
dissolves the oil.

Don’t use gloves to pull poison ivy; they’ll become contaminated with the oil and
give you a rash every time you touch them.

Improving clay soil, one long toss at a time

Vicky in Laurel writes: “I want to create flower beds around a portion of my house
— one wall facing north, another facing south. Do you have a guide to converting
the native clay soil to a more nourishing and accommodating flower bed?”

Yes, Vicky — dig out as much of the clay as you can and toss it as far away as you
can. Clay soil is much better for making pots than growing plants. Then build nice
raised beds and fill them with a mixture of topsoil, compost and perlite (a mined
volcanic mineral popped into little white balls, available in bags at any big
garden center). Your plants will thrive with the good drainage and natural
nutrition this combination provides.

Just don’t locate the beds where they’ll be touching the actual house. To keep
subterranean termites at bay, you always want to keep a foot of open space next to
your foundation.

Did wicked winter wipe out fig trees?

Harvey in Silver Spring and Carrie in McLean are among the many who report that
their fig trees did not seem to survive our harsh, horrid winter. “What can we do
to see if they’re still alive?” writes Harvey. “Will new shoots come up from the

“How long should I wait to be sure?” chimes in Carrie, who adds, “If I cut it down
to ground level, is there a chance it will come back?”

It’s common for fig trees to suffer some winter damage in our region, especially
if they’re growing out in the open. Actual death by winter is unusual, but this
was an unusual winter. If you have a fig tree that still shows no sign of new
green growth, cut it back to about a foot tall. If the root has survived, you
won’t get figs this season, but the tree itself will begin to grow back. If no
green appears within a few weeks after pruning, it’s dead.

And take this harsh lesson to heart. Our long run of warm winters has lulled us
into forgetting that some plants, like figs and rosemary, can’t take prolonged,
bitter cold. To better their chances of survival, position tender new plants in an
area with excellent drainage that’s somewhat protected by nearby structures, not
out in the open, and wait to prune off any winter damaged areas in the spring.

Fall pruning = A really most sincerely dead fig

Phil, who lives in in Rockville writes: “The fig tree in my back
yard produced bushels of figs every August. In November, I trimmed it back,
thinking it would encourage new growth and get rid of branches that were too high
to reach. Unfortunately, the tree died. My wife claims that trimming the tree
killed it. What do you think killed the tree? And how can I avoid this in the

You killed the tree, Phil. No plant should ever be pruned in the fall. It prevents
them from going dormant and leaves them wide open to massive winter injury, and
this past winter provided a record amount of that injury. Your pruning did
‘stimulate new growth’— but at the worst possible time.

Replace it with a new fig that you will only prune in the spring, right after new
growth appears, which is also when you would prune to control height. Oh, and just
to be safe, tell your wife to hide the pruners after the 4th of July.

Hydrangeas: Old growth gone, but the plants survive

Cheryl in Fairfax writes: “I have over a hundred usually gorgeous hydrangeas, but
many suffered serious damage from a late spring frost. Only a few stray leaves
have appeared on the old branches, but they all show vigorous new growth at the
base. At what point should I cut off the old growth?”

The same thing happened to many hydrangea plantings this year, Cheryl, including
mine. I bit the bullet and cut back all the old stems to about a foot tall a week
ago and the plants look much better for it. I don’t intend to cut them all the way
back because these plants have a habit of surprise resurrection and I always like
to give my perennials every possible chance. And even though most hydrangeas
‘only bloom on old wood,’ I would not be surprised to see some flowers from this
year’s growth — they can be surprisingly plucky plants.

At least we can take solace in the fact that the roots didn’t die and all that
new greenery holds the promise of flowers next season.

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