The Bay Gardener by Dr. Frank Gouin

You Don’t Have to Wait for Spring

Here’s how to force branches to flower now

By the last week in January, forsythia and quince plants should have received sufficient cold from Mother Nature that you can force them to flower. These two flowering shrubs have relatively short cold dormancy requirements as compared to crabapple, cherry and lilac. So if you’re itching to get a head start on spring, forsythia and flowering quince are dependable species to start with.

Select forsythia branches that still have brownish-yellow bark; avoid older branches covered with gray bark. Young stems are better able to absorb water over a longer period of time than older stems. Young branches of flowering quince tend to be reddish-brown in color. The bark of older stems is gray and smooth.

As soon as you prune the branches, immerse them in 100-degree water to force the stems. I recently overheard two garden club members talking about smashing the stems with a hammer to force the branches to absorb more water. There is no evidence that smashed stems absorb more water than properly cut stems placed in hot water.

To hasten flowering, place the cut stems in a warm room and wrap them with clear plastic such as Saran Wrap or the thin clear plastic used by dry-cleaners. By wrapping with plastic, you are creating a humidity chamber to hasten the opening of flower buds.

At this time of year, it will take two to three weeks before the flowers open. As spring approaches, flowers will open faster after being brought indoors. To maintain a succession of cut flowers, you will want to bring additional branches indoors in about three weeks.

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Wood Ash in the Garden

Q Have you tried applying wood ashes to poison ivy plants to kill them? I’m considering trying it out this spring because, as my husband has proved on more than one occasion, letting a clump of wood ashes stay in one spot in the lawn definitely kills any grass that was growing there.

–Theresa Hunter, Hollywood, MD

A I doubt very much if wood ashes will kill poison ivy. Poison ivy has a very extensive root system very different from lawn grasses. Wood ashes are rich in calcium oxide, better known as hydrated lime, and if not spread uniformly over an area will raise the pH very high quickly and will also burn plant tissues.

I spread wood ashes all over the cover crops in my garden every year as well as on the flower garden. I don’t have to add lime to the soil, and I have never killed any plants with ashes. For years I have recommended farmers use wood ashes, available from some wood burning heating plants, to raise the pH of soils. I have never heard of any plant injury. Wood ashes are only toxic in large concentrations applied to a small space.

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Bay Gardener Gives Lessons

Saturday noon lectures at Homestead Gardens, Davidsonville: 800-300-5631; www.homesteadgardens.com.

Jan. 23: Composting;

Jan. 30: Pruning.