Cocktail hour for paperwhite bulbs

Q: I remember reading something about using gin to keep the leaves of amaryllis plants from getting too tall and flopping over. Is that right? How does it work?

A: It is true that diluted alcohol has been shown to slow growth of foliage, but the research was on paperwhite narcissus, not amaryllis. This research was done at Cornell University with the support of the flower-bulb industry in the United States and the Netherlands.

Paperwhite narcissus are very popular bulbs in winter. They are easy to grow indoors in soil or, more commonly, in bowls of water with small rocks, large marbles or gravel to keep them stable. The flower stems show up rapidly, usually in two to three weeks, bearing white flowers. However, in warm homes, the stems and leaves tend to get too tall and flop.

Cornell researchers found that diluted solutions of alcohol kept stems and leaves one-third to one-half shorter than those of comparable bulbs growing in plain water. No staking or tying up were required, and the flowers opened to typical size and lasted as long as normal.

The key thing, the research showed, is to let the bulbs begin to develop roots in a bowl of plain water and their stone anchors until the shoots rise 1 to 2 inches above the top of the bulb. Then pour off the water and replace it with a solution of water containing 4 to 6 percent alcohol such as gin, vodka or rum. To get this percentage from a 40-percent distilled spirit, you would need 1 part liquor to 7 parts water. That yields a 5-percent solution, which is the amount used in the research on the popular paperwhite variety named Ziva.

Use this alcohol-water combination when you need to add water to the bowl. The Cornell scientists say rubbing alcohol also works. But because it is typically 70 percent alcohol, less is needed, just one part rubbing alcohol to 10 or 11 parts water.

For more on this, read the Cornell University report: www.hort.cornell.edu/miller/bulb.

I have found that growing paperwhites in pots of soil kept outdoors in cool weather results in stems and foliage that remain shorter than when grown indoors in water. But many people do not want to mess with soil, flower pots and saucers and prefer to grow these bulbs in their own glass, silver or ceramic bowls that suit a home's décor or the color scheme of a winter party.

Just remember that only the base of the bulb where the roots emerge should sit in the solution. The solution won't hold the bulbs in position. The little stones should do that. Attractive white ones look good. So do small rocks in any color and even little glass balls, provided they are sturdy ones, not thin and fragile.