Garden Detective

I heard you're supposed to cover a poinsettia plant with a paper bag in October. Is this true and why?
Dera Grosso, Farmingville

Poinsettias are tropical plants that thrive outdoors in the right climate. Unfortunately, that isn't here. On Long Island, they're purchased mostly around the holidays and last for about a month or two.

If you'd like to try keeping them going as houseplants, continue to water them throughout the winter, keeping the soil moist. When the weather warms and nighttime lows are steadily above 60 degrees, you can place them outside, transplanting to a larger pot,

if necessary.

Cut back severely in early spring, and watch for new stem tips. You can keep pruning throughout the summer. Come fall, place the plant out of direct sunlight.

Here's where the paper bag comes in: Poinsettias require 14 hours of complete darkness every day for two or three months in the fall in order to set buds for a second bloom. To accomplish this, some people recommend bagging them in October, but that also requires taking them out of the bag each day so that they can get the recommended 10 hours of sunlight that they also require.

It makes more sense to me to place them in a closet for 14 hours at night and move them out for the remaining 10 hours. Come to think of it, it makes the most sense just to buy new ones every year. But that's me. If you're up for the challenge, have at it - and let me know how it works out.