Long Island Horticultural Society

What's Going on in the Garden

December To Do List

Caring for Holiday Favorites

Pointsettia With care, poinsettias should retain their beauty for weeks and some varieties will stay attractive for months. After you have made your poinsettia selection, make sure it is wrapped properly because exposure to low temperatures even for a few minutes can damage the bracts and leaves. Unwrap your poinsettia carefully and place in indirect light. Six hours of light daily is ideal. Keep the plant from touching cold windows.Keep poinsettias away from warm or cold drafts from radiators, air registers or open doors and windows. Ideally poinsettias require daytime temperatures of 60 to 70°F and night time temperatures around 55°F. High temperatures will shorten the plant’s life. Move the plant to a cooler room at night, if possible. Check the soil daily. Be sure to punch holes in foil so water can drain into a saucer. Water when soil is dry. Allow water to drain into the saucer and discard excess water. Wilted plants will tend to drop bracts sooner. Fertilize the poinsettia if you keep it past the holiday season. Apply a houseplant fertilizer once a month. Do not fertilize when it is in bloom. With good care, a poinsettia will last 6-8 weeks in your home.

Cyclamen care starts with the correct temperature. In nature, cyclamens grow in cool, humid environments. If the temperature of your house is over 68 F. (20 C.) during the day and 50 F. (10 C.) at night, your cyclamen will start to die slowly. Temperatures that are too high will cause the plant to begin to yellow, and the flowers will fade rapidly.

While in bloom, keep the root ball moist and feed the plant every two weeks. Cyclamen should be kept moist by watering in a tray and allowing the roots to take up the water rather than watering from above the plant which can lead to rotting. Remove yellow leaves and spent flowers. Soak the soil thoroughly and let any excess water drain away.

Amaryllis Few bulbs are easier to grow than amaryllis — and few bloom with greater exuberance and beauty. Just plant the bulb in good potting soil, water regularly and provide bright, indirect light. A support stake is handy for keeping the blooms upright, but little else is required. Most varieties will begin blooming six to eight weeks after planting; some can take as long as ten weeks.

If your amaryllis is not already potted, plant each amaryllis bulb in a 6-8" pot. Heavy pots are preferable because lightweight pots may tip over under the weight of the blooms.

Plant the bulb, pointed-end-up, in potting mix. Pack the soil gently around the bulb so approximately one-third of the bulb remains above the soil line. It usually takes six to eight weeks for amaryllis to bloom. To prolong the blooms, keep the pot out of direct sunlight.

Paperwhites The most common way to grow paperwhites is to grow them to bloom in pots indoors. Fill a 3-4 inch deep bowl or other shallow container without drainage holes with crushed rock, pebbles, or other decorative stones. Pack your paperwhite bulbs into the container and push them down into the stones so the tips stay upright. Add water until it just covers the bottom of the bulbs.

After planting, keep the bulbs in a cool, 65 degree, dark room for several weeks until the roots take hold and shoots start to sprout from the bulbs. Then place the containers in a cool, sunny location. In 4-6 weeks, you'll see tiny blossoms on the flower stems. Paperwhites have a significant advantage over other commonly forced bulbs in that they do not need an 8- to 12-week cold-temperature treatment. Because it's so fast and easy, forcing paperwhites is an excellent project for beginning gardeners. Tip For keeping Paperwhites shorter: Researchers at Cornell University found they could keep paperwhites about 30% shorter than normal by watering them with a 4% to 6% alcohol solution. Paperwhite bulbs grown in water with a 5% concentration of alcohol bloom beautifully on stems 1/3 shorter than paperwhites grown in unspiked water. Most clear liquors are about 40% alcohol (80 proof), so that works out to 1 part liquor to 7 parts water.

Paperwhites get leggy for two reasons. Either they were grown in a room that’s too warm (above 65°F) or they didn’t get enough light. For stocky plants, grow the bulbs in a cool room (50-60°F) and make sure they get lots of bright, indirect light. Once you see buds, move the pot into your living area. Keep the bulbs away from hot sun and heat to extend the bloom time. If the stems do get a bit floppy, use a piece of dental floss to tie them in.