How to care for paperwhite narcissus, and tips for spotting houseplant pests
I am a fan of paperwhite narcissus, though only in small doses, as the fragrance can be overpowering if a room is too small or you have multiple plants.
If purchased as bulbs, paperwhite narcissus can be grown in a pot with growing medium. Your container needs to have a drainage hole in the bottom to avoid soggy soil that causes bulbs to rot. Fill the container with a growing medium appropriate for pots. Leave enough space at the top to allow you to set in the bulbs — pointed end up — on top of the mix. Finish filling the pot with medium while leaving the tips of the bulbs exposed.
It is easier to water the pot if there is a half-inch to an inch gap between the top of the pot and the medium. Space the bulbs close enough that they are almost touching. Check the bulbs frequently and water thoroughly when the potting mix is dry 1 inch below the surface. Do not water more than once a week until the bulbs begin active growth. They perform best in bright light. Add some support if the foliage starts to flop.
The winter season is a good time to focus more on your houseplants. Monitor them for insect problems that often occur when plants become stressed. New houseplants or gift plants can also harbor pests, so inspect them carefully, looking closely at stems and undersides of leaves. You may want to consider isolating new plants before adding them to your collection.
Pests to look out for include:
- Spider mites: Look for webbing in leaf axils, stippled foliage, and weak, off-color leaves. Mites are often difficult to see without a lens.
- Scale: Characteristic sticky, clear honeydew is produced on leaves by these small, immobile, rounded insects that are usually found on stems and veins of leaves.
- Mealybugs: Easy to spot, these insects resemble piles of tiny cotton puffs.
- Whitefly: Whiteflies are a major problem in many greenhouses because they can quickly move to neighboring plants. Look for tiny, white, mothlike insects often found on the undersides of leaves.
- Fungus gnats: The adult black gnats fly around the plant but do no damage. The immature larvae in the moist soil can chew plant roots. They are often a problem in overwatered plants or overly moist flats of seedlings.
• Tim Johnson is director of horticulture at Chicago Botanic Garden, chicagobotanic.org.