By Cindy Watter, UC Master Gardener of Napa County
Amaryllis is a popular Christmas gift and decoration. I have received many over the years, and they are long lasting and beautiful. However, they are not true amaryllis. The most familiar true amaryllis (Amaryllis belladonna) is a South American native that grows all over California and is known by many as “naked lady.”
The Christmas amaryllis is a South African native, Hippeastrum, a name derived from the Greek, meaning “mounted knight's star.” The bloom is indeed star-shaped, at the end of a hollow stalk, with flat straplike, single-ribbed leaves. For this article I will refer to it as amaryllis, however.
The amaryllis is a popular plant because it can be forced: that is, it can be made to bloom outside of its natural growing season. That's why it is so valued. For those of us living in California, winter is not that bleak, but in December in the northeast people welcome that spot of color. The U.S. imports more than 10 million amaryllis bulbs annually, mostly from South Africa and Holland.
Many people receive an amaryllis for Christmas and don't know what to do with it when it stops blooming and begins to shrivel. First, don't worry—it only looks dead. It is really entering another stage of life.
When the flowers fade, cut them off so they don't produce seeds. (Seed formation will use up energy reserves in the bulb.) When the flower stalk turns yellow, use pruners to cut the stalk to a couple of inches above the bulb. Leave the leaves alone—they help produce food for the plant. Put it where it will get sunlight—a window ledge indoors is ideal—and water it when the surface looks dry. Feed it with a half-strength fertilizer high in phosphorus. Your local nursery can recommend one.
But wait—what if someone gave you an amaryllis bulb that is covered in colored wax and not in a pot? Just trim off the wax and put it in a pot. Wait until it stops blooming before you do that, of course.
The next stage is hardening off. That's the term for gradually transitioning a plant from a cozy indoor existence to more challenging conditions outdoors. In late spring, move your amaryllis outdoors, putting it first in a shady, protected area for a few days. Then, gradually, expose the plant to more sun. After 10 days or so, the plant can remain in full sun.
Keep watering the amaryllis—don't let it dry out. Fertilize it once or twice a month. It will produce lots of green leaves. Bring it indoors in September if you want it to flower in December. Continue watering and feeding it.
To get a bloom in winter, commercial growers first put the plants in a dormant state, starting in fall. They place the plants in a 50°F to 55°F setting away from sunlight. (Home cultivators put the bulbs in a closet or basement.) The growers cut off fertilizer and don't water the plants. The leaves turn brown and are trimmed off.
After at least two months in the dark, the plant is moved to a sunny setting and watered regularly to keep the soil moist. It will rebloom in winter. When the buds appear, the amaryllis is transferred from direct sunlight to indirect light.
In our Napa Valley climate, you can just leave your amaryllis outside unless frost threatens. After two to three months in a shady place, move it indoors to a sunny location and keep the soil moist. It should bloom again.
An amaryllis bulb, properly cared for, can last for seventy-five years. Note: The bulb is toxic; the flowers and leaves aren't.
I used to get Christmas amaryllis as gifts from students. I followed the guidelines for keeping them alive past the holidays, and in spring I put them outdoors in dappled sun. I am not organized enough to follow a precise regimen of light deprivation. In any case, I don't have an extra closet for inducing dormancy, so my flowers reappeared in the summer.
If you plant your amaryllis directly in the ground, use a little bone meal and make sure the bulb necks are level with the soil surface. Be on the alert for slugs.
The Christmas amaryllis is a lovely flower that can be quite showy. Some of them produce as many as 14 blooms. They have been bred to blossom in red for the holidays, but they come in all hues. The amaryllis is a joyful way to greet the new year.
Library Talk: Join UC Master Gardeners of Napa County for a Napa Library talk on “Growing Peppers” on Thursday, January 2, from 7 pm to 8 pm via Zoom. Let's parlez peppers—hot, sweet and mild. Learn the basics of starting peppers from seed, plus growing tips and usage ideas for your eventual harvest. Click here to register!
Rose Pruning Workshop: Join UC Master Gardeners of Napa County for a workshop on “Winter Rose Care” on Saturday, January 11, from 10 a.m. to noon, via Zoom. Learn pruning techniques for all types of roses along with everything you need to know to make your roses a success in 2025. Attendees will be invited to a hands-on pruning workshop at Fuller Park Rose Garden on January 18 to practice what they learned. Register here.
QWEL Training: Napa County landscape and irrigation pros are encouraged to become Qualified Water Efficient Landscapers (QWEL). Earn this EPA WaterSense award-winning professional certification and save water and money for clients. The City of Napa is sponsoring free in-person QWEL training in English on four Wednesdays starting January 15. Space is limited. Register at qwel.net/pub/class/491.
Help Desk: The Master Gardener Help Desk is available to answer your garden questions on Mondays and Fridays from 10 am until 1 pm at the University of California Cooperative Extension Office, 1710 Soscol Avenue, Suite 4, Napa. Or send your questions to mastergardeners@countyofnapa.org. Include your name, address, phone number and a brief description of the problem.
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