Holiday plant care

Poinsettias, other festive plants need special attention

HEALTHY PLANTS Poinsettias require strong morning sun and afternoon shade. Photo by Kate Russell

Most holiday plants receive too much water and heat, and not enough sunlight, to make it through January. Poinsettias, Amaryllis and miniature Christmas trees make delightful gifts, but they need special care to last.

Poinsettias are fascinating. The bright red blooms are actually modified leaves, called bracts, and the plant is a tree that can reach 13 feet in height. Poinsettias need 12 hours of darkness for at least five days in a row to turn from green to red. Even the slightest exposure to light will halt this process. To keep poinsettias healthy indoors, provide strong morning sun and afternoon shade. Poinsettias can be grown outdoors as long as they are protected from frost. Poinsettias are susceptible to fungal and bacterial diseases that can be prevented by allowing the soil to dry out between waterings. Poinsettias contain latex, which can be an irritant, but they are not poisonous. 

Use these tips to keep your poinsettias healthy: 

• New Year’s Day: Apply all-purpose houseplant fertilizer

• Valentine’s Day: Check for whiteflies; cut down to five inches

• St. Patrick’s Day: Remove dead leaves; add fresh potting soil

• Memorial Day: Cut back three inches; repot, if needed, using fresh potting soil

• Father’s Day: Move outside to a location with indirect light

• Fourth of July: Trim again; move into full sunlight; water and feed, as needed

• Labor Day: Rinse plant off and move it indoors; reduce feeding

• Autumnal Equinox: Place in uninterrupted darkness for 13 hours and bright light for 11 hours each day; nighttime temperatures of 60 degrees are ideal

• Thanksgiving: Reduce water and feeding; place in a sunny window, rotating for full coverage

• Christmas: Enjoy and repeat! 

Most live miniature Christmas trees are Alberta spruce, Italian stone pine or Cypress. Rosemary is also used as a topiary Christmas tree. These plants prefer cooler temperatures, and more sunlight and moisture, than you will find in most homes. Before planting outside, know that Dwarf Alberta spruce will never perform well in high heat, and Colorado blue spruce can reach 75 feet tall. In 20 years or so, a stone pine can provide pine nuts. Rosemary takes care of itself, providing an excellent border or accent in any landscape.

Amaryllis plants are striking South American flowers. They need as much sunlight as you can provide, and temperatures between 68 and 70 degrees. Water sparingly, at first, and then more frequently, allowing the soil to dry out between waterings. Blooms should be removed when they start to wither. Amaryllis produces leaves for most of the year. As leaves turn brown, take them off and move your Amaryllis to a protected area on your patio. Being bulbs, your holiday Amaryllis can last for several years.

Understanding what your holiday plants need to stay healthy can transform them from short-lived hostess tokens to durable members of the landscape or home interior.

Kate Russell is a UCCE Master Gardener in Santa Clara County. For information, visit mgsantaclara.ucanr.edu or call 408.282.3105 between 9:30am-12:30pm, Monday through Friday.

Kate Russell

Kate Russell is a UCCE Master Gardener in Santa Clara county.

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About Kate Russell
Kate Russell is a UCCE Master Gardener in Santa Clara county.