Issue: January 1, 2000

Planting Christmas plants outside in winter

I received many flowering plants for Christmas. Can I plant them outside? How long should I wait to plant them outside? I am afraid I will kill them indoors.

Answer: Some of the plants given for the holidays cannot be planted outdoors, though they may be grown outdoors in their pot through the summer. Other plants are hardy enough to survive outdoor conditions. It depends on your weather and on which plants you have received.

Of those plants commonly given for the Christmas holidays, chrysanthemum, paper white narcissus, tulips, and lilies are good candidates for outdoor planting. However, it would be best to delay until after the worst of winter has past, or until the flowering bulbs have gone dormant.

If it is necessary to plant it outside soon, chrysanthemum plants (once flowering has ended) may be preconditioned by placing them in an area with lower temperatures. At this time, light is not critical, the object is to induce it to become hardy by exposure to low temperatures. Moisture is critical, so don't over water, but don't forget to keep the soil a little moist. After a few weeks, even colder temperatures may be tolerated. By mid-February in Southern parts of New Mexico, it may be planted outside (a month or so later in the northern parts of the state and in the mountains).

The top may freeze, but if the plant is hardened, the crown and roots should survive and begin growing as the weather warms.

The flowering bulb plants (narcissus, tulips, daffodils, and such) may be hardened as described above once the leaves begin to die back. If the soil is not frozen to prevent soil preparation, you may then plant these bulb plants in a well prepared site to which some organic amendments and phosphate fertilizer have been added.

Lilies should be kept until after the cold weather has passed and planted in a well-prepared site as described for the other bulb plants.

Plants such as poinsettia, Christmas cactus, and other tropical plants should not be planted outside. They may be placed outside in their pots over the summer but must not be exposed to freezing, or even near-freezing temperatures.

Marisa Y. Thompson, PhD, is the Extension Horticulture Specialist, in the Department of Extension Plant Sciences at the New Mexico State University Los Lunas Agricultural Science Center, email: desertblooms@nmsu.edu, office: 505-865-7340, ext. 113.

For more gardening information, visit the NMSU Extension Horticulture page at Desert Blooms and the NMSU Horticulture Publications page.

Send gardening questions to Southwest Yard and Garden - Attn: Dr. Marisa Thompson at desertblooms@nmsu.edu, or at the Desert Blooms Facebook.

Please copy your County Extension Agent and indicate your county of residence when you submit your question!