December Tips & Events for Santa Clara County
"Gardening gives one back a sense of proportion about everything — except itself.”  May Sarton
Mosquito larvae in water - Photo UC IPM Jack Kelly Clark
Standing Water
Now that it’s starting to rain, go all around your yard and turn over or put away any pots, trays, or buckets that could get rained in. Standing water can be a breeding ground for mosquitos which can carry West Nile Virus and other diseases. A female mosquito can lay over a hundred eggs at a time!

Photo: mosquito larvae in standing water, UC IPM, Jack Kelly Clark
Above ground plastic water tank
Rain Water Collection
If you want to collect rainwater for later use in irrigation, you can install a catchment system. Rain barrels and cisterns commonly range in size from 55 gallons to 10,000 gallons, depending on the surface area of your roof, the storage space available in your yard, and your intended uses for the water. Or consider a rain garden to prevent water from flowing down storm drains.

Photo: above ground plastic water tank
Pruning Grape Vines
Grapes vines can be pruned once the leaves fall off. Make sure you pull off any remaining fruit mummies or raisins. You can choose cane pruning or spur pruning, depending on the grape variety. The goal is to have fruiting spurs well-spaced so grape clusters can grow with good air circulation around each cluster.

Garden cyclamen
Cyclamen do well with cooler temperatures and provide color in the garden in December. They do best with partial shade or with early morning or late afternoon sun. Water needs are minimal and it is important for them to have good drainage. They can live for several years. Cyclamen can thrive both outdoors and indoors, although be sure to let them dry out between waterings when inside.

Bare Root Roses
When choosing bare root roses, look for healthy, strong canes, as opposed to dry or brittle ones. The roots should be light colored and firm. Spread the roots out when putting the plant in the ground to keep them from circling later. Make sure the rose is planted slightly above the surrounding soil. This prevents standing water at the base of the plant from contributing to crown rot.

Photo: Tamora English rose
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Upcoming Events
Sat, Dec 02, 10:00 a.m.–noon,  Annual Wreath Making Workshop , Guadalupe River Park Conservancy, 438 Coleman Ave,  San Jose

Sat, Jan 06, 2:00–4:00 p.m.,  Backyard Deciduous Fruit Tree Basics , Sunnyvale Public Library, 665 West Olive Avenue,  Sunnyvale

Wed, Jan 17, 7:00–8:30 p.m.,  Growing Fabulous Citrus , Milpitas Library, 160 North Main Street,  Milpitas

Sat, Jan 20, 11:00 a.m.–12:30 p.m.,  Winter Fruit Tree Pruning , Berryessa Library, 3355 Noble Ave, San Jose

Wed, Jan 31, 7:00 p.m.–8:30 p.m.,  Winter Fruit Tree Pruning , Cupertino Community Hall, 10350 Torre Ave.,  Cupertino
Visit the UC Master Gardener Program website  for additional information including an up-to-date list of events and classes .

Have a gardening question? Contact our Hotline (for Santa Clara County residents). Start by reviewing our plant  problem diagnosis tips .
  • Mon-Fri 9:30 a.m.–12:30 p.m., 408-282-3105
  • Fri ONLY 1:00 p.m.–4:00 p.m., 650-329-1356 (Closed Dec. & Jan.)
  • Or send us your question online

The University of California Cooperative Extension (UCCE) Santa Clara County Master Gardener Program volunteers are trained under the auspices of the UCCE. Our mission is to promote sustainable gardening practices by providing up-to-date, research-based horticultural information to home gardeners.

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