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January Tips & Events for Santa Clara County
“Rainy days were invented so that gardeners could get the housework done.”
— Author unknown
Selecting Seeds
While curled up inside the warm, dry house poring through seed catalogs, how do you decide among all the delightful descriptions? First be clear on the purpose of your garden. Are you trying to grow exotic food? Do you want to attract native butterflies? Are you interested in flowers you can cut and bring inside? Next think about the conditions of your site. Is it warm and sunny or is there a lot of shade? Do you have heavy clay soil? Choosing seeds that do well in your area makes for healthier plants with less work. At this point you have the parameters within which to choose what tickles your fancy. If you would like to save seeds in the future, then choose open-pollinated seeds, including heirlooms. Heirlooms are open-pollinated seeds that have been around for multiple generations. Otherwise you can plant hybrids which have the best traits of their parent plants but will not reproduce true to type from saved seeds. Follow planting directions on the packet for best results.

More Information: Seed Saving

Photo: Illustrated Seed Structure, California Master Gardener Handbook
Certified Arborist
Whether you prune your own trees or hire someone, it’s important that whoever does the job knows at least a little about tree anatomy, plant health, and the purpose of the plant (shade? privacy? fruit?). Knowing the difference between heading cuts and thinning cuts, how to locate a node to direct growth, and how to open up a tree for air circulation are all part of good tree pruning. An improper pruning job can stress the tree, spread disease, invite pests, and promote weak branching. These can lead to breakage, damage, and injury. The cheapest bid may end up costing more in the long run due to damage repair, lawsuits, and additional fix-it pruning. Take a class or read tree pruning guides if you want to do a good job yourself. If you hire someone, it is strongly recommended that you choose a certified arborist who has been specially trained and is insured. The International Society of Arboriculture can help you find a certified arborist in your area.

More Information: Tree Pruning Guide

Photo: Professional Tree Pruning, by Jack Kelly Clark
Photo by Laura Monczynski
Flowering Vines
Vines are plants that climb or sprawl and can easily outgrow their spaces if not pruned annually or more often. Many are pruned in the winter when they are dormant. This reduces shock to the plant and allows you to better see the structure when pruning. If the vines are flowering, wait until after the blooms have finished. Some vines get cut back almost to the ground to renew them. Some are cut back to the beginning of the herbaceous growth, leaving the woody vines. Others are pruned simply for shape or size. The UC Davis Arboretum All-Stars brochure includes several flowering vines. All-Stars are plants that have been tested and proven to thrive in California. The brochure lists pruning needs. It also has photos, characteristics, and requirements of the plants if you are looking for new plants.  

More Information: Marin Master Gardeners: Vines

Photo: Flowering vines still in bloom, by Laura Monczynski
Bareroot roses
Bare Root Roses
This month and next are ideal for planting bare root roses. When you choose roses, the American Rose Society can help you navigate the 150 species and thousands of hybrids. Besides color and growth form, you may also consider the balance between scent and appearance. Many of the older roses are highly fragrant, while many newer roses are bred for beauty and large blooms. Consider the susceptibility of roses to many diseases when choosing a spot in your garden. They do best with six hours of sun, in well-drained soil, with good air circulation, and without overhead watering. When planting, mix organic material with native soil in the planting hole. Make sure the base of the plant remains an inch or two above the surrounding soil so that water doesn’t accumulate around the crown. Water thoroughly immediately after planting.  

Photo: Groundcover Roses, by John F. Karlik, UCCE Kern County
Armillaria Root Rot
This fungal infection, sometimes called oak root fungus, can affect a variety of ornamental and fruit trees. Its presence can remain undetected underground for years and it stays in both live and decaying roots. It can travel from one plant to another and it thrives in wet conditions. The fruiting bodies (mushrooms) may appear at the base of the trunk and alert you to the problem. It is notoriously hard to control. Temporarily moving the soil away from the base of the tree and allowing the crown to dry may help save the tree. Before putting in new plants, remove as much infected plant material as possible and air-dry the soil. Choose resistant species or plants that are not known as hosts of Armillaria to help control the fungus.

More Information: Armillaria management

Photo: Evidence of Armillaria on an apple tree, by Susan Casner-Kay

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Class at Martial Cottle Park by Tuan Hoang
Upcoming Events
We offer free or low-cost gardening talks, workshops, and courses all over the county, as well as hosting information tables at many community events. Please join us and bring your questions!

Mon, Jan 06, 7:00 p.m.–8:30 p.m., Basics of Growing Orchids , Morgan Hill Library, 60 West Main Ave, Morgan Hill

Tue, Jan 07, 7:00 p.m.–8:30 p.m., Winter Fruit Tree Care and Selection , Gilroy Library, 350 W. 6th St., Gilroy

Wed, Jan 08, 7:00 p.m.–8:30 p.m., Winter Care of Roses , Cupertino Library, 10800 Torre Ave, Cupertino

Thu, Jan 09, 6:00 p.m.–8:00 p.m., Gardening Mentors Needed! , Sacred Heart Community Services, 1381 South First Street, San Jose

Sat, Jan 11, 10:00 a.m.–11:30 a.m., Fruit Tree Pruning Workshop , St. Louise Hospital Teaching & Demonstration Garden, 9400 No Name Uno Way, Gilroy

Sat, Jan 11, 2:00 p.m.–4:00 p.m., Growing Shade-loving Plants in the Garden , Sunnyvale Public Library, 665 W Olive Ave, Sunnyvale

Tue, Jan 14, 7:00 p.m.–8:30 p.m., Winter Fruit Tree Pruning , Campbell Library, 77 Harrison Ave, Campbell

Sat, Jan 18, 11:00 a.m.–12:30 p.m., Fruit Tree Selection and Care , Berryessa Library, 3355 Noble Ave, San Jose

Sat, Jan 18, 1:00 p.m.–2:30 p.m., Get Your Garden Ready for Spring Time , Santa Clara Library, 2635 Homestead Rd, Santa Clara

Sat, Jan 25, 10:00 a.m.–12:00 p.m., Beginning Gardening: 3 Week Course ($50 SJ Residents, $55 Non SJ Residents), Camden Community Center, 3369 Union Ave, San Jose

Sat, Jan 25, 2:00 p.m.–3:30 p.m., National Seed Swap Day , Santa Clara Teen Center, 2446 Cabrillo Ave, Santa Clara

Mon, Jan 27, 7:00 p.m.–9:00 p.m., Sustainable Vegetable Gardening , FUHSD (Sunnyvale-Cupertino), Adult School Vallco Main Campus, 10123 North Wolfe Road, Cupertino

Wed, Jan 29, 7:00 p.m.–8:30 p.m., Winter Rose Care , Los Altos Library, 13 S. San Antonio Rd, Los Altos

Sat, Feb 01, 10:00 a.m.–12:00 p.m., Winter Fruit Tree Care , Everett N. “Eddie” Souza Park, 2380 Monroe St., Santa Clara

Wed, Feb 12, 7:00 p.m.–8:30 p.m., Spring Garden Tips and To Do , Los Altos Public Library, 13 S. San Antonio Rd, Los Altos
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 Help Desk (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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