March Tips & Events for Santa Clara County
“Spring is sooner recognized by plants than by men." — Chinese Proverb
Spring Garden Market — April 13
Our 28th annual Spring Garden Market will be held on Saturday, April 13 at Martial Cottle Park in San Jose from 9:00 a.m.–2:00 p.m. This is our premier plant sale, sustainable gardening showcase, and vendor fair. We grow varieties not readily available elsewhere, selected for outstanding taste, beauty, and performance in our soil and climate.  More information
Heirloom tomatoes
With all the rain this winter, many plants are growing vigorously. That includes weeds. While some are edible and delicious (purslane, nettles, dandelions), many are a nuisance and compete with your chosen plants for water and nutrients. It helps to stay on top of the situation and remove the weeds before they are able to propagate—for years! It’s less important to know the names of the weeds than to know how they spread. If they propagate by seed, pull or hoe them before they flower and go to seed. If they regrow from roots, pull up as much of the root as possible. Only non-propagating parts are advisable to throw in the compost bin.  Still curious about what’s in your yard? You can identify the weeds through the UC IPM Weed Gallery .

Photo: Nettleleaf goosefoot is among the most common summer annuals, from the UC Integrated Pest Management website
Wet Soil
The clay soils which dominate our area are particularly susceptible to compaction, especially when they have received a lot of rain. These soils are characterized by small mineral particles. Hence squeezing out the air spaces makes it more difficult for plant roots and soil organisms to get the oxygen they need to flourish. Try to avoid walking on or using heavy equipment on soil that is wet. Digging in wet soil can also destroy the structure, breaking up useful soil aggregates and earthworm tunnels. Try to wait until the soil is moist, not wet or dry, for easiest tillage. If you must walk or stand on the soil, use a board to distribute your weight over a broader area. Mulch can also create a bit of a cushion and help minimize compaction.

Photo: Finely textured wet soil, UC, by Jack Kelly Clark
Yellowjackets are beneficial because they prey on plant-feeding insects. Yet they can also be a pest and interfere with human activities. Many are ground-dwelling, while others can nest in protected cavities in buildings. Early spring is when queens emerge in search of a new nesting site. A single reproductive female will start a colony that will number in the thousands. A lure trap can catch a female and prevent a colony from forming in the first place, or it can reduce the population of workers in existing colonies. You can also make a homemade trap by hanging a piece of meat above a bucket of soapy water in which the yellowjackets can drown.

Photo: Adult western yellowjacket, UC, by Jack Kelly Clark
If you have finished cutting the flowers from your daffodils, don’t remove any more of the plant right now. Leave the foliage in place until it completely dies back. This will give energy to the bulbs for next year’s blooms. If the plants have been in the ground for a few years and are starting to get crowded, it is time to separate them. Carefully dig up clumps of bulbs with plenty of soil around them, gently separate the bulbs, and replant them over a larger area. Water them in immediately to help reduce the shock of transplanting them. 

Daffodil FAQs , from the American Daffodil Society

Photo: King Alfred daffodils, UC, by Jack Kelly Clark
Root Crops
Now is a good time to plant root crops. These are plants that are cultivated for the food value of their roots. Included are carrots, beets, radishes, turnips, rutabagas, and parsnips. They do well while it is still cool, before the soil has warmed enough to germinate seeds of warm season vegetables. As a rule of thumb, plant seeds two to three times as deep as the diameter of the seed. Loose soil will allow the roots to grow into their intended shapes, whether round or long and straight. Water right after planting, and keep them moist until they start to grow, either with rainwater or with irrigation. 

Wondering when to plant? See our Vegetable Planting Guide

Photo: Fresh beets, UC, by Evett Kilmartin
Visit or subscribe to our blog  for longer articles on seasonal topics
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!

Sat, Mar 02, 10:00 a.m.–12:00 p.m.,  Gardening in Containers , The Forge Garden, 1051 Sherman St.,  Santa Clara

Sat, Mar 02, 10:00 a.m.–11:00 a.m.,  Irrigation; Review-Restart-Renovate , Palo Alto Demonstration Garden, 851 Center Drive,  Palo Alto

Sat, Mar 02, 1:00 p.m.–2:30 p.m.,  Spring Gardening Tips and To Do lists , Central Park Library, 2635 Homestead Rd,  Santa Clara

Mon, Mar 04, 7:00 p.m.–8:30 p.m.,  Growing Tomatoes Successfully , Morgan Hill Library, 600 W. Main Ave,  Morgan Hill

Tue, Mar 05, 7:00 p.m.–9:00 p.m.,  Gardener's To-Do List for Spring , Saratoga Public Library, 13650 Saratoga Ave,  Saratoga

Wed, Mar 06, 7:00 p.m.–8:30 p.m.,  Soil and Compost: the Foundation of Good Gardening , Cupertino Community Hall, 10350 Torre Ave,  Cupertino

Sat, Mar 09, 10:30 a.m.–12:00 p.m.,  Creating Outdoor Succulent Designs in Containers , Martial Cottle Park, 5283 Snell Ave,  San Jose

Sat, Mar 09, 2:00 p.m.–4:00 p.m.,  Protecting your home and garden from critters , Sunnyvale Public Library, 665 W Olive Ave,  Sunnyvale

Tue, Mar 12, 7:00 p.m.–8:30 p.m.,  Growing Warm Season Vegetables in your Garden  , Gilroy Library, 350 W. 6th Street,  Gilroy

Thu, Mar 14, 7:00 p.m.–8:30 p.m.,  California Native Allstars , Cupertino Library, 10800 Torre Ave,  Cupertino

Sat, Mar 16, 10:00 a.m.–11:30 a.m.,  Building Healthy Soil for Home Garden , St. Louise Hospital Teaching & Demo Garden, 9400 No Name Uno Way,  Gilroy

Sat, Mar 16, 10:30 a.m.–12:00 p.m.,  Planting Citrus Trees in Your Yard , Martial Cottle Park, 5283 Snell Ave,  San Jose

Sat, Mar 16, 11:00 a.m.–12:30 p.m.,  The Monarch Butterfly Crisis: What's Happening and How You Can Help , Berryessa Public Library, 3355 Noble Ave,  San Jose

Wed, Mar 20, 7:00 p.m.–8:30 p.m.,  Growing Summer Vegetables , Milpitas Library, 160 N Main Street,  Milpitas

Sat, Mar 23, 3:00 p.m.–4:00 p.m.,  The Monarch Butterfly Crisis: What's Happening and How You Can Help , Willow Glen Public Library, 1157 Minnesota Ave,  San Jose

Wed, Mar 27, 6:30 p.m.–8:00 p.m.,  From Seed to Plant: Preparing Your Bountiful Garden , Calabazas Library, 1230 S. Blaney Ave,  San Jose

Wed, Mar 27, 7:00 p.m.–8:30 p.m.,  Spring Forward With Tomatoes , Los Altos Library, 13 S. San Antonio Rd,  Los Altos

Wed, Apr 03, 6:00 p.m.–7:30 p.m.,  Winning the War on Weeds , Los Gatos Library, 100 Villa Ave,  Los Gatos

Sat, Apr 13, 9:00 a.m.–2:00 p.m.,  Spring Garden Market , Martial Cottle Park, 5283 Snell Ave,  San Jose
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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