May Tips & Events for Santa Clara County
The garden suggests there might be a place where we can meet nature halfway. — Michael Pollan
Last Chance!
Master Gardener Application Sign Up
May 31  is the deadline for signing up to receive information about becoming a Master Gardener. There’s no commitment at this point, so consider signing up even if you're not yet sure. Visit our website to  learn about the application process

We are a group of passionate gardeners who enjoy educating the public with solid, science-based research from UC. We're looking for enthusiastic candidates to join us. Maybe that’s you!
Help Desk at 2018 Spring Garden Market-Photo Tuan Hoang
Help Desk table at our 2018 Spring Garden Market. Photo: Tuan Hoang
Martial Cottle Park Spring Celebration
Join us Saturday, May 5, 10:00 a.m.–3:00 p.m. for a Spring Celebration at Martial Cottle Park in San Jose. Experience Santa Clara Valley's agricultural past, present and future, on land the Cottle family farmed for over 150 years. We will host gardening talks at our Master Gardener parcel, have children’s activities, and offer seedlings and succulents for sale. 
Seedlings in shade house at Martial Cottle Park-By Allen Buchinski
Acclimating Plants
After starting plants indoors without sun and wind, gradually introduce them to harsher outdoor conditions. This process is called “hardening off”. Put the plants outdoors for a short time the first day, perhaps with indirect or dappled sunlight. Then lengthen their outdoor exposure time over the course of a week or two before transplanting them. If you buy plants from a nursery where they are semi-protected, it’s still a good idea to set the pots in the garden for a few days before transplanting them into the soil. This reduces stress on plants by not changing too many conditions at once.

Photo: seedlings growing in a protected shade house at Martial Cottle Park
Peach leaf curl symptoms
Peach Leaf Curl
Anybody have a peach or nectarine tree without peach leaf curl ? Thought not! This common fungal disease causes leaves to curl, pucker, and turn blotchy red in the spring. (In Spanish it is aptly named lepra de durazno, as in leprosy.) While it may be tempting to pick off all the affected leaves, many of them will fall naturally and be replaced with a second set of healthier leaves. Remove any leaves that have died and any fruit with signs of damage. Then make a note on your calendar to spray with a copper fungicide next winter when the tree goes dormant. Or look for a resistant variety.

Photo: UC, by Jack Kelly Clark
Vegetable seedling freshly planted among mulch and drip irrigation. Photo by Britta Hansen
Efficient Watering
Plants take up water and water-soluble nutrients through their roots, target watering to the root zone. Overhead watering with sprinklers may work for lawns and other groundcovers, but it can waste much water to evaporation or wind drift. Drip irrigation is one way to efficiently water individual plants. For small and shallow-rooted plants, water more frequently and for short periods of time. For large and deep-rooted plants like trees, give infrequent long slow drinks to allow water to penetrate down a couple feet. Depending on the plant water requirements, soil type, and weather, watering schedules can vary from every couple days to once a month. Well-established California native plants or mature trees might not need any extra water.

UC Publication 21579, Drip Irrigation in the Home Landscape is available for $7.00 through the ANR online catalog.

Photo: Vegetable seedling freshly planted among mulch and drip irrigation, Photo by Britta Hansen, UC Davis Feed the Future website .
Basil-photo from University of Illinois Extension website
Herbs are great to have growing in your garden or on your kitchen counter for convenience, aroma, and last-minute cooking ideas. You can just cut what you need and not pay for what you don’t. You can grow thyme for snipping a little, basil for making large batches of pesto, oregano for drying, or rosemary for year-round garnish and flavoring. Planting and care vary widely according to life cycle (annual, biennial, or perennial), sun requirements, and hardiness. Most can be started now from seed, transplants, or cuttings. The flowers of many herbs (e.g., cilantro, African blue basil, lavender) attract bees and ladybugs to the garden to help pollinate flowers and control pests. 

Herb Gardening , University of Illinois Extension
A western tussock moth caterpillar crawls along a plant feasting on its leaves. Credit-Moria Robinson UC Davis
Caterpillars Moving In
The western tussock moth caterpillar infestation is worse this year than previous years. The northern end of our county is being hit particularly hard (as reported by the Mountain View Voice ). The larvae chew leaves and can quickly defoliate a tree. Bacillus thuringiensis (Bt) is a bacterium that can be sprayed as an organic control. There's also a parasitic wasp that is a natural enemy. The adults are seen later in the spring. The male moths are brown and gray and triangular shaped. The females are grayish-white and wingless and can lay up to 300 eggs. 

Image: A western tussock moth caterpillar crawls along a plant, feasting on its leaves. Moria Robinson/UC Davis, UC Davis College of Agricultural and Environmental Sciences
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Upcoming Events
We offer lots of 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!

Photo: drip irrigation workshop at Martial Cottle Park.

Palo Alto Demo Garden Now Open Saturdays from 10 a.m.–noon (May–Oct)
Come see what we're growing at our edible and water wise gardens and get answers to your gardening questions. Feel free to bring plant pests or disease samples for identification. We're located at Eleanor Pardee Community Gardens, on Center Road near Martin Street (v iew map ).

 Wed, May 02, 7:00 p.m.–8:30 p.m.,  Container Gardening , Cupertino Community Hall, 10350 Torre Ave,  Cupertino

Sat, May 05, 10:00 a.m.–3:00 p.m.,  Martial Cottle Park Spring Celebration , Martial Cottle Park, 5283 Snell Ave,  San Jose

Sat, May 05, 10:30 a.m.–11:30 a.m.,  Good Bugs / Bad Bugs: Recognizing and Attracting Beneficial Insects to the Garden , Martial Cottle Park, UC Master Gardener Parcel in the Teaching Pavilion, 5283 Snell Ave San Jose, CA 95136,  San Jose

Sat, May 05, 11:00 a.m.–12:30 p.m.,  Creating a Habitat Garden , Martial Cottle Park, UC Master Gardener Parcel in the Teaching Pavilion, 5283 Snell Ave,  San Jose

Sat, May 05, 12:30 p.m.–1:30 p.m.,  Drip Irrigation for Your Garden , Martial Cottle Park, UC Master Gardener Parcel in the Teaching Pavilion, 5283 Snell Ave,  San Jose

Mon, May 07, 7:00 p.m.–8:30 p.m.,  Basics of Growing Orchids , Morgan Hill Library, 60 W Main Ave,  Morgan Hill

Wed, May 09, 7:00 p.m.–8:30 p.m.,  Creating a Children’s Garden , Gilroy Library, 350 W 6th St.,  Gilroy

Wed, May 16, 6:30 p.m.–8:00 p.m.,  Culinary Herbs , West Valley Branch Library, 1243 San Tomas Aquino Rd.,  San Jose

Wed, May 16, 7:00 p.m.–8:30 p.m.,  Attracting Pollinators to Your Gardens , Milpitas Library, 160 North Main Street,  Milpitas

Sat, May 19, 10:00 a.m.–12:00 p.m.,  Planting Beneficial Plants to Attract Pollinators to your Garden , St. Louise Hospital Teaching & Demo Garden, 9400 No Name Uno Way,  Gilroy

Sat, May 19, 11:00 a.m.–12:00 p.m.,  Growing Citrus in Containers , Martial Cottle Park, UC Master Gardener Parcel in the Teaching Pavilion, 5283 Snell Ave,  San Jose

Sat, May 19, 1:00 p.m.–2:30 p.m.,  Container Gardening , Central Park Library, 2635 Homestead Rd.,  Santa Clara

Sat, May 19, 1:00 p.m.–3:00 p.m.,  Organic Vegetable Gardening for the Home Gardener , Sunnyvale Teaching and Demonstration Garden, Charles Street Gardens, 433 Charles St.,  Sunnyvale

Wed, May 30, 7:00 p.m.–8:30 p.m.,  Don't Squash that Bug! Recognizing Beneficial Insects in the Garden , Los Altos 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 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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