May Tips & Events for Santa Clara County
“Gardening is the art that uses flowers and plants as paint, and the soil and sky as canvas." — Elizabeth Murray
From UC Davis Project Compost
Soil Amendments
Do you really need to amend your soil? It all depends on the condition of the soil and what is being planted there. California native plants have evolved in our native soils and grow best in soil left in its natural state. For trees, little if any amending of the planting hole is needed or even desired. Trees put down deep roots well beyond the original planting hole, and it’s harder for roots and water to move from one soil type to another. Quick-growing vegetables and flowers do best in loose, amended soil. Include fertilizer to replace the nutrients that are taken away in plant parts that you eat or put into a vase. Compost and specialized planting mixes are good soil amendments.

Nurture the Soil , UC Davis Central Valley Friendly Landscaping

Photo: UC Davis Project Compost Why Compost?
Sunflowers by Laura Monczynski
Not all sunflowers are tall. They come in a wide variety of heights, from a couple feet to twenty feet tall. While most are yellow, some are orange or even red. They can easily be started from seed and are not fussy. They will need water to get started, but not much once they mature. Sunflowers are known for turning during the day to face the sun. This movement in response to the sun is called heliotropism. You may find, however, that they end up mostly facing east. Keep the direction in mind when choosing where to plant them. You may attract birds and squirrels to your garden with the seeds, yet they may enjoy the sunflowers so much that they don’t bother your other edibles.

Photo by Laura Monczynski
Lani aerator from UC ANR Repository
Aerate Lawns
Our Santa Clara County clay soil with its small particles and small pore spaces can easily get compacted, especially when walked on when wet. Year-round lawn mowing can really squeeze the air spaces out of the soil. This makes it hard for roots to penetrate and for water, air, fertilizer, and soil organisms to travel down through the soil. To correct this, aerate your lawn. You can use a hand tool, a machine, or you can hire someone to do it. Use a method that pulls cores out of the ground. You can then rake up the cores or leave them in place as a topdressing. Avoid spike methods they will make holes in the soil but will further compact the soil around the holes.

Aerating , UC Guide to Healthy Lawns

Photo: metal tines of an aerator remove small cores of soil, UC Repository, by Stephen E. Lock
Master Food Preservers San Bernardino County
The soil is starting to warm up, so you can plant melons from seed outdoors or in containers for later transplant. The former avoids transplant shock and the latter gives them a head start and reduces vulnerability to pests. Having originated mostly in Africa, melons are best suited to warm, sunny conditions. Plant them in loose, well-drained soil, and water regularly to keep the soil evenly moist. Once the melons form, keep them off the ground so that they will not easily rot or be damaged by soil-dwelling pests. You can prop the fruits up on something like a cat food can, or you can grow the vines up a trellis. Hold heavy melons that hang down in place by making a sling out of stockings or another light stretchy material.

Photo: Cantaloupe and honeydew melon slices , Master Food Preservers, San Bernardino County
From Laura Monczynski
Hibiscus flowers are used to make the agua de jamaica drink in Mexican restaurants. You can have a taste of the islands in your own yard by planting hibiscus. We most often see the vibrant red flowers, yet there is a lot of variety in the hibiscus genus. And sometimes a different color will eventually revert to red. Hibiscus are tropical so they may need a little protection on those few cold nights we get most years. If possible, plant them under an overhang or close to the warm house. Be prepared to deal with the giant whitefly pest. This pest appears on the undersides of leaves, makes what looks like a white beard hanging down from the leaves, and sucks the juices from the plant. Use a strong jet of water as often as needed to wash the insects off the plant and help keep them under control. 

Hibiscus , UC Integrated Pest Management

Photo by Laura Monczynski
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 Ask a Master Gardener Booth 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!

Wed, May 01, 7:00 p.m.–8:30 p.m.,  Monarch Butterflies - What is Happening & How to Help , Cupertino Community Hall, 10350 Torre Ave,  Cupertino

Sat, May 04, 10:00 a.m.–11:30 a.m.,  Growing Warm Season Vegetables , The Forge Garden, 1051 Sherman St.,  Santa Clara

Sat, May 04, 10:00 a.m.–4:00 p.m.,  Going Native Garden Tour , Santa Clara County South

Sat, May 04, 10:00 a.m.–11:00 a.m.,  Ready, Set, Go for Summer Gardening , Palo Alto Demonstration Garden, 851 Center Dr.,  Palo Alto

Sun, May 05, 10:00 a.m.–4:00 p.m.,  Going Native Garden Tour , Santa Clara County North

Mon, May 06, 7:00 p.m.–8:30 p.m.,  Creating a Children's Garden , Morgan Hill Library, 60 West Main Ave,  Morgan Hill

Sat, May 11, 3:00 p.m.–4:00 p.m.,  Growing Vegetables in Containers , Willow Glen Public Library, 1157 Minnesota Ave,  San Jose

Tue, May 14, 7:00 p.m.–8:30 p.m.,  Home Composting , Campbell Library, 77 Harrison Ave,  Campbell

Wed, May 15, 7:00 p.m.–8:30 p.m.,  Culinary Herbs , Milpitas Library, 160 N Main St.,  Milpitas

Sat, May 18, 9:00 a.m.–12:00 p.m.,  Succulents Plant Sale , Martial Cottle Park, 5283 Snell Ave,  San Jose

Sat, May 18, 10:00 a.m.–11:30 a.m.,  Care of California Native Plants , St. Louise Hospital Teaching & Demo Garden, 9400 No Name Uno Way,  Gilroy

Sat, May 18, 10:30 a.m.–12:00 p.m.,  Drip Irrigation for Your Garden , Martial Cottle Park, 5283 Snell Ave,  San Jose

Sat, May 18, 1:00 p.m.–2:30 p.m.,  Incredible Edibles: Cucumber, Melons, and Squash! , Mission Branch Library, 1098 Lexington St,  Santa Clara

Sat, May 18, 1:00 p.m.–3:00 p.m.,  Growing Shade-loving plants in the Garden , Sunnyvale Teaching and Demonstration Garden, 433 Charles St.,  Sunnyvale

Wed, May 22, 6:30 p.m.–8:00 p.m.,  Know Good Bugs & Bad Bugs in Your Garden , Calabazas Library, 1230 S. Blaney Ave,  San Jose

Wed, May 29, 7:00 p.m.–8:30 p.m.,  Attracting Pollinators to Your Gardens , Los Altos Library, 13 S. San Antonio Road,  Los Altos

Sun, Jun 02, 11:00 a.m.–12:00 p.m.,  A Kid’s Exploratory Event: Using your Senses in the Garden  , Palo Alto Demonstration Garden, 851 Center Dr.,  Palo Alto
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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