April Tips & Events for Santa Clara County

“I love spring anywhere, but if I could choose I would always greet it in a garden.”

~ Ruth Stout

Monthly Tips

Quiz: What Are These?

While working outside, you might spot something like this on a dead leaf. Have you seen them in your yard? Do you know what they are?

Photo credit: Ying Chen

A dead leaf covered with many small, round objects

The front yard of a home filled with blooming shrubs and plants bordering a brick pathway

Photo credit: Saxon Holt

Growing Natives Tour

Growing Natives Garden Tour

If you’re considering adding native plants to your landscape, you’ll find inspiration by attending the free Growing Natives Garden Tour on April 12 and 13. Organized by the California Native Plant Society and the UC Master Gardeners of Santa Clara County and San Mateo and San Francisco Counties, the tour will feature over 50 home and public landscapes. You’ll learn how native plants are not only attractive but also save water, provide homes for birds and pollinators, and make your garden more resilient to the extremes of climate change. It’s a great time to see California natives in bloom.

Amending Soil for Vegetable Gardens

How you amend your soil for a vegetable garden depends on your garden. Adding organic matter such as compost helps loosen clay soils and build up sandy soils. If your soil is already rich in organic matter, you may not need to add much more. In addition, vegetables need fertilizer, especially nitrogen, which gets used up or washed out of the soil, so we need to add some every time we plant. Other nutrients, such as potassium and phosphorus, are generally abundant in Santa Clara County soils, so a fertilizer that is primarily nitrogen is a good choice. See Vegetable Gardening Basics for more details.

Photo credit: Canva

Vegetable Gardening Basics

Spring Garden Fair!

Two women carefully placing seeds into a tray of soil

We’re planting and potting up seedlings, developing talks, readying booths, and organizing all aspects of our Spring Garden Fair—just for you! Join us on April 26 from 9:00 am to 2:00 pm at Martial Cottle Park. This event will showcase summer gardening with engaging talks and demonstrations. Enjoy our seed swap, repairs at the Repair Café, and botanical drinks at the garden-to-glass booth. Shop unique finds at the Green Elephant and explore the One World Kitchen Garden. And don’t miss our big plant sale, featuring tomatoes, peppers, herbs, ornamentals, succulents, and native plants. We’ve been hard at work preparing for you!

Photo credit: Rhonda King-Curry

Spring Garden Fair

We Want Your Opinion

Tomato Sart Roloise, a yellow tomato with burgundy streaks

Help us test three exciting new tomatoes in your garden and share your results. Tomatoes Green Doctors, Queen of the Night, and Sart Roloise were all standouts in our internal tastings last summer, and now we want to see how they perform in home gardens across the county. By growing the same varieties in diverse conditions, we can better identify top-performing tomatoes to offer in the future. Seedlings will be available for purchase at our Spring Garden Fair—visit the Tomato Trial Booth to get yours and be part of the experiment!

Photo: Tomato Sart Roloise, Marilyn Becker

Public Tomato Trial

Purple wisteria flowers on vines twining from an arbor

Bloom Now, Prune Later

Prune spring-blooming shrubs right after they finish flowering to encourage healthy growth and maximize blooms next year. These plants, like wisteria, lilacs, camellias, and more, form flower buds in late summer and fall. If you prune too late, you risk cutting off next year’s flowers. In Santa Clara County’s warm climate, this timing also helps plants recover before summer heat. Use clean, sharp tools to remove dead or overgrown branches to improve airflow and plant shape. Timely pruning keeps your shrubs vibrant and full of blooms for seasons to come!

Photo credit: Karen Schaffer

Pruning Trees, Shrubs, and Vines

Quiz Answer: Slime Mold

Surprise! These are not eggs but the fruiting bodies of the insect egg slime mold, Leocarpus fragilis. It comes in a variety of colors ranging from white, tan, and yellow to brilliant orange and burgundy. Slime molds are neither plant, animal, nor fungus but are considered to be part of the kingdom Protista. They start their life as spores. In the presence of water, they germinate into amoeba-like cells. When multiples of these cells combine, they form a blob (plasmodium) that can move through wet soil and vegetation to feed on bacteria, algae, and fungal spores. They help organic materials decompose and are not considered harmful to the garden. Slime molds usually disappear within a week or so.

Round yellow nodules on a plant stem - shown against a black background

Photo: Insect-egg slime (Leocarpus fragilis), Robert Siegel

Mysterious Tiny Eggs

More April Tips and To-Dos

For more gardening tips and to-dos, visit the monthly tips archive on our website. It is perfect for browsing, and while you may recognize some of the content, you’re sure to find something new. It starts with to-dos for the month, just the thing to review before heading out to your garden.

More Tips and To-Dos

Upcoming Events

Our monthly Plant Clinic Online is an opportunity to chat with a Master Gardener via Zoom to diagnose a plant problem. You can also listen and learn while other people ask questions. It takes place on the second Tuesday of the month (April 8) from 7 to 8:30 pm. Priority will be given to questions that are emailed in advance; instructions are in the Zoom registration confirmation. Registration required .

Mark your calendars: our Spring Garden Fair is Saturday, April 26, at Martial Cottle Park!

PADG The Beauty of the Spring Waterwise Garden, April 5 2025, 10:00am–11:15am, Palo Alto Demonstration Garden, 851 Center Drive, Palo Alto

Growing Citrus in your Home Garden, April 5 2025, 10:30am–11:30am, Gilroy Public Library, 350 W 6th Street, Gilroy

Growing Great Tomatoes and Peppers, April 5 2025, 11:00am–12:30pm, Community Room, Berryessa Public Library, 3355 Noble Avenue, San Jose

Growing Vegetables in your Summer Garden, April 8 2025, 5:30pm–6:30pm, Morgan Hill Public Library, 660 West Main Avenue, Morgan Hill

Gardening in Our Changing Climate, April 8 2025, 6:30pm–8:00pm, Online

Building Structures in the Garden,, April 8 2025, 7:00pm–8:00pm, Saratoga, Saratoga Library - Community Room : 13650 Saratoga Ave, Saratoga

Plant Clinic Online, April 8 2025, 7:00pm–8:30pm, Online

Citrus Planting and Care, April 12 2025, 10:00am–11:30am, Guadalupe River Park Historic Orchard, 425 Seymour Street, San Jose

Growing Natives Garden Tour, April 12 2025, 10:00am–4:00pm, Southern part of Santa Clara County

Learn to Successfully Grow Tomatoes, April 12 2025, 10:00am–12:00pm, McClellan Ranch Preserve, 22221 McClellan Road, Cupertino

MCP Guided Tours of the Master Gardeners Native Entrance Gardens, April 12 2025, 10:00am–4:00pm, Martial Cottle Park - Native Entrance Gardens, 5283 Snell Ave, San Jose

Growing Natives Garden Tour, April 13 2025, 10:00am–4:00pm, Northern Santa Clara County & Southern San Mateo County

Low Water Lawn Alternatives, April 16 2025, 7:00pm–8:30pm, Cupertino Library, 10800 Torre Avenue, Cupertino

Myth or Fact? Debunking Pest Myths, April 17 2025, 12:00pm–1:00pm, Online

Planning and Planting a Summer Vegetable Garden, April 19 2025, 10:30am–11:45am, Willow Glan Branch Library, 1157 Minnesota Avenue, San Jose

Gardening in Our Changing Climate, April 19 2025, 11:00am–12:30pm, Milpitas Library, 160 N Main Street, Milpitas

Summer Success with the Big Three: Tomatoes, Peppers and Eggplants, April 19 2025, 1:00pm–3:00pm, Charles Street Gardens, 433 Charles Street, Sunnyvale

Container Gardening, April 22 2025, 6:30pm–8:30pm, Fremont Unified high School District Adult Education, 589 W Fremont Avenue, Sunnyvale

Spring Garden Fair, April 26 2025, 9:00am–2:00pm, Martial Cottle Park, 5283 Snell Avenue, San Jose

Companion Planting: The Three Sisters Method, May 10 2025, 10:00am–12:00pm, McClellan Ranch Preserve, 22221 McClellan Road, Cupertino

The Mystery of Purple Veggies, May 10 2025, 10:30am–11:45am, Willow Glen Public Library, 1157 Minnesota Avenue, San Jose

Check our calendar for the latest schedule of events. Videos of many past presentations are also available.

About Us

University of California Master Gardener volunteers promote sustainable gardening practices and provide research-based horticultural information to home gardeners. Visit our website for more information including:

More Monthly Tips
A complete list of Upcoming Events and Classes
Extensive Garden Help
Videos of garden tips and past online presentations

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