April Tips & Events for Santa Clara County
No occupation is so delightful to me as the culture of the earth, and no culture comparable to that of the garden. ~Thomas Jefferson
Monthly Tips
Quiz: What Is Causing These Leaves to Curl?
When we notice curling leaves on our plants, we often worry that something may be wrong. But before we reach for a spray, we should figure out what is going on. Do you have any ideas about the plants pictured in these photos? Scroll to the bottom to learn more.
Photo credit: 1) Help Desk submission 2) Jack Kelly Clark, UC ANR 3) Jeanette Alosi, Butte County MG 4) Texas Tech University
Help Desk submission-Jack Kelly Clark-UC ANR-Jeanette  Alosi-Butte County MG-Texas Tech University
Spring Garden Fair - Karen Schaffer
The Spring Garden Fair Is Back!
The popular Master Gardeners Spring Garden Fair is back after a three-year hiatus! Join us on April 15 at Martial Cottle Park in San Jose from 9 am – 2 pm for our sustainable gardening showcase, premiere plant sale, and educational fair. We’ll have a variety of gardening talks on tomatoes, cut flowers, and succulents, plus information booths on tool care, troubleshooting irrigation, and more. Our huge plant sale will feature over 5,000 tomato seedlings, 2,500 pepper plants, plus a variety of herbs and flowers. And stop by our in-person Help Desk for answers to your gardening questions.
Photo credit:  Karen Schaffer
Ideas Galore for Beautiful
Waterwise Landscaping 
If you’re looking for design inspiration for adding California native plants to your garden, you’ll find a wealth of ideas on the Growing Natives Garden Tour website. Not only will this site tell you about this year’s garden tour (free, takes place April 1 and 2), but you can also find photos of all the gardens featured on previous tours going back to 2010. You can sort hundreds of photos by city, designer, or date, and even get a list of plants used in each garden and nurseries that sell them. These gardens reduce water, pesticide, and chemical use, improve habitat, and showcase the unique appeal of California native plants. Grow native!   
Photo: Salinger Garden with lupines and California poppies, Growing Natives Garden Tour
Salinger Garden with lupines and California poppies - Growing Natives Garden Tour
Should You Prep Soil for Planting?
Garden soil with young vegetables growing by Karen Schaffer
It’s tempting to grab a shovel and turn over all the soil in your garden as you prepare for summer planting. But should you? Increasingly, science is saying “no.” Every time you dig into the soil, you’re disturbing a very intricate, living web of organisms, bacteria, and fungi that your plants need to thrive. In contrast, a No-Till approach minimizes soil disturbances and keeps organic material like leaves, compost and coarsely chopped plants on the ground’s surface to slowly decompose. By keeping it moist and protected from beating sun and pounding rain, this organic material allows the soil to stay crumbly and ideal for planting.

Photo credit: Karen Schaffer
Weed Spotlight: Filaree
Filaree weed with pink flowers and storkbill like seed heads by Allen Buchinski
You may have noticed a highly prolific, rosette-shaped weed lately. Filaree (Erodium spp.) plants start out as low growing plants that can form a dense mat in open areas. They create bright pink flowers that turn into angled seed pods resembling a stork's head and beak, giving the plant one of its common names: storksbill. The spiral-shaped seeds explode out from the plant in late spring, drill into the soil with changes in humidity, and germinate with next year's rains. Recommended control methods include hoeing, hand pulling, and several inches of organic mulch.

Photo credit: Allen Buchinski
Inspect Roots When Planting
If you’re adding plants to your garden this spring, check the roots before putting them into the ground. Two things are particularly important. First, look for circling roots, which can eventually strangle the plant. Straighten them out as much as possible and consider pruning them if they’re too big to spread. Second, note where the roots start growing and plant at that depth, or slightly higher to allow for some settling. If planted too deeply, plant roots cannot get enough oxygen to grow and may suffocate and die. Planting too shallow can result in root damage from exposure and excessive drying.
Potbound oak tree showing circling roots by Jack Kelly Clark UC
Photo: Avoid purchasing plants with major roots that circle the container, Jack Kelly Clark, UC
Quiz Answer: What Is Causing These Leaves to Curl?
Help Desk submission-Jack Kelly Clark-UC ANR-Jeanette  Alosi-Butte County MG-Texas Tech University
Actually, there isn't a single answer because curling leaves are simply a symptom that can have a wide variety of causes, ranging from disease to insects to environmental factors. For instance, Photo 1 shows peach leaf curl, a disease which only affects peach and nectarine trees, while Photo 2 shows plum leaves curling due to an insect, plum leaf curl aphids. Photo 3 shows tomato leaves curling from environmental stress like heat or too much water. Finally, Photo 4 shows some leaves of a curly willow, Salix matsudana ‘Tortuosa’, and there’s nothing wrong with them because they’re supposed to be curly!

If you have questions about curling leaves or anything else odd about your plants, you can contact our Help Desk or call in to ask us about it at our monthly Plant Clinic Online.
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 Saturday of the month (April 8), from 10–noon. Priority will be given to questions that are emailed in advance; instructions are in the Zoom registration confirmation. Registration required.

Spring Tune-ups for the Food Garden, Saturday, April 1, 10–11 am, Palo Alto Demonstration Garden, 851 Center Dr, Palo Alto

Growing Natives Garden Tour, Saturday, April 1, 10 am–4 pm, Santa Clara Valley

Introducing Our New Garden! Open House!, Saturday, April 1, 10 am–1 pm, South County Teaching and Demonstration Garden, 80 Highland Ave (Corner of Montery Rd & Highland Ave), San Martin

Growing Natives Garden Tour, Sunday, April 2, 10 am–4 pm, Southern San Mateo County

Growing Summer Vegetables, Thursday, April 6, 6:30–7:30 pm, Mountain View Public Library, 585 Franklin Street, Mountain View

Best Plants for Butterflies, Bees, and Other Pollinators, Friday, April 7, 5:30–7:30 pm, Veggielution SoFA Pocket Park, 540 S. 1st Street, San Jose

Plant Clinic Online, Saturday, April 8, 10 am–noon, Online

Spring Garden Fair - Martial Cottle Park, Saturday, April 15, 9 am–2 pm, Martial Cottle Park, 5283 Snell Avenue, San Jose

Aphids, Scales, Mealybugs, Oh My!, Thursday, April 20, noon–1 pm, Online

Growing Fabulous Citrus, Thursday, April 27, 7–8 pm, Rinconada Library, 1213 Newell Rd, Palo Alto

Summer Success with the Big Three: Tomatoes, Peppers, and Eggplants, Saturday, April 29, 1–3 pm, Sunnyvale Teaching and Demonstration Garden, Charles Street Gardens, 433 Charles St., Sunnyvale
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:

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