October Tips & Events for Santa Clara County

“Autumn is a second spring when every leaf is a flower.”

~ Albert Camus

Monthly Tips

Quiz: Who Mummified These Aphids?

Ever found aphid colonies on the underside of a leaf? If so, you may have seen aphids moving between some swollen, brownish, hollow bodies. These are aphid mummies.


Who turned the aphids into mummies?

Photo: Aphid mummies and live aphids found on the underside of a leaf, Ying Chen

aphids and aphid mummies on the underside of a bean plant leaf

Join Us at Our Fall Garden Fair

Greet the cool-weather gardening season by joining us at our annual Fall Garden Fair on October 11, 9 am–2 pm, hosted in conjunction with Martial Cottle Park’s Fall Festival. Free admission, $6 parking.


Want to learn about cover crops, growing winter vegetables, starting a home orchard, and planting native plants? Attend talks on these topics and more, get one-on-one advice from Master Gardeners, and check out our many demonstrations and booths. Our plant sale offers vegetable, ornamental, and native plant seedlings, plus succulents, garlic & shallot bulbs. There will be kids activities, a seed swap, and more. See you there!

Photo credit: Derek Bryant

Fall Garden Fair signpost pointing to the many activities available at the event.

Mediterranean Fruit Fly Quarantine

A Mediterranean fruit fly perched on the surface of citrus fruit.

A large part of San Jose and surrounding areas are under a new quarantine for the Mediterranean Fruit Fly (Medfly). These destructive pests damage over 250 types of fruits, nuts and vegetables. If established, they could devastate both commercial and homegrown produce.


To prevent the spread of Medfly, people living in the quarantine zone (check your address) are urged not to move fruits, nuts or vegetables off the property where they are grown. Harvest, process or consume them at your home. Seal uneaten or unprocessed produce in plastic bags and place it in the trash. Do not compost or put it in green waste.

Many dropped apples rotting on the ground under a tree.

Photos: a Mediterranean fruit fly perched on the surface of a citrus fruit, Florida Division of Plant Industry, Florida Department of Agriculture and Consumer Services, Bugwood.org; fruit that has fallen from the tree is a potential breeding site for flies, Ying Chen

Protect & Replenish Your Soil

Taking a break from vegetable gardening this winter? Consider protecting and nourishing your soil by planting a cover crop, such as fava beans, clover, or bell beans. These plants replenish nutrients and reduce weed growth. Cut down the cover crop and work it into the soil before summer planting. Another option is sheet mulching: remove weeds, then add a layer of cardboard and cover with compost and mulch. This method blocks sunlight, smothers weeds, prevents new seeds from sprouting, and enriches soil as the cardboard decomposes. Here are some more sheet mulching do’s and don’ts.

Several types of cover crops in many shades of green planted closely together.

Photo: Fava bean plants as part of a cover crop mix including pea, hairy vetch, and oats, US Department of Agriculture

Bringing Nature into Your Home

An assortment of houseplants in pots sitting on a white counter in front of a window

Have you ever brought a beautiful houseplant home, only to have it die a few months later, leaving you to wonder what went wrong?


Come to our talk on houseplants at the McClellan Ranch Demo Garden in Cupertino and bring your questions. We’ll cover the essentials of indoor plant care. Whether you are completely new to growing houseplants or looking to grow your knowledge, you’ll leave this talk better prepared to care for your plants.


Photo credit: Canva

What Do Daffodils & Garlic Have in Common?

daffodil bulbs to plant in the fall

They are both true bulbs, which means that unlike seeds, they contain a short stem, modified leaves, and a bud. This allows them to grow more rapidly than a seed. Plant both garlic and daffodil bulbs in late October to November since they require some chill hours to break their dormancy. Make sure that the soil is well amended with organic material. Choose a sunny spot for garlic and full sun to part shade for daffodils. You can also grow either in containers. Plant garlic 1–2 inches deep and daffodils 4–6 inches deep. If our winter rains are not sufficient, be sure to keep them watered.


Photo credit: Canva

Quiz Answer: Parasitic Wasps

Some parasitic wasp species deposit their eggs inside aphids (National Geographic video). A tiny larva hatches from the egg inside the aphid body, feeding on and eventually killing the aphid. The larva pupates and continues to develop inside the papery, mummified aphid. The adult parasitic wasp chews its way out and leaves the hollow mummy through a hole. 

Parasitic wasps next to aphid mummies.

Photo: A parasitoid wasp next to aphid mummies, UC Statewide IPM Project

More October 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.

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 (October 14) 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.


The Growing Threat to Our Trees, Wednesday, October 1, 11:00 am–noon, Online


PADG Easy Seed Saving from Summer Vegetables, Saturday, October 4, 10:00 am–11:15 am, Palo Alto Demonstration Garden, 851 Center Drive, Palo Alto

 

PADG Open Garden Saturdays, Saturday, October 4, 10:00 am–noon, Palo Alto Demonstration Garden, 851 Center Drive, Palo Alto

 

Improving Your Garden Soil, Saturday, October 4, 10:30 am–11:30 am, Gilroy Library, 350 W 6th Street, Gilroy

 

Companion Planting: The Three Sisters Method, Saturday, October 4, 1:30–3:00 pm, Dr. Martin Luther King, Jr. Library, 150 E. San Fernando Street, San Jose

 

Martial Cottle Park Fall Garden Fair, Saturday, October 11, 9:00 am–2:00 pm, Martial Cottle Park, 5283 Snell Avenue, San Jose

 

PADG Open Garden Saturdays, Saturday, October 11, 10:00 am–noon, Palo Alto Demonstration Garden, 851 Center Drive, Palo Alto

 

Worms! The Fun Way to Compost, Tuesday, October 14, 6:30–7:30 pm, Mountain View Public Library, 585 Franklin Street, Mountain View

 

Growing Culinary Herbs in Santa Clara County, Tuesday, October 14, 7:00–8:30 pm, Saratoga Library, 13650 Saratoga Avenue, Saratoga

 

Plant Clinic Online, Tuesday, October 14, 7:00–8:30 pm, Online

 

Tree and Shrub Pests, Thursday, October 16, noon–1:00 pm, Online

 

MRDG Bringing Nature into Your Home with Houseplants, Saturday, October 18, 10:00 am–noon, McClellan Ranch Demo Garden, 22221 McClellan Road, Cupertino

 

PADG Open Garden Saturdays, Saturday, October 18, 10:00 am–noon, Palo Alto Demonstration Garden, 851 Center Drive, Palo Alto

 

A World of Plants without Soil, Saturday, October 18, 10:30 am–11:45 am, Willow Glen Branch Library, 1157 Minnesota Avenue, San Jose

 

Growing Blueberries in Santa Clara County, Saturday, October 18, 11:00 am–12:30 pm, Milpitas Library, 160 North Main Street, Milpitas

 

All about Seeds, Saturday, October 25, 10:00 am–11:30 am, South County Teaching and Demonstration Garden, 80 Highland Avenue, San Martin

 

PADG Open Garden Saturdays, Saturday, October 25, 10:00 am–noon, Palo Alto Demonstration Garden, 851 Center Drive, Palo Alto

 

Growing Culinary Herbs in Santa Clara County, Saturday, October 25, 10:30 am–noon, Rose Garden Branch Library, 1580 Naglee Avenue, San Jose

 

Cover Your Assets: Investing in Healthy Soil, Saturday, October 25, 1:00–2:30 pm, Sunnyvale Public Library, 665 W Olive Ave, Sunnyvale

 

Fruit Tree Basics: Three Week Course, Wednesday, October 29, 6:30–8:30 pm, Fremont Unified High School District Adult Education, 587 W. Fremont Avenue, Sunnyvale

 

PADG The Power of Compost, Saturday, November 1, 10:00 am–11:15 am, Palo Alto Demonstration Garden, 851 Center Drive, Palo Alto

 

Roses: Fall and Winter Care and Pruning, Saturday, November 1, 10:30 am–noon, Rose Garden Branch Library, 1580 Naglee 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:


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