November Tips & Events for Santa Clara County
“Even if something is left undone, everyone must take time to sit still and watch the leaves turn.”
~Elizabeth Lawrence
Monthly Tips
Quiz: Mulch Depth to Prevent Weeds?
One of the biggest benefits of mulch is suppressing weeds. But how deep should mulch be to do a good job? Take a guess at the minimum depth in inches, then scroll down to see the answer.
Photo credit: Canva stock image
A large pile of wood chips which can be used as mulch
Harvest Leafy Greens Early and Often
Leafy greens
Many gardeners wonder when to harvest vegetables. One answer is to harvest when the vegetables look like the ones sold at the grocery store. But with leafy greens, home gardeners have a secret advantage: we can harvest leaves when they’re young and tender. No need to let them get big, old, and bitter. Lettuce, kale, chard, mustards, and more can be harvested leaf by leaf for months. For thickly planted patches, the cut-and-come-again method is quick and easy. Just watch for signs that plants are getting ready to bolt (send up a flower stalk). That’s the signal it’s time to harvest the entire plant.

Photo: Tender baby chard leaves for salads or cooking, Lars Beulke (Pixabay)
A Squash by Any Other Name
Did you know that pumpkin pie is made with squash? It’s true! That’s because pumpkins are just winter squash with a particular look: round, ribbed, and orange. Squash that we call pumpkins come from all three major branches of the squash family: Cucurbita pepo (Sugar Pie, Jack Be Little), C. maxima (Amish Pie, most jack-o’-lantern types, the giant ones grown for competition), and C. moschata (Dickinson, the variety commonly used for canned pumpkin, which is closely related to butternut squash). Be aware that while most winter squash are delicious, the ones bred for jack-o’-lanterns are often stringy and watery, so may not be the tastiest squash for cooking. Winter squash are grown in the summer and harvested in the fall. “Winter” refers to them being a winter food source, not when they’re grown.
Photo: Winter squash come in a wonderful array of shapes, sizes, and colors, Karen Schaffer
Varieties of winter squash
Old Container Soil, What Now?
Recycling old soil
Have you ever wondered what to do with container soil when the plants are done? Don’t throw it away! You can refresh old potting soil and use it again. Start by loosening the soil and removing all plant parts. Then mix it with fresh potting soil, and some compost if you have it. The fresh material will add nutrients and organic matter for your next round of planting. A word of caution: don’t reuse potting soil if you’ve had problems with disease, insects, or weeds. Pathogens, insect eggs, and weed seeds can remain in the soil even after a plant is removed.

Photo credit: Canva stock image
Propagate Native Plants Now
Bush anemone  - Carpenteria californica from the UC Davis Arboretum
Plant propagation is the process of creating new plants, either by planting seeds or by cutting a piece of an existing plant and encouraging it to grow into a new plant. Fall and early winter are ideal for propagating many California natives because fall rains promote healthy new growth. Propagating your own plants can be fun, especially when you share unusual cuttings or seeds with others. Another bonus – it’s a free way to expand the variety of natives in your garden without paying nursery prices. Come learn how to propagate native plants at our November 9 talk, which will also include a Seed & Cutting Exchange so you can take home new native plants for your landscape - for free!

Photo: Bush anemone (Carpenteria californica) is a deer-resistant shrub that grows in sun or shade and has fragrant flowers, UC Davis Arboretum
November To-Dos
November can be the beginning of a quiet time in the garden, but things still need to be done. Have you reduced your irrigation times? Are there flowering plants that could use cutting back? Dropped leaves to deal with? Do you have a plan for protecting sensitive plants when frost is forecast? Sometimes it’s handy to have a to-do list to help us remember what things need our attention, and the Contra Costa Master Gardeners have a great list! Take a look as you prepare for short days, cool weather, and rain.
Image credit: Canva stock image
November to-do in garden
Quiz Answer: Mulch at Least 3" Deep
A thin layer of mulch does not prevent weeds
Photo: A thin layer of mulch still allows weeds to grow, Linda Chalker-Scott,
Many gardeners err by only putting down a thin layer of mulch 1 or 2 inches deep, but that isn’t enough. The Garden Professors blog says, “A minimum of 3 inches of a coarse-textured mulch is needed to restrict sunlight from reaching the soil and prevent weed seed germination. Any less than this will enhance, not prevent, weed growth.” While some weeds may still sprout through a 3" layer, there should be fewer, and they should be easier to pull. Mulch also helps prevent weed seeds from reaching the soil, thus reducing maintenance. Plus, eliminating weeds preserves soil moisture. As an extra benefit, organic mulch feeds the soil as it breaks down.
Upcoming Events
No plant clinic November–February

Fruit Tree Basics, Wednesday, November 1, 6:30–8:30 pm, Fremont Unified High School District Adult Education, 589 W. Fremont Avenue, Sunnyvale

PADG Composting Basics Workshop, Saturday, November 4, 10 am–noon, Palo Alto Demonstration Garden, 851 Center Drive, Palo Alto

MCP Inspiration for Replacing a Thirsty Lawn!, Saturday, November 4, 10–11 am, Martial Cottle Park, 5283 Snell Avenue, San Jose

How to Grow Onions, Shallots, Leeks, and Garlic, Saturday, November 4, 10–11:30 am, South County Teaching and Demonstration Garden, 80 Highland Avenue (Corner of Monterey Road & Highland Avenue), San Martin

Tips for Growing Healthy Houseplants, Saturday, November 4, 1–2:30 pm, Sunnyvale Public Library, 665 W. Olive Avenue, Sunnyvale

Native Plant Propagation, Thursday, November 9, 7–9 pm, Cupertino Library, 10800 Torre Avenue, Cupertino

Bare Root Fruit Tree Selection and Planting, Saturday, November 11, 11 am–noon, Santa Clara City Library, 2635 Homestead Road, Santa Clara

Design Lessons from a Water Wise Garden, Tuesday, November 14, 6:30–7:30 pm, Mountain View Public Library, 585 Franklin Street, Mountain View

What's Biting Me?, Thursday, November 16, noon–1 pm, Online

Planting and Growing California Wildflowers, Saturday, November 18, 10:30–11:30 am, Gilroy Public Library, 350 W. 6th Street, Gilroy
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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