UC Master Gardeners, Santa Clara County, CA
University of California
UC Master Gardeners, Santa Clara County, CA

October Tips

Monthly tips are categorized by To-Dos, What to Plant, or Pests and Diseases. Scroll through the list to see items in each category. Also, refer to our list of tips useful for any month.

1. To-do

  • Growing Vegetables in Containers -

    Growing Vegetables in ContainersContainer grown vegetables can be decorative as well as good to eat. Almost any vegetable can be grown in a container if given the proper care. Eggplant, peppers, tomatoes, lettuce, onions, carrots, cucumbers and herbs do well. Use our Vegetable Planting Chart to decide when to plant.

    One of the biggest problems is that containers dry out very fast and nutrients wash away. Both are solvable. Do not use clay pots, which dry out quickly. Plastic, composite or wooden half-barrels are good, but avoid dark colors that can absorb heat. Vegetables like a roomy container.

    There must be drainage holes in the bottom but it is not recommended that you put pebbles or broken crockery in the bottom. Use a good commercial potting mix, not planter or planting mix. Group the containers together so they will shade one another.

    The hot summer sun can heat the soil to unhealthy levels. Water whenever the soil is dry. You can test by digging your fingers into the dirt. You may have to water more than once a day. A simple drip system is easy to install and will make your container garden almost foolproof. Fertilize every week with a water-soluble fertilizer.

    - February, March, April, October, November
  • Winter Soil Health -
    If you are not growing anything special in your vegetable and flower beds, now is a good time to build up the soil health in anticipation of spring planting. The ground that is left bare is subject to soil erosion and you may lose organic matter that tends to be closer to the surface. Covering it with an organic mulch will soften the blows of raindrops and the mulch will slowly decompose and enrich the soil below. Fresh manure can be put on the surface and will work into the soil through rain and earthworms. Compost spread on top will also feed the soil and beneficial soil organisms. Cover crops like fava beans and vetch will protect the soil and add nitrogen, an essential nutrient for plants. And take care not to walk on wet soil so as not to compact it.
     
    More Information: Soil Health
    - October, November
  • Lawn Care -

    Be sure to water it as early in the morning as possible to avoid evaporation. This also helps reduce fungal diseases by giving the grass time to dry out during the day. Poor watering practices are the main reason for dead and dying areas in lawns and a common source of urban runoff.

    With shorter days in fall and winter, cooler temperatures, and a lower UV index, lawns will be less thirsty. Adjust the sprinklers monthly to water less as the winter rains kick in.

    When mowing, set the blade height as recommended for the type of lawn you have. Mow frequently enough so that only one-third of the leaf is removed at any one time. Dethatching the lawn with a special thatching rake is also a good idea. This removes dead material and allows water to reach the roots more easily. 

    Use the UC Guide to Healthy Lawns to learn more about mowing, irrigating, fertilizing, detaching and aerating. Better yet, take advantage of the County's Landscape Replacement Program!

    - May, June, July, August, September, October
  • Persimmon Harvesting -

    Hachiya PersimmonsHarvest persimmons. Fuyu persimmons are ready to harvest when they have their full orange color and are still slightly firm to the touch. Hachiya persimmons (with the pointy ends) must be soft and have translucent skin. If you eat an unripe Hachiya variety, you will gain a new understanding of the word “astringent”! Cut them off close to the fruit to avoid damage to the branch from yanking them off. The UC Master Gardeners of Solano County have a nice blog posting about Persimmons.

    - October, November
  • Dethatching and Aerating Lawns -

    If you still have a lawn, this is a good time to dethatch and aerate. Thatch is the layer of living and dead grass material (blades, rhizomes, stolons) that can build up on the surface of the lawn. A thin layer protects the soil surface and shallow roots from drying out from the sun, but a thick layer prevents water from getting through. A dethatching rake makes the job easier. The UC Guide to Healthy Lawns has more Information About Dethatching.

    Better yet, consider decreasing the size of your lawn, replacing it with beautiful water-wise California native plants, or a ground cover as an alternative to lawn. Choices are plentiful and include drought tolerant Lantana montevidensis, acacia, redolensis, creeping rosemary, or dymondia.

    - October
  • Don't Fertilize Now -
    Except for cool-season vegetables and lawns, most plants will be dormant or growing very slowly during this time of year. Fertilizing is most beneficial when plants are actively growing or developing fruit or flowers. Even citrus which ripens during the winter is best fertilized for the last time of the year before October 1. Some California native plants are active in the winter, but they evolved in our native soil and generally do not need supplemental fertilization. Fertilizing plants now will create tender new growth right before the risk of frost. Some nutrients cannot be taken up efficiently by plants during cold weather. The excess can leach into the groundwater or run off and reach the bay. Ultimately, using unneeded additives is a waste of resources and money.
     
    More Information: Dormant Season
     
    - October, November, December
  • Fall Cleanup -
    There are quite a few tasks to do at the end of the summer garden season, and decisions to make about what to do with the remains. Pick up any fallen or rotting fruits and vegetables so as not to attract critters. It’s particularly important to remove dried-up fruit “mummies” so that the fungal spores don’t spread. Also, remove dead or dying plants so as not to harbor pests and diseases. You can leave healthy fallen leaves in place to form a mulch and decompose naturally, or you can rake them up and add them to the compost pile with other disease-free plant material. Do not compost diseased material. You may want to take notes on what did and did not do well in this season’s garden, for future reference.
     
    - October
  • Garden Maintenance Items in the Fall -

    Remove or replace spent annuals. Trim woody or overgrown perennials. Trim diseased leaves from roses, camellias, rhododendrons, and azaleas. Discard in trash. Many insects and diseases over winter in plant debris so remove the yard waste from under plants. If you have oak trees, pines or junipers leave the fallen litter under these trees because it protects the roots.

    - October, November
  • Organic Soil Amendments -

    After harvesting remaining summer crops, add amendments such as blood meal, alfalfa pellets or fish emulsion to replenish nitrogen in the soil. Add a layer of compost to all existing garden beds to provide needed nutrients for winter crops. Be sure to leave some areas of native soil for ground-nesting bees.

    - October
  • Apple and Pear Harvest -

    The harvest for apples, and some varieties of pears (Bosc, Comice, Winter Nellis, and some Asian Pears), is likely coming to a close. When harvest is finished, irrigate and fertilize the trees as you have been. Clean up fallen leaves and fruit and discard to prevent apple scab and coddling moth.

    - October
  • Almond and Walnut Harvest -

    Almonds are harvested when the shell is cracked and brown. Freeze nuts for 1-2 weeks to kill resident worms, store nuts in plastic bags to prevent re-infestation, and spray the tree with fixed copper during or after leaf fall but before rains start to reduce damage from shot hole fungus.

    Walnuts are fully mature when green hull begins to break away from the shell. Harvest by poling or shaking the tree. Remove the green hulls, then freeze nuts in the shell to kill any resident worms. Store in plastic.

    - October
  • Fall Irrigation -

    You can still expect some warm weather during October, so keep watering the garden until the fall and winter rains begin. As temperatures drop, less water is needed for plants.

    Check your soil periodically by digging gently into the soil next to the root, about 6 inches down (deeper for bigger plants). If the soil does not hold a shape when squeezed it is too dry; if it continues to hold shape after the pressure is released it is too wet; if the soil has a shape then crumbles quickly, it has the right amount of water.

    Hydrozone any new plantings by putting plants with similar water needs together. This helps ensure that less water is wasted and that all plants get the right amount of water.

    If you have an automatic watering system, this is a good time to inspect the system for leaks and blockages, check the timer for batteries, and reprogram the system as necessary for cooler weather and rain.

    If you don't have an automatic watering system, think about installing one. Many systems are very affordable and easy to install by the home gardener. Take a look at some "smart meters". They are more expensive, but incorporate weather conditions, your location, and your soil into the programming, making them very efficient.

    - October
  • Olive Harvest -

    Harvest olives grown for the table when fruit is still green. Olives grown for oil can be harvested when the fruit is yellow to reddish-purple and the flesh is still green-yellow. Continue irrigating until first rains. Apply fixed copper to prevent peacock spot before the first major rain, and be sure to wash the fruit before use or wait until after harvest to spray.

    - October

2. What to plant

  • Planting Berries -

    Berries including blackberries, raspberries, blueberries, and some strawberries can be planted in the fall through early spring. When purchasing blackberries and raspberries, it is best to get plants that are certified disease-free from a nursery. Most berries prefer deep, well-drained, loamy soil with a slightly acidic pH (5.5-6.5). Bare-root plants can be planted in the fall, winter and early spring. Potted green plants can be planted any time they are available in the nursery. A northern sun exposure is best.

    - October
  • Shrubs -

    Looking for shrubs to fill out your landscape? Ceanothus, manzanita, Monardella villosa (coyote mint), ribes (currant), toyon, buckwheat are all good choices. For a more complete list, consult trees, shrubs, & woody ornamentals and learn how to plant and care for them with cultural tips for trees, shrubs and woody plants

    - October
  • Cover Crop -

    After feeding your family all summer long, perhaps you feel it's time to feed your soil. Cover crops are ideal for putting nutrients back into your soil and keeping weed growth to a minimum. Some favorite cover crops include fava beans and clover. Here is a short video on planting a cover crop.

    - October
  • Going Native -

    Native shrubs, trees, and flowers are well-adapted to our climate and soil, and support native butterflies and bees and other wildlife. They are drought-tolerant once they are established, but need adequate water for the first year or two to establish a strong root system that will help nourish the plant for years to come. Planting them in the fall gives them time to settle in before being hit by the heat of the summer sun. Consult Water Wise Plants and the California Native Plant Society for more information.

    - October, November
  • Attracting Bees -

    Bees are pollination workhorses, increasing garden production. Many plants will not produce fruit unless flowers are pollinated. Colorful annuals, such as Cosmos, edible African Blue Basil, and Salvias attract bees. You can also allow herbs and other plants to flower to create bee-friendly landscapes.

    The University of California at Davis has a garden dedicated to bees. The Honey Bee Haven website has more resources, including a list of plants they grow.

    - March, April, May, June, September, October
  • When to Plant Cool-season Vegetables -

    In Santa Clara County, cool-season vegetables such as beets, Cool season leafy vegetablesradishes, peas, arugula, bok choy, chard, collard, lettuce, mustard greens, broccoli, cabbage, and spinach, can be planted in very early spring for early summer and harvested before they bolt (go to seed), or in late summer for harvest in winter. Use our Vegetable Planting Chart as a planting guideline.

    Cool-season vegetables grow well in temperatures ranging from 55°F to 75°F. Take a good look at your garden to determine the best areas for planting, remembering that cool-season vegetables need 6-8 hours daily of sun. 

     

    - February, March, April, September, October
  • Asian Vegetables -
    You can easily grow some vegetables used in different types of Asian cuisine and found in Asian markets. They are not necessarily native to Asia but have found their way into various cuisines. One way to decide which food to grow yourself is to choose varieties that aren't readily available or are more expensive in your local markets. It’s also fun to impress your family, friends, and neighbors with something they may not have seen growing before. Possibilities include sesame seeds, bitter melon, daikon radishes, gai choy, and opo. You can start cruciferous vegetables such as bok choy and Napa cabbage from seed now.
     
    More Information: Asian Vegetable Varieties
    - February, March, April, May, June, September, October
  • Tree help -

    The city of San Jose has multiple resources for the home gardener. See their webpage on tree care. Oak trees (valley, live, blue), big leaf maples, and buckeyes are great choices for our region.
    SelecTree: A Tree Selection Guide from CalPoly can help with selecting the right tree for the right place in your landscape.     
    Apply for stewardship of one or more trees for 3-5 years at Our City Forest.

    - September, October, Any month
  • "Arboretum All-Stars" -

    Arboretum All Stars logoThis is the best tool for landscape planning available to Northern California gardeners! The UC Davis Arboretum All-Stars are plants found to be especially successful in California. The website covers essential planting basics for landscape planning, including easy-to-grow plants with low-water needs, fewer pest problems, and other outstanding qualities. As an added bonus, most are California natives that attract beneficial wildlife.

    - April, October, Any month
  • Vegetable Planting Chart -
    Wondering what vegetables can be planted now? To get the best success—whether planting from seed or transplants—refer to our Santa Clara County Vegetable Planting Chart. It's based on our own garden experiences.
     
     
     
    - February, March, May, June, July, August, October, Any month
  • Ornamental Shrubs and Trees -
    Spring is when thoughts turn to planting, yet fall is an excellent time to plant perennials. You can plant many trees, shrubs, and other long-lasting plants in fall. This applies particularly well to California native plants. Putting them in now will give them a chance to start developing strong root systems with the winter rains before they are stressed by summer heat. Developing a healthy root system early in the life of a plant is important for long-term success.
     
    When choosing plants, consider our general Mediterranean climate as well as the microclimate of your yard. Sun times, water needs, wind exposure, and soil type can all impact the success of a plant. Make sure you know how large the plant will become, even if it looks fine now in a one-gallon or five-gallon container.
     
    More Information: Tree Selection Guide
    - September, October, November

3. Pests and Diseases

  • Snails and Slugs -

    Snails and slugs are patrolling your garden right now looking for new growth. Our preferred non-toxic method for dealing with them is to handpick early in the morning, or at night by flashlight. They can be saved for your friends with chickens, or crushed in place. If you do use snail bait, those made with iron phosphate are not toxic to pets and wildlife and they work well enough. For a full run-down of which management methods work, see the UC Pest Note on Snails and Slugs.

    - February, March, April, June, October
  • Integrated Pest Management and Beneficial Insects -

    UC IPM LogoOur gardens contain far more beneficial insects than pests. Any time pesticides are used, both good and bad insects die. This upsets garden ecosystems. Use of pesticides can also pollute waterways and may put our children and pets at risk, along with other environmental consequences. We can dramatically reduce pest problems by practicing  Integrated Pest Management, which includes planting native species, following good cultural practices, and encouraging beneficial insects, such as lady beetles, lacewings and soldier beetles

    - April, May, June, July, August, September, October, Any month
  • Bagrada Bug -

    Bagrada BugThe Bagrada bug is a small (1/4”) stink bug that is most commonly found on vegetables in the Brassica family including cabbage, cauliflower, broccoli, kale, turnip, and mustard greens. Home gardeners should carefully inspect their plants and shipping containers prior to planting. A good time to inspect is right after watering when pests hiding in the space between the potting mix and the sides of the container may be flushed out and more easily detected. Plant seedlings late this month when they are big and robust. If you find nymphs on the plants, use insecticidal soap. See UC Pest Note on Bagrada Bug for further information.

    - October
  • Cabbage Aphids -

    The grey-green cabbage aphid is often found on cool season vegetables. They prefer to feed on the youngest leaves and flowering parts and are often seen on cabbages, broccoli, and Brussels sprouts.

    Hose them off plants or prune out infestations. Grow flowers in your vegetable garden to attract beneficial insects, which are their natural enemies.

    See UC Pest Note on Cabbage Aphid to identify and manage this insect.

    - October
  • Leafminers -

    Watch for damage from leafminers on leaves of beets, chard, and spinach. Eggs are inserted into leaves and larvae feed between leaf surfaces, creating a "mine." Plant resistant species or varieties. Small seedlings can be protected by protective cloth. On plants such as cole crops, lettuce, and spinach, clip off and remove older infested leaves. Place leaves in plastic bag, and put bag in trash. Leafminers are often kept under good control by natural parasites. Insecticides are not very effective for leafminer control. See UC Pest Note on Leafminers for additional information.

    - October
  • Cabbageworms -

    Examine your cabbage and broccoli plants for imported cabbageworms. Larvae are green and very hairy, with an almost velvet-like appearance. Handpick the worms. The adult cabbage butterfly is white with one to four black spots on the wings; they are often seen fluttering around the fields. Whitish, rocket-shaped eggs are laid singly on the undersides of leaves. The cabbageworm is active throughout the year in California. Use row covers or screening to keep the adults out of your vegetables. For more information see UC Pest Note on Imported Cabbageworm.

    - October, November, December
  • Powdery Mildew -

    Powdery mildew on squash leaves

    Powdery mildew fungus is a common disease on many plants and produces a white powdery appearance on leaves and other plant parts. It can be found on roses, dahlias, chrysanthemums, peas, squash, and more. Some plants are so susceptible that you would be better off removing the plant.

    Powdery mildew likes warm days and cool nights. Unlike most other fungi, it does not need moisture to thrive. Early symptoms include yellow chlorotic spots on the leaves. The presence of the fungus becomes obvious as it starts to produce spores that look like white powder on leaves and sometimes on fruit. Eventually, the leaves will turn brown and dry.

    Some strategies for dealing with powdery mildew are planting resistant varieties, maintaining good air circulation, washing off the powder in the mornings, using sulfur sprays (careful with edibles), and removing affected parts.

    More Information about powdery mildew on: Fruits and Berries, Ornamentals, Vegetables
    - May, June, September, October
  • Mosquitoes May Be Breeding In Your Yard -

    According to Santa Clara County Vector Control, many people are unaware they may be raising mosquitoes in their backyard, they offer mosquito tips including identifying possible breeding grounds. UC has created a Youtube video titled Don't Let Mosquitoes Breed in Your Yard.

    - May, June, July, August, September, October
  • Sooty Mold -

    Aphids, scale, mealybug and whitefly all excrete sticky honeydew that is colonized by sooty mold fungi. By itself, the fungi cannot kill the plant but it can coat the leaves to the extent that sunlight is prevented from reaching the leaf surface. A strong stream of water will wash the mold off leaves. The mold can be washed off fruit with mild soap and water. See UC Pest Note on Sooty Mold for more information.

    Ants protect the sucking insects from their predators in order to eat the honeydew. Keep ants out of trees and away from honeydew-producing insects by applying a sticky compound such as Tanglefoot on a tape wrapped around the trunk.

    Trim tree limbs touching buildings, fences or other access points as well. Baits such as ant stakes placed under trees and shrubs may help reduce ant foraging in some cases.

    For ant information, see the UC IPM Pest Note on Ants.

    - August, September, October, November

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