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.

1. To-do

  • 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
  • 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
  • Composting -

    Composting is a good way to repurpose yard and kitchen waste, and it provides a free method to feed plants and improve soil structure. If you are unsure about how to begin composting, take a look at this simple how-to compost page. You can also go to the UCCE Composting Education Program website to learn more about free two-hour classes offered throughout the county.

    As the weather warms up, compost piles dry out faster. Keep compost piles as damp as a wrung-out sponge to keep organisms alive and working on decomposing yard waste. Turning the pile to incorporate more oxygen also supports life in the compost pile.

    - January, February, March, April, May, June, July, August, September, October, November, December
  • 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
  • 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
  • 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
  • Garden Tools -

    When you use garden tools be sure to clean them before you put them away especially if you are cutting diseased plant materials. Cooler and wetter conditions make it even more important to wipe mud and sap off metal surfaces before storing them. Our Tool Care Tips provide more information.

    - January, April, July, October
  • 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 or using an inexpensive moisture meter. 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
  • 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
  • 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
  • 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

2. What to plant

  • "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
  • 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. They're Honey Bee Haven website has more resources, including a list of plants they grow.

    - March, April, May, June, September, October
  • Cool Season Vegetables -

    cool season leafy vegetaglesCool 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. The image displays cool season leafy vegetables such as chard, kale, lettuces, cabbage and bok choy. See our Vegetable Planting Chart for information on which vegetables to plant now.

    - 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
  • 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 help -

    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
  • Tree help -

    The city of San Jose has multiple resources for the home gardener. See their list of trees  for this area, including their water and soil requirements. 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.

    - October

3. Pests and Diseases

  • 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
  • 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
  • Codling Moth -

    "Worms" in your apples are actually the larval form of the codling moth. Codling moth larvae can cause a great deal of damage to apples, pears, plums and walnuts by penetrating the fruit and boring into the core.

    Trees should be monitored every week for signs of infestation. Infested fruit should be removed and discarded, to break the coddling moth life cycle. Sanitation is an important non-chemical step in controlling this pest. Make sure to pick up fallen fruit promptly, and pick apples with holes that are still on the tree. This will keep future populations down.

    Pheromone traps can be hung in isolated trees. But if you have just one apple tree don't bother. You will just attract codling moths to your tree.

    Fruit can be bagged for protection, but this is a very labor intensive method. Heavy infestations may require the use of pesticides on the moths, before fruit is affected. For more information, refer to the UC Pest Note on Codling Moths.

    - March, April, May, June, August, September, October, November
  • 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

    - March, April, May, June, July, August, September, 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
  • 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 tips on identifying possible Mosquito Breeding Grounds. UC has created a video titled Don't Let Mosquitoes Breed in Your Yard.

    - May, June, July, August, September, October
  • 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 sometimes other green parts. It can be found on roses, dahlias, chrysanthemums, peas and squash. Some rose varieties are so susceptible that you would be better off removing the plant.

    Powdery mildew likes warm days and cool nights. General tips: maintain good air circulation, remove summer veggies if heavily infected and clean up well, and plant resistant varieties next year.

    Powdery mildew is difficult to treat—the best method of control is prevention by planting resistant varieties—treatments are discussed in the UC Pest Note on Powdery Mildew and the UC Pest Note for Powdery Mildew on Fruits and Berries.

    - May, June, September, October
  • 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
  • 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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