September / October / November

General Tasks

Compost: Add garden waste, grass clippings, pruning material and leaves so long as they are not diseased. Turn compost and keep it as moist as a wrung-out sponge. Cover before rains start to retain moisture; cover during rainy weather to avoid the pile becoming waterlogged.

Drainage: Install downspout diverters to direct runoff to landscape trees and plants. Watch for standing water near tree trunks and the root zone of trees; divert all standing water.

Frost: Early frost is possible in Central and East County after November 15.  Protect sensitive plants from cold injury when frost is predicted.

Irrigation: Short, cool days require less water, reduce the watering time on irrigation controllers monthly by 25%. Consider turning off irrigation controllers if rain is
adequate. New plantings should be irrigated on a regular basis until they have become established.

Mulch: Refresh the spring application of mulch to bring it to 2-3”.

Soil: As the rains begin, prevent poor aeration and compaction of soil, by avoiding working wet soil or using heavy equipment on wet soil.

Tools: Clean and disinfect pruning shears that contact infected plants. Air dry and oil shears immediately after use to avoid corrosion. Organize tool shed and inventory supplies for upcoming season.

Weeds: Manage rainy season weeds before they flower, using nonchemical methods such as cultivation, hand weeding, or mowing. Use toxic chemicals only as a last resort.

Edibles

Clean-up: Control overwintering pests by removing fruit mummies and fallen leaves on the ground under fruit and nut trees, especially if codling moth is a problem. Dispose in green recycle bin; composting this material could reintroduce pests/pathogens.

Feed Plants: Stop feeding as weather cools, plants are slowing their growth or going dormant. Feed fruit trees after harvest with an appropriate fertilizer, following application rate for your product.

Harvest: Harvest mature cool season vegetables started in summer. Not sure if something is ready? This link will help: http://cagardenweb.ucanr.edu/Vegetables/.

Plan: Record information for next season, including where warm season vegetables were planted and how they fared. Begin to plan your cool season spring garden and order seeds early.

Plant: Some cool season vegetables may still be planted. Check the vegetable planting guide for your region.

• CCC Vegetable Planting Guide for Coastal Regions
• CCC Vegetable Planting Guide for Interior Regions

Protect: Watch for frost warnings (mid Nov). If a frost is predicted, protect citrus, sub-tropical and tender plants; keep the root zone moist but not soggy. After mid-November, some trees may need to be covered. If temperatures fall below 50°, cover outdoor seedlings.

Prune: Prune deciduous trees and shrubs that need pruning such as apple, pear, and stone fruits (Oct). Remove dead, diseased, broken branches. Improve tree structure by opening canopy to bring sun and air circulation to tree interior. Note: Apricot and cherry trees are the exception; prune these in Jul/Aug only.

Soil: Develop a plan to care for your soil after harvest by planting a cover crop to improve soil microbes, fertility and tilth. Find out more here: http://ucanr.edu/sites/Nutrient_Management_Solutions/stateofscience/Cover_Crops_287/.

Landscape

Clean-up: Clean up leaf debris for composting or recycle pick up. Leaf debris can be used as mulch on unprotected soil if plants are not susceptible to fungi.

Feed Plants: As plant growth slows or plants go dormant, stop adding fertilizer.

Maintenance: Clean up fallen leaves and blossoms from the area below and around your plants. Do not compost diseased material. Deep water trees adapted to summer rainfall (e.g. fruit and nut trees). Paint trunk and scaffolds with white interior latex paint diluted with an equal amount of water. Prepare for rainfall. Prevent water ponding around trunks and foundations. Improve drainage. Install downspout diverters to direct runoff into landscape soils, but avoid waterlogging of soil.

Plant: Plant California natives, bare root deciduous trees, shrubs and vines (e.g. cane berries), fruit and nuts, grapes, and roses. Select species and cultivars well-adapted to the local site. Sow native meadow flowers, spring blooming flowers and grasses. Plant spring blooming bulbs. Plant cool season annuals for color (Iceland poppy, viola, pansy, ornamental kale, etc.). Water regularly to keep root zone moist, but not soggy.

Propagate: Direct sow summer and fall annuals (cosmos, marigolds, nasturtiums, etc.) when soil temperatures are at least 70°. Divide or transplant hardy perennials (aster, chrysanthemum, hosta). Divide spring flower bulbs (daffodils, Pacific Coast iris, tulips, etc.).

Protect: If a frost is predicted, water your plants, keeping the root zone moist but not soggy. Cover frost-tender species as appropriate (bougainvillea, hibiscus and succulents).

Prune:

• Prune evergreen, summer-flowering shrubs (Sept).
• Prune deciduous trees and shrubs that need pruning such as crape myrtle, rose, and spirea (Oct).
• Make cuts properly to encourage good form and structure.
• Do not prune evergreen trees during fall, since wound closure is 20% slower.
• Remove dead, diseased, and borer-infested wood.

Integrated Pest Management for Fall

Monitor for Pests

General Pests to watch for:

• Aphids, borers and spider mites (Sept), yellowjackets (Sept-Oct), ants (Sept-Nov), carpenter bees (Oct-Nov)

Specific Pests to watch for:

• Leaffooted bug – Inspect almonds, pistachios, and pomegranates (Sept).
• Borers – Fruit and nut trees (Sept)

Specific Plants to inspect:

• Apple and pear trees – Codling moth (Sept)
• Citrus – Asian citrus psyllid (when new leaves are forming), leafminer (Sept-Nov), snails (Oct-Nov)
• Coast redwood dieback – Check for drought-stress related pests such as bark beetles and spider mites (Sept-Oct).
• Pine – Bark beetles, pitch moths, wood borers (Oct-Nov)

For further information, refer to UC IPM Pest Notes: http://www.ipm.ucanr.edu/PMG/PESTNOTES/.

Monitor for Diseases

Specific Diseases to watch for:

• Root rot (Sept-Nov)
• Cankers (Sept)

Specific Plants to inspect:

• Coast redwood dieback – Check for drought-stress related maladies such as abiotic disorders and fungal diseases (Sept-Oct).
• Citrus – Brown rot, root rots (Oct-Nov)
• Olive – Olive peacock spot or scab (Oct); olive knot (Nov)
• Pine – Western gall rust (Oct-Nov)
• Stone fruits – Monitor for leaf curl or shot hole of apricot, nectarine, peach and plum (Nov).

For further information, refer to the UC IPM Disease Menu: http://www.ipm.ucanr.edu/PMG/menu.disease.html.