Fall is our best time to plant in the SoCal garden; here’s your October checklist

For The Union-Tribune

It’s about to happen: That one morning in the third or fourth week of October, when you wake up and the air feels different — cool, maybe a bit damp … and you know fall is here.

For us SoCal gardeners, fall’s arrival signals planting time. Are you ready?

Edible gardens

Harvest melons, pumpkins, and winter squash. Here’s how:

• Cut melons when the tendril nearest the melon turns brown.  The underside of watermelons ripen soft yellow.

• Cut pumpkins and winter squash once the stem connections are brown and dry. Rinse, dry well, and store in a cool, dry, dark location.

• Use damaged pumpkins and winter squash right away, before they start to rot (cook and freeze for winter recipes).

Sadly, tomatoes, eggplants, peppers, okra, corn, basil, summer squash and all the other beloved summer crops are starting to slow. Even if tomatoes, eggplants, or pepper plants look like they’ll keep going, they won’t grow as healthy nor be as productive next year. Pull them out by November. Replant next April or later.

Put old vegetable plants into the greenwaste. By season’s end, most are infected by pests and diseases we don’t want to overwinter in our gardens or in our compost piles.

What edibles to plant now?

• Garlic, soft or hard neck, both sold now as dormant bulbs in your local independent nursery. Garlic is a long season crop. Plant now for harvest in early summer.

– Soft neck garlic is slightly milder flavored and best suited to growing in our warm climate.

– Hard neck is more pungent, develops “scapes” (edible flower stalks), and is better suited for cold winter climates.

• Seed directly into raised beds or large containers.

– Root vegetables like beets, turnips, carrots, parsnip, rutabaga, etc.

– Beans and peas

– Parsley, dill, cilantro

• Plant seeds in containers for transplant in a month or six weeks:

– Broccoli, Brussels sprouts, cauliflower, rapini, kohlrabi, cabbage, etc.

• Plant seeds in the ground or into containers:

– Leafy greens like kale, spinach, lettuce, arugula, sorrel, etc.

How to space plants in raised beds (or in the ground if you’re a risk taker):

Crop / Inches between plants

Beets: 4 inches

Broccoli: 18 to 24 inches

Bush beans: 10 inches

Cabbage: 24 to 36 inches

Carrots: 3 inches

Cauliflower: 24 to 36 inches

Head lettuce: 12 inches

Kale: 12 inches

Kohlrabi: 6 inches

Leaf lettuce: 3 to 6 inches

Peas: 4 inches (plant in rows)

Pole bean: 6 inches

Spinach: 6 inches

If your soil seems to be worn out and in need of a boost, try planting a cover crop this winter instead of vegetables. Choose a cover crop (or mix of cover crops) to help your garden with what it most needs:

• Legumes like hairy vetch, add nitrogen.

• Grains like oats and rye, add organic matter.

• Buckwheat chokes out weeds, builds organic matter, and suppresses nematodes.

Fruit trees and shrubs

This is a great time to plant subtropical fruiting trees and shrubs like banana, citrus, avocado, cherimoya, pineapple guava and tropical guava.

My garden is “raining” delicious feijoa (aka pineapple guava aka Acca sellowiana) right now.

• The egg-shaped, sage-green fruits dot the walkway between my vegetable garden and my back door. I simply gather the fallen fruits and rinse them, quarter them, then bite into the sweet, pale white flesh.

• Pineapple guava fruits grow on tall, evergreen South American native shrubs that reach about 10 feet wide by 12 to 15 feet tall. In spring, the branches are covered in edible, bright-pink flowers.

• Grow the shrubs as a privacy screen or unpruned hedge. They are surprisingly drought tolerant, especially along the coast. Plant a pair to maximize production.

Pomegranates are ripe when the first fruits begin to split. Harvest the split ones right away, before they mold and before birds notice the bright red berries. Intact (not split) pomegranate fruits keep for months in the refrigerator. Have more than you need? Juice them to make jelly or pomegranate molasses, remove the seeds and freeze them to cook with later, and/or share fruits with friends.

If you plan to plant a pomegranate this year, taste different varieties now to find your favorite. Look for bare root pomegranate plants in the nursery in January or try your hand at rooting new ones from cuttings in December (Follow these basic directions: bit.ly/twigstofigs).

Order bare root deciduous fruit trees (peaches, pears, plums, almonds, etc.) from your local independent nursery. Most bare root fruit trees are grafted, i.e., the roots are from one tree and the stems/branches/leaves are from another, both chosen for optimal growing and fruiting in our region. So when you shop for bare root trees, pay attention to the rootstock as well as the fruiting wood.

Continue to water deciduous fruit trees (peaches, plums, apples, nectarine, pear, pluots, etc.). Water deeply once every week or two until the branches are bare.

Prune fig trees just as soon as they finish fruiting. Keep them low and wide so fruits are within easy reach. Cover the branch ends with drawstring mesh bags to keep the fig fruit fly from infecting tiny developing figs.

If your orange, lemon and other citrus trees have curled and distorted leaves, don’t panic. The culprit is citrus leaf miner — a tiny critter that burrows between the layers of leaf cells. It looks ugly but doesn’t hurt the trees nor diminish production. Don’t cut those leaves off. Cutting off infected leaves causes the tree to make new leaves, which will also get infected with leaf miner. Sprays won’t help. Just leave it alone.

Citrus greening disease is spreading, unfortunately. The quarantine has just been expanded. If you live in a quarantine zone, all citrus fruits, wood or plants have to remain on property unless bagged, sealed and put into the trash (not greenwaste). Find the quarantine map at citrusinsider.org.

Ornamental plants

Fall is our best planting time of year.  All native plants, all plants from other arid Mediterranean climate regions are best planted now through early spring. Here is a small selection to pique your interest:

• From the area around the Mediterranean sea: bay laurel (Laurus nobilis), smoke tree (Cotinus coggygria), lavenders (Spanish lavender, Lavandula stoechas, is the easiest and most reliable species here), chaste tree (Vitex agnus castus).

• From Australia: Grevillea ‘Spirit of Anzac’ and ‘Moonlight’, blue bush (Acacia covenyi  with impossibly pale blue leaves), Big Red kangaroo paw (Anigozanthos ‘Big Red’, tough as nails).

• From South Africa: Any of countless Aloe, from tree sized Aloe berbere to grasslike Aloe ‘Grassie Lassie,’ to red-bladed Aloe cameronii to red flowered Aloe ‘Eric the Red.’

• From Chile: Mayten tree (Maytenus boaria) which is a pretty good substitute for weeping willow, red flowering maple (Abutilon x ‘Nabob’ with blood-red flowers), and the succulent, brilliant pink flowering rock purslane (Calandrinia, aka Cistanthe grandiflora).

• From California: California lilac (Ceanothus species and hybrids), buckwheat (Eriogonum in myriad sizes and bloom colors), Matilija poppy (Romneya coulteri) only if you have a very large garden, bladderpod (Cleomella arborea aka Peritoma arborea is the name you are most likely to see in the nursery), or desert mallow (Sphaeralcea ambigua).

All of these plants grow beautifully in our lean soils, arid skies, limited rainfall season, and minimal precipitation. They mix well together, too!

Check your garden for emerging green spears of spring bulbs like bugle lily, baboon flower, Ranunculus and others. If you have bulbs you’ve been meaning to plant — do it now. They may not flower this spring, but they’ll bloom the following year.

Divide and plant iris, including native iris and Pacific coast hybrids. Carefully separate their underground rhizomes at the “joints.” Use a sharp knife wiped clean with alcohol. Wipe the knife with alcohol again between plants so you don’t spread pests or diseases from plant to plant.

Early in the month, shorten branches of scented geraniums and Martha Washington geraniums by a couple of inches. Next month, cut the long branches to force the plant to grow new shoots at the base.

Feed roses with liquid fertilizer at midmonth. Inspect leaves for mold, rust or black spot. Remove infected leaves and put them into the greenwaste bin rather than into your compost pile.

Garden prep and maintenance

Rake up leaves as they fall from fruit trees. Send the leaves to the greenwaste, where they’ll be composted at a high temperature to kill viruses, bacteria, molds, etc. Avocado is the only exception. Always leave avocado leaves under the plant as a “self mulch.”

Before you plant anything new, be sure your garden has a solid infrastructure:

• Efficient irrigation system using inline drip irrigation (not individual emitters).

• Plants organized into “hydrozones,” zones of plants that have the same water needs. Irrigate them accordingly.

• As climate change advances, rainstorms will become fewer but more ferocious. Keep that water onsite by directing it away into planting beds or bioswales.

• Remedy heavy clay soil, hard-packed subsoil or fast-draining sand by layering on 4 inches (or more) of coarse wood mulch or arborist chips that are 1 inch across or smaller. Do not use bark nuggets or bark chunks. Water mulch/chips, then let them sit four months or more.

• Clean drains and rain gutters before the winter storms.

• Use up remaining rain barrel water, clean out mold or algae. Make sure your rain barrel seals to keep out mosquitoes. Check the valve from your downspout as you prepare to divert (rather than collect) the first of the year’s rainfall. That first rainfall is called the “first flush.”

• Install a cistern. For every square foot of roof, an inch of rain yields 0.62 gallons of water. Capturing an inch of rainwater off 1,000 square feet of roof gets you up to 620 gallons of water! Cisterns hold hundreds to thousands of gallons, making them far more useful than rainbarrels, though more expensive to purchase and install.

DO NOT

• Do not TILL OR ROTOTILL. Tilling was the standard for generations, but research has proven that rather than “fluffing” up soil, once it settles, tilled soil compacts more than before tilling. Tilling also destroys the critical soil microflora and disrupts earthworms and other important, tiny critters that live in the soil and interact with plant roots.

• Do not WALK ON OR WORK IN WET SOIL. Wet soil may be soft and easy to dig or weed, but your weight on wet soil causes it to compact. And in the humid environment of the garden, you can unintentionally spread viruses, molds and bacteria from one plant to others.

How to plant

Perfect your planting technique:

• Water the plant in its pot and let it drain. Gently pull the plant out of its pot. Dig a hole as deep as the rootball is tall, and slightly wider. Make the hole square instead of round, and rough up the edges. Add a few handfuls of worm castings to the hole but no other amendments. Fill the hole with water and let it drain.

• Carefully loosen the plant’s roots (except for Bougainvillea or Matilija poppy, Romneya coulteri). Set the plant’s rootball into the hole, just barely higher than the plant sat in the pot.  Refill the hole with soil you dug out.  As you refill the hole, wet the soil and tamp it down to eliminate air pockets.

• When the hole is full, make a shallow moat around the stem or trunk.  Set your hose to trickle water into the moat until the soil is saturated.  Layer 3 or 4 inches of mulch onto to the soil surface, starting at the outer edge of the moat. Continue the mulch to cover the entire planting bed.

Bougainvillea and Matilija poppy can die when their roots are roughed up at planting. To plant, then, complete step No. 1 above, then turn the pot on its side and gently cut out the bottom of the pot. Use your hand to support the bottom of the plant in its pot and carefully move it into the prepared planting hole. Slice down two sides of the pot, then start to refill the hole.  After a few inches, gently pull away the remaining portions of pot. Follow step No. 3 above to finish planting.

Irrigation

With the sun lower in the sky, plants need less water, so adjust your irrigation clock to water just as long but less frequently.  If you have a smart irrigation controller, check to make sure it is making the necessary adjustments. If your controller isn’t “smart,” set the water to run less often. Don’t change the run time.

“Smart” irrigation controllers adjust your irrigation seasonally, zone by zone, depending on the type of plants each zone waters, your garden’s location, type of soil, slope, sun, shade and so on.

When you plant natives and other Mediterranean climate plants, irrigate them with in-line drip irrigation. In-line drip has emitters embedded in the lines and delivers water directly to the soil where it penetrates down to the roots. The entire root zone gets evenly wetted just as rain wets the soil evenly. Natives do great with this kind of drip irrigation.

Replace individual emitter style drip irrigation with inline drip irrigation. Individual emitter systems are neither durable nor reliable.

How long should you water? Always water long enough to saturate the plant’s deep roots. Use your fingers or a soil probe to feel how deep the water has gone. Adjust your watering schedule so water reaches the deep roots every time. For drought tolerant plants, let the soil down several inches before deep watering again.

Mulch

Wood- (not bark-) based mulches act like a sponge to hold water, keep moisture in the soil and protect soil from erosion. As the mulch breaks down, it feeds the micro flora and fauna that help build healthy soils to supports plants. Research shows that mulch can protect plants from soil pathogens, too.

Renew your garden’s mulch using organic mulch (organic = made from leaves, bark, wood, etc.) for all plants except succulents (mulch with rock or gravel) and vegetables (mulch with straw, not hay). Whichever you use, keep the mulch at 3 to 4 inches thick.

While mulch should cover the soil surfaces in your garden, leave several bare spots for native, ground-dwelling bees — these very, very important garden pollinators live singly and rarely sting.

October events

Oct. 11: San Diego Botanic Garden Fall Festival, sdbg.org/exhibitions-public-programs/2025-fall-festival.

Oct. 18: California Native Plant Society Plant Sale at the Sikes Adobe historic farmstead in Escondido, cnpssd.org/event/2025-fall-plant-sale

Want to know more?

There’s still time to sign up for “Fundamentals of Southern California Gardening,” my online course all about gardening in Southern California. Learn more at bit.ly/SoCalFundamentals.

Sterman is a garden designer, journalist and the host of “A Growing Passion” on public television. She runs Nan Sterman’s Garden School at waterwisegardener.com.