October brings plenty of chores for home gardeners

October is the grand transition. There’s that one morning when you wake up and go outside and the air feels ... different. It’s fall. And it’s time to start planting.

Toward the end of the month, the heat typically abates (thankfully) and the soil retains its warmth, creating the perfect planting conditions for just about any ornamental plant. And soon we hope to have rain.

Edible gardens

Harvest the last melons, pumpkins and winter squash once their stems turn brown and start to pull away from the base. Leave a few inches of stem attached as a handle. Store in a cool, dry, dark location.

If tomatoes, eggplants and squashes are still producing, should you pull them out to make room for broccoli, lettuces and kale? It’s a dilemma.

As you pull out old vegetable plants, send them off in the green waste, where they’ll be hot-composted to kill off pests and diseases.

Plant root vegetables (carrots, turnips, radishes, etc.) seeds directly into garden beds. Don’t buy seedlings; they don’t transplant well.

If your vegetable beds haven’t produced as well as in the past, you might skip cool-season crops and plant cover crops to improve the soil instead. Legumes like hairy vetch add nitrogen; grains add organic matter. Buckwheat chokes out weeds, builds organic matter and suppresses nematodes. Choose the best cover crop seed for your garden. Order and plant the seeds now.

Would you like an herb garden? Plant herb shrubs and perennials such as rosemary, oregano and bay into permanent garden beds. Annuals such as parsley, cilantro and dill are best grown in very large pots or in a vegetable garden.

Fruit trees

This is the last month for planting subtropicals such as banana, citrus, avocado, cherimoya or guava. If you can’t plant now, wait till spring to plant.

Order bare root deciduous fruit trees (stone fruits, apples, etc.) from your local independent nursery. They’ll be available in January.

Are your citrus tree leaves misshapen? Does it look like some tiny insect is tunneling through the leaves? Don’t cut off those leaves. Don’t spray the plant. Your trees have leaf miner. It looks ugly but doesn’t hurt the tree or diminish production. Cutting off infected leaves causes the tree to make new leaves, which also will get infected with leaf miner.

Ornamental plants

In the shorter, cooler days of “second spring,” watch for established plants such as South African daisy (Arctotis) and Grevillea to erupt in bloom.

Once the air is cool, it’s safe to plant permanent plants in your garden — trees, shrubs, vines, perennials. Focus on vast options of “unthirsty” plants native to California, South Africa, Australia, the Mediterranean and western Chile.

Easy-to-grow California native plants include toyon, lemonade berry, California live oak, monkey flower and sages.

Choose from the ever-expanding selection of Australian Grevillea: “Peaches and Cream,” “Moonlight,” “Long John,” “Robyn Gordon” and many others. All are incredibly drought-tolerant and easy to grow. Mulch but don’t fertilize. Phosphorus containing fertilizers can kill these plants.

From South Africa, we can grow South African daisy (Arctotis), many kinds of aloe, red hot pokers (Kniphofia) and many more.

Among the Mediterranean region plants are rosemary, bay, oregano, lavenders (Spanish lavender, Lavandula stoechas, is the easiest to grow), cork oak and rockrose.

From Chile, try Calandrinia, Peruvian lily, Chilean guava, Chilean wine palm, mayten tree and Opuntia ficus-indica, aka tuna. Check your garden for young green spears of spring bulbs such as Watsonia, Narcissus and Gladiolus. If you have bulbs that haven’t yet made it into the ground, plant them now. They may not flower next spring, but they should flower the spring after that.

Plant annual spring flowers this month and next: California poppies, native farewell-to-spring (Clarkia), native tidytips (Layia platyglossa), flowering sweet peas and many more. Keep the seeds damp until they sprout. Keep young plants damp until rains begin.

Cut back spring and summer blooming sages (Salvia) so they can resprout fresh and flower again.

Divide iris. Carefully separate the rhizomes (they look like tiny, jointed potatoes) 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 one plant to the next.

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

Garden prep and maintenance

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

Grade your property so water flows away from the house and into planting beds or bioswales. Your goal is to keep water onsite and out of the gutter.

Remedy heavy clay soil, hard-packed subsoil and sand by layering on four or more inches of coarse wood mulch or arborist chips (ground-up trees) that are an inch or smaller. Water well, then let it sit at least four or five months. Beneficial microbes and tiny critters break down the mulch, incorporating it into the soil. You’ll be amazed at how much richer the soil will be and how much better it will drain.

If your garden beds are flat, create height and contour using imported soil up to 18 inches high. Use a soil mix of 30 percent organic matter to 70 percent inorganic soil for all California natives and other waterwise Mediterranean climate and desert plants. Clean drains and rain gutters before the (hopefully) rainy season begins.

How to plant

• 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 into the hole, just barely higher than the plant sat in the pot. Refill the hole with soil that came out of the hole. Wet the soil and tamp it down as you go along to eliminate air pockets.

• When the hole is full, make a moat around the stem or trunk. Set your hose to trickle water into the basin and saturate the soil. Layer three or four inches of mulch onto the soil surface, starting at the outer edges of the basin. Cover the entire planting bed.

Irrigation

Update your irrigation to inline drip irrigation. That kind of irrigation wets the entire root zone around a plant, rather than just spots here and there. Inline drip keeps water off leaves and is the most efficient irrigation. It gets plants off to the best start and supports them through their lives.

Install a “smart” irrigation controller, then set up a schedule for each irrigation zone based on the type of plant it waters, where your garden is, the type of soil in your garden, the slope, sun or shade and so on.

With the sun lower in the sky, plants need less water. If you have a smart irrigation controller, check to confirm that it is making seasonal adjustments on its own. If your controller isn’t “smart,” set it to run less often but don’t alter the run time.

Plants take up water from their roots, so however you water, do so long enough to saturate the soil down to the roots. How do you know if the water has run long enough? Use a soil probe to see how wet or dry the soil is from the surface down to a foot or more. Adjust your watering schedule so water reaches the deep roots every time, and then dries down a bit before it runs again.

Mulch

Renew your garden’s mulch using organic mulch (made from leaves, bark, wood, etc.), for non-succulent plants and rock or decomposed granite mulch for succulents and cactuses.

Organic mulches act like a sponge to hold water, keep moisture in the soil, protect soil from erosion and, as mulch breaks down, feeds the micro flora and fauna that help build healthy soils to support plants. Some research shows that mulch protects plants from soil pathogens, too.

While mulch should cover the soil surfaces in your garden, leave several bare spots for native ground dwelling bees. They are really important garden pollinators and rarely sting.

If you love to garden, join more than 11,000 of your gardening neighbors in the San Diego Gardener Facebook group, facebook.com/groups/SDGardener. It’s the place to talk local gardening 24/7.

Catch the new season of my TV show, “A Growing Passion,” on KPBS-TV at 8:30 p.m. Thursdays and 11 a.m. Sundays, and on KPBS2 at 8:30 p.m. Mondays. If you miss an episode, find it at AGrowingPassion.com. This season, we visit olive groves, meet a plant explorer, learn about dragon fruit and more.

Nan Sterman is a waterwise garden designer and writer and the host of “A Growing Passion” on KPBS television. For more information, visit waterwisegardener.com. ◆