Seasonal shift calls for garden transition
Id fall surprise us by sneaking in last month? Normally, cool temperatures arrive mid-October, but it seems we are already there. And cool air combined with still-warm soil means it’s prime time to plant!
DEdible gardens
The last of your melons, pumpkins and winter squash are probably ready to harvest. Check where stem connects to the plant. If it is brown and dried, cut the stem, leaving a few inches attached to the melon/pumpkin/squash as a handle. Use damaged fruits right away, before they start to rot. For the rest, rinse, dry well and store in a cool, dry, dark location.
Tomatoes, eggplants and squashes are at the end of their productive lives. Even if they look like they’ll keep going, they won’t be as healthy nor as productive next year as they’ve been this year. Pull them out by November.
As you pull out vegetable plants, send them off in the greenwaste. By season’s end, most are infected by pests and diseases that you don’t want to overwinter in your garden.
What edibles to plant now?
• Direct seed edibles that don’t transplant well, including:
- Root vegetables like beets, turnips, carrots, parsnip, rutabaga, etc. - Beans and peas - Parsley, dill, cilantro • Direct seed or start in containers:
- Leafy greens like kale, spinach, lettuce, arugula, sorrel, etc.
• Start in containers to transplant in a month or so:
- Broccoli, cauliflower, rapini, kohlrabi, cabbage and related plants.
Plant less to get more. So many gardeners want to plant as much as they can into their garden spaces, but crowded beds translate to weak plants and poor production. Plants in raised beds can be grown far closer together than traditional row crops, but they still need plenty of room.
OR give your garden a break and plant cool-season cover crops to improve the soil for next spring. Look for:
• Legumes like hairy vetch to add nitrogen.
• Grains like oats and rye to add organic matter.
• Buckwheat to choke out weeds, build organic matter and suppress nematodes.
Fruit trees and shrubs
Pineapple guava are falling! That’s what happens when the fruits of these “self-harvesting” shrubs ripen. Collect the olivegreen fruits from the ground, rinse them and enjoy. Pineapple guava (Acca sellowiana) are South American natives that grow to 12 feet by 12 feet and make wonderful natural hedges. They are surprisingly drought tolerant, especially along the coast. Plant a pair to maximize production.
Unless you live within a few miles of the coast, plant the last of the year’s subtropical fruiting trees and shrubs like banana, citrus, avocado, cherimoya or tropical guava.
Pomegranates are ripe when you see the first fruits begin to split. Harvest the split ones right away, before they mold and before birds notice the bright red berries. Pomegranate fruits keep for a very long time as long as they are not yet split. If you are overwhelmed by fruits, 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 (nectarine, pluot, apple, etc.) from your local independent nursery. They’ll arrive in the nurseries in January.
Continue to water deciduous fruit trees (peaches, plums, apples, nectarine, pear, pluots, etc.) until their branches are bare of leaves.
Prune fig trees as soon as they finish fruiting. Keep them low and wide so fruits are within easy reach.
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.
Ornamental plants
Fall is our best planting time of year. Add color to your garden with permanent plants you can see blooming now. These are all exotic plants; native plants kick into bloom later in the year:
• Red orchid bush (Bauhinia galpinii) is a wonderful substitute for bougainvillea.This 8- to 10-foot-tall evergreen shrub has twolobed green leaves and brilliant salmon-red flowers. Drought tolerant and from South Africa.
• Arabian aloe (Aloe rubroviolacea) is a lowgrowing, rosette-forming succulent whose fleshy teal green blades are blushed red. In fall and winter, it sports candelabra of orange and red tubular flowers that hummingbirds can’t resist. Three-foot-tall by 4-footwide rosettes form pups you can leave or remove and root to replant or share. Very drought tolerant, from South Africa.
• Mexican sage (Salvia leucantha) originates from Mexico and is ubiquitous in San Diego-area gardens. Spires of deep purple flowers wave atop long, olivegreen leaves that are white and felty on the undersides. This lowgrowing perennial plant spreads by underground stems to 4 feet by 4 feet. Full sun, little to no water, cut back to the ground after the bloom is done.
• Beach sage (Salvia africana-lutea) is a tough waterwise shrub also from South Africa. It has tiny, sea-green leaves that line upright woody stems topped in peach and copper-colored flower spires. The leaves smell like the ocean when you rub them between your fingers. Plants grow 5 or 6 feet tall and up to 8 feet wide. These plants make excellent garden screens. Full sun. Little if any irrigation.
• Kalgoorlie emu bush (Eremophila glabra ‘Kalgoorlie’) comes to us from Australia. It has small, soft-green leaves that contrast beautifully with apricot and golden-yellow, tubeshaped flowers. Hummingbirds love this plant! This low-growing, evergreen shrub tops out at about 21⁄2 feet tall and 4 to 5 feet wide, making it an excellent choice for a parkway or street edging. Little if any irrigation needed. Full sun or part shade (more sun equals more flowers)
Check your garden for emerging green spears of spring bulbs like Narcissus, Watsonia, Babiana, Ferraria, Calochortus and species Gladiolus. If you have bulbs you’ve been meaning to plant — do it now. They may not flower next spring, but they’ll bloom the following year.
Divide and plant irises, 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 green waste 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 green waste, where they’ll be composted at a high temperature to kill viruses, bacteria, molds, etc.
Before you plant anything new, be sure your garden has a solid infrastructure:
• Establish an efficient irrigation system using inline drip irrigation (not individual emitters).
• Organize plants in “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 on-site 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 rain barrels, though more expensive to purchase and install.
DO NOT
• Do not TILL SOIL. Tilling was the standard for decades, but research has proved 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.
• Do not WALK ON OR WORK IN WET SOIL. Wet soil may seem soft and easy to dig or weed, but the weight of your standing 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
Polish your planting technique:
1. 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 hole but no other amendments. Fill the hole with water and let it drain.
2. 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.
3. 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 the soil surface, starting at the outer edge of the moat. Continue the mulch to cover the entire planting bed.
Bougainvillea and Matilija poppy (Romneya coulteri) 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 the 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. These kinds of 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 dry down several inches before deep watering again.
Mulch
Organic 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 support plants. Research shows that mulch can protect plants from soil pathogens, too.
Renew your garden’s mulch using organic mulch (made from leaves, bark, wood, etc.) for nonsucculent plants. Mulch succulents and cactuses with rock or decomposed granite. 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 — very important garden pollinators that rarely sting.
Learn
• Attend the 2023 Master Gardener Fall Festival on Oct. 14. Visit mastergardenersd.org.
• Oct. 12 at 7 p.m. is “Easy Garden Care: Less IS More,” my webinar on how to care for your garden. Register in advance at: bit.ly/EasyGardenCare.