October is transition time in our gardens. The air is cooling, while the soil remains warm; together, they create the perfect planting conditions. And with any luck, we’ll soon see rain.
If the first week or two of October are still hot, put your planting on hold. But once the heat abates, get ready, get set and start planting!
1. Before you plant, be sure your garden has a solid infrastructure: Grade the property so water flows away from the house and into planting beds or bioswales, so water stays onsite rather than flowing into the gutter.
2. If your garden is heavy clay soil, layer on 3 to 4 inches of coarse, wood mulch or arborist chips (ground up trees) and let it sit at least four or five months. As beneficial microbes and tiny critters break down the mulch, they will incorporate it into the soil. You’ll be amazed at how much richer the soil will be and how much better it will drain.
3. If your garden beds are flat, bring in well-draining soil to create mounds to plant in. The mounds add texture and contour to the garden so the beds are no longer flat. Use a soil mix of 30 percent organic matter to 70 percent inorganic soil for all California natives and other water-wise, Mediterranean-climate and desert plants.
4. Be sure your irrigation system is up to date and functional before you put anything into the ground. The best irrigation for our region is in-line drip irrigation. That kind of irrigation wets the entire root zone around a plant, rather than just spots here and there. In-line drip gets plants off to the best start and s them through their lives.
5. Install an automatic irrigation controller to turn the irrigation on and off. Customize the schedule of each irrigation zone for the types of plants it waters.
6. Plant any tree, shrub, perennial, vine or succulents native to California or to our sister climates of southwestern and western South Africa, Australia, the west coast of Chile and the Mediterranean coast.
7. This is the last month to plant subtropicals like banana, citrus, avocado, cherimoya or guava. Plant now or wait until next spring.
8. Prepare to plant: Water the plant in its pot and let it drain for an hour or so. Then gently pull the plant out of its pot so you can see the rootball. 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.
9. How to plant: Once the plant is out of the container, carefully loosen the roots (except for Bougainvillea or Matilija poppy, Romneya coulteri). Set the plant into the hole, just barely higher than the plant was in the pot (it will settle). Refill the hole with the soil you dug out of the hole. Wet the soil and tamp it down as you go along to eliminate air pockets.
Once the planting hole is filled with soil, make a watering basin — basically a moat — around the stem or trunk. Set your hose to trickle water into the basin until the soil is saturated. Layer 3 or 4 inches of mulch onto to the soil surface, starting at the outer edges of the basin and covering the entire planting bed.
10. Mulch should cover nearly all the soil surfaces in your garden. It is important to leave several large bare spots for our native, ground dwelling bees. They are really important garden pollinators and they rarely sting.
11. With the sun lower in the sky, plants slow down and need less water. Adjust your irrigation clock to water less often. Make sure it always runs for the same number of minutes; all you are changing is the frequency. If you have a smart irrigation controller, check to confirm that it is making seasonal adjustments on its own.
12. Do you know how long to water? Plants take up water from their roots, so water long enough to saturate the soil around the roots. Five minutes isn’t enough and neither is 15 minutes if you are using drip irrigation. Use a soil probe and pull up a narrow core of garden soil. With a soil probe, it is easy 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 you water again.
13. Watch for the green spears of spring bulbs like Watsonia, Narcissus and species Gladiolus to pop up now. If you have bulbs that you haven’t yet planted, plant them now. They may not flower next spring, but they should flower in their second spring.
14. Looking for grasses to add to your garden? Plant these natives to make an interesting meadow: purple three awn (Aristida purpurea), nodding needle grass (Stipa cernua), deer grass (Muhlenbergia rigens) and wild oat grass (Elymus condensatus)
15. Add seeds for spring blooming native annuals to brighten up your meadow: orange California poppies (Eschscholzia californica), bright pink elegant clarkia (Clarkia unguiculata), and the diminutive yellow flowering beach suncups (Camissonia cherianthifolia).
16. Cut back spring and summer blooming sages (Salvia) so they can re-sprout afresh and flower again.
17. Harvest the last of the melons, pumpkins and winter squash when 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.
18. Divide irises. Carefully separate the rhizomes (they look like tiny, ted potatoes) at the “ts.” Use a sharp knife wiped clean with alcohol. If you divide more than one iris plant, wipe the knife with alcohol between plants so you don’t spread pests or diseases from one plant to the next.
19. Head back the branches of scented geraniums and Martha Washington geraniums early this month. Next month, you’ll cut off the long branches to force the plant to grow new shoots at the base, but for now, just shorten the branches by a couple of inches.
20. Now that days are growing shorter (and cooler), established plants like South African daisy (Arctotis) and Grevillea will go through their “second spring” bloom.
21. This is the time of year when vegetable gardeners face a dilemma. Should we pull out our tomatoes, eggplants, peppers and squashes that are still producing so we can plant greens, peas and cauliflower? Or should we leave them in the ground and wait another month to plant the cool-season crops? Hmm …
22. Always plant root vegetables from seed since they don’t transplant well: carrot, beets, radishes, turnip, rutabaga, etc.
23. Start an herb garden. Plant permanent herbs like rosemary, oregano and bay in the ground. Plant seeds for annuals like cilantro, dill and parsley into large pots or raised vegetable beds. It’s too late to plant more annual basil this year, but there are some new varieties of perennial basil whose leaves are almost as tasty as annual basils. The perennial African blue basil is great for attracting bees to the garden, and its purple leaves and flower stalks are beautiful — but it is not especially tasty.
24. Plant cover crops to add nitrogen and organic matter to your vegetable garden. Legumes add nitrogen, and grains add organic matter. Mustard helps dampen down soil pathogens like root knot nematodes, though it doesn’t entirely eradicate them. Order and plant cover crop seeds now.
25. Protect next year’s fruit and vegetable crops by cleaning up your garden now and sending the debris off in the green waste instead of composting it at home. At the greenery, they’ll be hot composted to kill off pests and diseases.
26. Feed roses with liquid fertilizer at midmonth. Inspect leaves for mold, rust or black spot. Pull or cut off infected leaves and put them into the green waste bin rather than into your compost pile.
27. Clean drains and rain gutters before the (hopefully) rainy season begins.
28. On Saturday, Oct. 12, shop for native plants at the San Diego Chapter of the California Native Plant Society fall plant sale at Casa del Prado Theater Courtyard in Balboa Park, from 9 a.m. to 3 p.m. More information is at www.cnpssd.org.
29. Thinking of redoing your garden? Sign up for a 30-minute garden design consultation with a member of the Association of Professional Landscape Designers (APLD) at the Fall Home Garden Show, Oct. 4-6 at the Del Mar Fairgrounds. Visit www.fallhomegardenshow.com and follow the link for Private Landscape Consultations to sign up.
Sterman is a garden designer and writer; www.waterwisegardener.com
