The PBS show “This Old House” recently had a little section on “fall is for planting.” The plant guy was explaining to his buddy all the great reasons for planting trees in fall (while the buddy got to do the shovel work).
It is not just in snowy climes that fall is for planting. Fall is for planting everywhere —but especially here!
Warm soils, ample sunlight, and many months until the searing heat of summer descends once more all combine to make autumn the best time to plant in southern Arizona. Fall planting gives all plants, but especially woody trees and shrubs, ample time to become well-established, with an extensive root system to anchor the plant and absorb sufficient water for a strong, healthy plant.
The soils are still warm from the summer heat, but the nights are cooler, and the days are getting shorter. This tells plants to grow. September is ideal for planting long-lived plants like trees, shrubs, perennials, bulbs, groundcovers, herbs, and vines. It is also a fine time to plant the winter vegetable garden, not to mention wildflowers and annuals. In short, autumn is awesome for planting everything.
If your yard is all planted, it is still time to get out and do a few things around the landscape. Some work now, and your yard will really reward your efforts all winter long. It is still hot enough to break a sweat as you do all this, but if you wait until October it will be too late for many garden tasks.
October planting will not give plants enough time to really get well-established before first frost.
Fertilize now. Fertilize citrus and landscape plants with a balanced fertilizer for good fall growth. Fertilize tomatoes, peppers, and pumpkins with a high phosphorous fertilizer for fall fruits. Fertilize basil, herbs and lawns with a high nitrogen fertilizer for good fall leaf growth.
Treat iron-deficient roses and citrus again if the rains leeched the treatment away. You may also need to treat magnesium deficient plants if your yard has sandy soils.
Sow now. Sow native wildflower seeds for spring display. Sow the seeds of your winter vegetables and herbs. Winter vegetables include arugula (roquette, Italian lettuce), broccoli, Brussels sprouts, cabbage, cauliflower, chard (Swiss chard), both Chinese cabbages -- bok choy and pak choy — collard greens, endive, kale, kohlrabi, lettuce (head or leaf types), mustard greens, radish, radiccio, and spinach. Peas too, yum.
Winter herbs should be planted in autumn, even thought they will die around April. Enjoy them for the cool half of the year: anise, caraway, cilantro (also called Chinese parsley or coriander), dill, fennel, and parsley.
Reap (?!) now. Keep reaping (pulling) any summer weeds. Get them before they go to seed. “One year’s seeding equals seven years weeding.” Reap too the multiple crops of the summer garden, like squash, that should be ready now if planted in July.
Water. Make sure you turn your irrigation system back on as the monsoon rains leave us. Continue regular irrigation of citrus and pecan trees for best production. Water your newly sown wildflower seeds to help get them going.
Work. No way around these chores. Deadhead or rejuvenation. prune summer-tired salvias and autumn sages for a burst of new bloom. But avoid pruning fall-flowering plants like the Mount Lemmon marigold. Divide and transplant iris. Remove any cracked or split fruits from citrus so energy is spent on good fruits. Dethatch Bermuda grass lawn for October overseeding with winter rye grass.
Here in the land of “manana,” these are some tasks that won’t wait. Winter is coming, and, mild though it may seem to us, plants still need to be prepared for it.