Garden Calendar for September 2018

In Southern Arizona, 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 trees, shrubs, perennials, annuals, bulbs, groundcovers, wildflowers, herbs, vegetables,,,, in short, everything!

Plan on getting out and doing some planting this fall. Some work now, and your yard will bloom all winter long. It is still hot enough to break a sweat as you do all this, but waiting until October will not really give plants enough time to grow and become well enough established before first frost.

Before Mid-September
* Fertilize citrus and landscape plants with a balanced fertilizer for good fall growth.
* Fertilize tomatoes, peppers, gourds, squash, 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.
* Order spring flowering bulbs for planting in October.

Any time in September
* Divide and transplant iris.
* Sow native wildflower seeds now for spring display.
* Deadhead summer-tired salvias and autumn sages for a burst of new bloom.
* Avoid pruning fall-flowering plants like the Mt. Lemmon marigold.
* Keep pulling the weeds.
* Continue regular irrigation of citrus and pecan trees for best fruit production.
* Remove any cracked or split fruits from citrus so energy is spent on good fruits.
* Dethatch your Bermudagrass lawn now for October overseeding with winter rye grass.
* Watch for alkaline-induced-iron-chlorosis, especially in citrus and roses. Treat with mild acid such as used coffee grounds, or 1/2 cup vinegar in 4 gallons of water. I will write more on this topic in a future post, or see my book Month by Month Guide to Gardening in Arizona, Nevada, and New Mexico.

Some plants can’t get the iron they need from alkaline soils. Increase soil acidity and the plant quickly recovers.

After Mid-September
* Plant the fall/winter vegetable garden, or at least get the area prepared. You will be planting all the “cool season” vegetables – leafy greens, root crops, and peas.

A smaller size carrot will grow better in most Southwestern gardens. Photo courtesy of All American Selections.

Want to learn more? Look for my free lectures at your local Pima County Library branch, Tubac Presidio, Tucson Festival of Books and other venues. After each event I will sell and sign copies of my books, including Southwest Fruit and Vegetable Gardening (Cool Springs Press, $23).
© Article copyright by Jacqueline A. Soule. All rights reserved. Republishing an entire blog post or article is prohibited without permission. I receive many requests to reprint my work. My policy is that you may use a short excerpt but you must give proper credit to the author, and must include a link back to the original post on our site. Photos may not be used.

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1 thought on “Garden Calendar for September 2018”

  1. Thank you so much for all information you shared. It’s very useful. I am not a green thumb at all and following your advices hoping to make my desert more attractive

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