May 2023 Garden Tasks

First week of May. Time to get your garden and landscape ready for the summer ahead.
Most tasks in May revolve around making sure the water system is working, and fertilizer to encourage just a little healthy growth – but not too much.

Irrigation System Tune Up Time

Irrigation systems require checking and tune-up on a regular basis. Some tasks should be done once per month, some should be done quarterly – as the seasons change.

Tune up irrigation system now with these tasks.
* clean filter – knock it out and soak it in white vinegar
* flush out debris – to take off all end caps and run the system to flush out debris.
* check timer settings - change from spring to summer program.

Walk the lines and check the system for leaks or lost emitters (a monthly chore).

This is an inefficient way to water in the desert. DRIP not spray! Roughly half of the spray will evaporate.

Fertilizer Tasks

* Fertilize established Bermuda grass lawns with a high nitrogen fertilizer.
Wait at least 2 weeks since last application.

* Fertilize roses every two weeks through bloom period.

* Fertilize deciduous fruit trees (almond, apple, fig, pomegranate, etc) with a fruiting fertilizer any time during the month. Do NOT use too much since it may cause excessive fruit drop. Read and follow label directions.

Almonds are native to desert regions and need little fertilizer.

* After mid-month, fertilize evergreen fruits (citrus, Natal plum, banana, etc.) with a fruiting fertilizer (high in phosphorous). I fertilize on Memorial Day because the next dose is on Labor Day and it’s easier to remember.

* After mid-month, fertilize established palms with a high nitrogen fertilizer. If they are date palms, and you want dates, use a fruiting (high phosphorous) fertilizer instead.deficiency-magnesium-soule

* No fertilizer for the plants in the Legume or Pea Family, this includes acacia (and it’s kin), mesquite (discussed here), Mexican bird of paradise, Texas ebony, fairy duster, and all the others that make pea-like pods. When in doubt, Wikipedia can help tell you what family a plant is in. Garden nerds like myself are constantly adding horticultural data to that site.


* About now there are lots of social media posts on how great Epsom salts are. Read my discussion about Epsom salts in our climate.

General May Tasks

* Holes in your leaves?  Not to worry !!!! It’s our pollinator friends, the leaf-cutter bees! Here’s my YouTube video about leaf-cutter bees.

* Add color with heat tolerant annuals like sunflower, celosia (cock’s comb), gallardia, and moss rose. More on warm season annual flowers – here.


* Mulch with organic mulches if you haven’t already, especially citrus and vegetables. Cedar bark mulch is wonderful for the fruit trees.

* Plant hot season vegetables and herbs, including: amaranth, muskmelon, okra, pepper, squash, tomato, basil, marjoram, oregano, and rosemary.  More at – Ten Tips for Warm Season Vegetables Success.

* Plant or transplant cacti and other succulents, such as agaves and hesperaloe. Try to do this before the 100’s hit.

* Remove spent flowers (deadhead) to prolong bloom on roses and annuals.

* Harvest any ready onions, shallots, and garlic.

Don’t forget to be careful out there! Remember the 3H’s for safety – Hat! Hydrate! Hands!   I say hands because you need to consider where your hands are going – as in this Savor the Southwest YouTube video.

Happy Gardening,


More Month by Month!

soule-books-buyWant to know more?    I wrote literally thousands of words about what to do in the garden each month in this book

“A great reference book is key to successful gardening in the region where you live. Arizona, Nevada & New Mexico Month-by-Month Gardening takes the guesswork out of gardening for anyone residing in the Southwest. With this book, you’ll know what to do each month to enjoy a thriving garden all year, from January to December. Chronologically organized, this guide is full of critical gardening when-to and how-to advice, along with illustrated step-by-step instructions.

The book’s author is Jacqueline Soule, a Tucson-based gardening expert. She knows this arid region inside and out, and she’s written several articles and books packed with her gardening advice. Arizona, Nevada & New Mexico Month-by-Month Gardening showcases Soule’s expertise in one easy-to-read guide.”

Available on my book selling site – ,and if you buy the book there the Horticulture Therapy non-profit Tierra del Sol Institute will get a few pennies – at no extra cost to you.

Note – the cover image for this post is Salvia greggii, Gregg’s salvia, AKA autumn sage, blooming now in my garden.

© Article copyright Dr. Jacqueline A. Soule. All rights reserved. You must ask permission to republish an entire blog post or article. Okay to use a short excerpt but you must give proper credit. You must include a link to the original post on our site. No stealing photos.

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