Lush looking perennial plants but also low water use in the desert Southwest. Sounds impossible – but it is not. All that is needed is a careful selection of plants. Plants with colorful flower because who doesn’t like some bright colorful flowers?!

Cover image above, hesperaloe, a native plant that hummingbirds adore.

Perennials to the Rescue

Perennial plants are a great way to enrich the landscape. Perennials are those that live many years, but are not woody like trees and shrubs. According to this description, saguaros and agaves qualify as perennial plants (an accurate assessment). For this article though, better to think of plants like iris or daisy when you read “perennials.”

Five Reasons to Plant Perennials

Reason 1. Most perennials bloom with colorful flowers, and often they bloom for months. Thus they add long term color to the landscape.

Reason 2. Landscape design aspect is that perennials are, in general, much shorter than trees and shrubs, thus they add an additional, layer of interest to your landscape. A layer that is down low and easily viewed.

Reason 3. Perennials save water. When placed under trees and shrubs they help shade the soil and reduce evaporation, and help trees grow better. Sounds wrong but hear me out. Perennials use water from the top foot or so of the soil. This means that the trees they are planted under will be encouraged to reach deeply for water. Thus tree and shrub roots to grow two or three feet deep for water, and incidentally anchor them better. (You are watering deeply enough, aren’t you?)

Reason 4. Less work. Flowering shrubs like bougainvillea and even brittle bush require periodic rejuvenation pruning, leading to bulky plant waste that must be dealt with. Perennials are non-woody, thus the rare rejuvenation pruning required leaves you with papery debris that can easily be composted.

Reason 5. Flowers. Outdoors yes, but indoors as well. So many perennials easily provide long-lasting cut flowers for enjoyment indoors. True, some of the these desert Southwest annuals are tiny, but a small sprig of flowers can be set in a shot glass on the windowsill by the sink, offering a bright note among the boring kitchen chores.

Low Water

Now there is a term that is a moving target. What does “low water” really mean?

The evaluation started about a hundred years ago. Folks moved to the Southwest from “Back East.” Back East, an average rainfall for most of the states is 60 to 80 inches per year. So, back in the 1930’s in the Southwest, “low water” landscape plants were considered plants that only needed 30 to 50 inches of water a year. Bougainvillea, lantana, and vinca fall into that category. So do roses for that matter.

In the 1960’s and 1970’s, wells in the Southwest started to run dry. So then the number to be considered “low water” was revised downwards. Plants from dryer areas like Texas and the Mediterranean were selected. The list now included Italian cypress, santolina, and Texas rangers (Texas rain sage), these needing only 20 to 30 inches of water a year.

The first “xeriscape” garden was touted by the Denver Botanic Gardens, in the 1990’s and was based on the shocking low of 25 inches of water a year. There are many ornamental grasses in their gallery of plants.

Sorry to say that even in 2026 and the “low water” numbers still variable. In Phoenix, where many wells are less than 100 feet deep, are very different than numbers for Tucson – where most wells are deeper than 350 feet. Thus if you turn to the AMWUA guide that I wrote for the Phoenix area, you will see plants they consider “low water” but Tucson does not. Las Vegas is still revising their guides. New Mexico has a different issue. Most of the populated regions of New Mexico are higher elevation cold desert and will have a different suite of plants.

Which Perennial Plants?

All this history is nice but perhaps you are left wondering why I bothered to mention it. Because – if we have some dry years, and water rates increase, then you might want the plants that tolerate the true low water of rainfall alone.  An actual amount, not some artificially generated number.

Which perennials should you should plant? Not any of the ones from a big box store or giant mega-nursery. You will need a local nursery for this. Perennials are supposed to live a long time so choose plants that are sourced locally and not ordered by some desk jockey in another state.

Plant for Happy

Depends on you. What colors you enjoy? What leaf shapes and colors bring you joy? Plant what makes you happy.

For lasting success, you also need the plants to be happy where you place them.

Plan Before You Shop

Plan to plant where the plants will be happy. You really need to look at total sun and heat load the plants will experience before you go shopping.  Growing in east facing areas with shade all afternoon are a very different situation than growing beside a south facing wall with big windows next to a swimming pool. In the first situation, consider it full sun. In the second case, this is considered reflected sun.

Along with the fire heat of the sun, you also need to consider winter lows (air), soil type (earth), watering regime (water), and your degree of tolerance for having to fuss with plants (ether).

And by the way, do as I say, not as I do. I try to “cheat the zone,” and then I have dead plants. My plant lists and recommendations are created based on both success and failure. 

Side Note – Plan Your Colors

Ideally you should plan a color scheme for the yard. Site your perennial plantings for sweeps of color, not little exclamation points here and there. Swaths are restful but a mess of exclamation points is chaotic. This will also make it more attractive to pollinators like butterflies and hummingbirds.

July is Not Too Late

There are a number of lush and low-water low-fuss perennials that you can plant now through July for extra interest in your landscape, some providing a long summer of color. I have listed them here with their scientific name, because the common names are very mixed up for some of these species.

You can plant them in the summer – but a bit of extra attention will be needed to help them transition from pampered nursery plants. In pots they are watered every single day, we want them to spread out their roots into the soil and survive on less water (that’s a whole ‘nother topic).

Check These Out

If you want to know more about these plants, most reference sources list them by scientific name. Ladybird Johnson Wildflower Center has a fairly nice and non-biased database of plant care.

Nurseries carry many other species not listed here. You might be tempted. Nurseries want to sell. I want you to succeed. I have not listed perennials with higher water needs and also high care needs.

Lush, low water, low care, flowering perennials
for Low and Middle Desert yards.

  angelita daisy (Hymenoxis acaulis) 
  blue curls, Arizona (Trichostema arizonica)
  blue curls, woolly (Trichostema lanatum) [more common in nurseries]
  bulbine (Bulbine fructescens) 
  candellia (Euphorbia antisyphillitica) 
  chuperosa (Justicia californica) 
  coreopsis, desert (Coreopsis biglovii)
  damianita (Chrysactinia mexicana)
  dicliptera or foldwing (Dicliptera resupinata)
  dyssodia, golden (Dyssodia pentachaeta), 
  dyssodia, threadleaf (Dyssodia tenuisecta)
  fleabane, spreading (Erigeron divergens)
  globe mallow (Sphaeralcea ambigua)
  goldeneye daisy (Viguiera deltoides)
  hesperaloe or red yucca (Hesperaloe parviflora)
  honeysuckle, desert (Anisacanthus thurberi)
  honeysuckle, Mexican (Justicia spicigera)
  honeysuckle, California (Zauschneria californica)
  marigold, desert (Bailiya multiradiata)
  milkweed, desert (Asclepias subulata)
  milkweed, pineleaf (Asclepias linaria)
  paperflower (Psilostrophe cooperi)
  paperflower, skeleton leaf (Psilostrophe tagetinae) 
  primrose, Mexican evening (Oenothera berlandieri)
  primrose, Saltillo or Baja (Oenotheria stubbei)
  primrose, white or tufted (Oenotheria caespitosa) 
  rain lily (Zephranthes species)
  ruellia (Ruellia species) 
  sundrops (Calyophus hartweggi)
  woolly blue curls (Trichostema lanatum) 
  zinnia, desert (Zinnia acerosa)
  zinnia, prairie (Zinnia grandiflora)

Closing with a Note

I shall certainly have to do more articles about each of these individually!  These (and more) are such lovely low water additions to any landscape!

More Perennial Plants and Planning and Care

The Month By Month Guide offers tips for your landscape (including perennials listed here) in every month of the year.  I have a few copies left and am offering them to you – my loyal readers. When you buy from me you get a signed copy!

From the review:

“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.”

Profits from the sale of this book go to the Horticulture Therapy non-profit Tierra del Sol Institute.  

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