Spadefoot's Guide to Planting Wildflowers
In our region, there are a few adaptive species of plants that use an unusual way to deal with our dry seasons--they totally avoid them! That’s right, instead of developing deep roots, or succulent tissues that preserve precious moisture, some plants have adapted to our arid region by living a shorter period of time and expending the precious resources they’ve collected on producing seed. They just totally go away when it gets cruddy outside. Most of these species are annuals, but some are perennials if the soil and water is available. These plants have showy flowers to ensure pollination by insects which are often also prevalent during these seasons.
We often call these plants “wildflowers”, and we have two basic seasons that these annuals take advantage of (because we have two rainy seasons in the Sonoran Desert). The cool-season annuals take advantage of our cool-season rains, and our warm season annuals take advantage of the summer monsoons. Some species are opportunistic and may germinate whenever there is moisture and grow in the warm and cool seasons, so if you see a plant you KNOW you’ve seen in the opposite season, this is why.
This is our guide to help you get
wildflowers established in your landscape.
Know when to plant
For cool-season wildflowers (late winter into spring and early summer), start planting in September, and add successional plantings throughout the season if you want to lengthen your season.
For warm-season wildflowers (mostly summer-growing, into fall), plant in the spring after any threat of frost, and plant in succession until the end of summer.
Know what to plant
Cool season wildflowers include (but are not limited to) California and Mexican poppies (Papaver californicum and P. mexicanum), Penstemons (Penstemon spp), lupines (Lupinus spp), skyrocket (Gilia spp), indian paintbrush (Castilleja spp), toadflax (Linaria spp), beebalms (Monarda spp), chia (Salvia columbariae), bluebells (Phacelia campanularia), tidy tips (Layia spp), owl clover (Orthocarpus purpurascens), globemallow (Sphaeralcea spp), bluedicks (Dichelostemma pulchellum), flax (Linum spp), five spot (Nemophila maculata), baby blue eyes (Nemophila menziesii), ajo lily (Hesperocallis undulata), desert delphiniums (Delphinium spp), bladderpod (Lesquerella spp), primroses (Oenothera spp), tansyasters (Macheranthera spp), fleebane (Erigeron spp), monkeyflower (Mimulus spp), Texas toadflax (Nuttallanthus texanus) blazing stars (Mentzelia spp), Chinese houses (Collinsia heterophylla), and more.
Warm-season wildflowers represent more perennial species, though a few of these are annuals or will act as annuals if the cool season isn’t productive. These include Arizona poppy (Kallstroemia grandiflora), devil's claw (Proboscidea parviflora), red sage (Salvia coccinea), milkweeds (Asclepias spp), sunflowers (Helianethus spp.), beebalms (Agastache spp), chocolate flower (Berlandiera lyrata), Mexican hat (Ratibia columnifera), angel’s trumpets (Mirabilis longiflora), four o’clock (Mirabilis multiflora), desert verbena (Glandularia goodingii), tickseeds (Coreopsis and Bidens spp), parralena (Thymophylla pentachaeta), firewheel (Gaillardia spp), blackfoot daisies (Melampodium spp), sacred datura (Datura meteloides and other spp), desert senna (Senna covesii), thistles (Circium spp), eryngos (Eryngium spp), and the native zinnias (Zinnia spp).
Think outside the monocrops
Most of the time, wildflowers come up in diverse mixes, though rarely they do come up in solid monocrops of the same species. Depending on your space, consider using a diversity of species. It’s more fun to look at and attracts more diversity in wildlife as well. Also, remember that wildflowers do better planted amongst native grasses! If you haven’t planted native grasses in your landscape yet, this is a great time to start. Most of our grasses are perennial, warm-season grasses. But there are a few annual species, some often found in wildflower mixes.
Select a location
Despite the fact that we live in a hot desert, plants need sunlight, and annual plants need even more since they are very quickly converting their resources into flowers and seed. So the best spot for wildflowers is in ample sun, at least half a day. Full sun is best.
Prepare the soil and planting
The location you picked may be in amongst an established landscape, or it may be a blank slate. Either way, some preparation is suggested. If you have rock or bark mulch in the area, we suggest scraping it away first before you begin working.
Take a shovel and turn the top 4-8 inches of soil to loosen it up. Mix in some compost to improve the texture and add some organic material in the ground. Level it all out with a rake and let the top inch or so be fairly loose and airy. Sprinkle out your seed as evenly as possible. If you had mulch, carefully return the mulch over where you have planted your wildflower seed but be careful not to bury the seeds too deeply. Some light should be allowed to touch the soil. Water this in gently without washing the seeds around (keep your water wand on a low setting and take your time). You can sometimes obtain wildflowers as starts in plant nurseries, the soil preparation and watering will be the same.
Watering your wildflowers
Your wildflowers will need to be watered everyday to every other day until they germinate. After this you will slowly wean them to whatever you will need for the season (more often in the hot season, less often in the cool). The plants will tell you when they need more water by wilting. Remember that most years the wildflower season is not so spectacular. The great wildflower seasons happen on years with ample rainfall, so if you want a good showing, water plentifully. Don’t feel bad about watering plants, this is the only way we give back to wildlife--feeding plants is feeding wildlife.
Caring for your wildflower bed
As you water you may also have weeds germinating. Learn to identify them and pull them as they come up, but be careful not to pull up your wildflowers. Many wildflowers are related to weeds and can easily be mistaken.
Many people live where there are rabbits and other troublesome animals that may eat your efforts. Fence off wildflower plots to protect them from herbivory.
As wildflowers grow, you may need to thin them out. Plants growing in beds planted too thickly will not fully develop. Simply pull up the extra seedlings.
As wildflowers finish throughout the season, you can pull those plants up and either reseed what you already had going, or try something different. Most people only plant once per season and miss out on the benefits of succession planting.
You can either let the wildflowers go to seed (not pull them up until they have dried and ensured that the seed capsules have been shaken to encourage a return in the following season), or you can carefully collect and store the seeds in a paper envelope (plastic is not good for seed storage). Store seeds in a cool place. If you have room in your refrigerator, this is ideal to prevent any seed weevils from hatching and consuming your seeds.