Growing Wildflowers in the Sonoran Desert
                                                              by Lynn Walsh
 

Nature evolved desert plants with unique characteristics to survive and thrive in our desert. El Nino's wet winter last year resulted in a spectacular natural Wildflower display that was the best in 30 years. The right mix of temperatures and regular watering magically awakened and nurtured long dormant Wildflower seeds. Michelle Rauscher, the horticulturist in charge of the Desert Wildflowers Beds at the Phoenix Botanical Garden, generously shared her expertise with me about her nursery industry experience with fertilizers, chemicals, and traditional gardening techniques. These practices worked against her goal of Wildflower propagation. Like many new desert gardeners, she learned the hard way that disturbing the desert's fragile crust by tilling the soil before sowing seeds stimulated dormant seeds of weeds (any plants that grow where you do not want them) to burst forth and out compete her Wildflowers. Instead of delightful Wildflower beds, she had fields of the most invasive and aggressive weeds. It took her about five years to finally eradicate (weeding by hand) those prolific weeds. 

Another miscalculation involved using fertilizers that resulted in very large, very green plants that produced very few blooms. Many common nursery practices were developed to grow exotic plants not native to our desert soil. 

Mid-October through early December is the best time to seed for our spring desert flowers. Tilling the soil is necessary only if the ground has been compacted such as when construction vehicles drive over it. Michelle lightly rakes or crumbles about "one inch" of the ground so that the seeds can get into the soil. She does recommend leveling the bed so that seeds grow evenly and don't puddle with watering. She just presses the seeds in. She does not dig or bury the seeds. She tries to imitate nature.

Fairy Duster	Desert Marigold	Desert Lupine

Most desert Wildflower seeds are very small so she mixes them with sand (or soil) in a container that she marks with a halfway indicator so that all the seeds don't end up in one area. She suggests sowing the seeds in your already irrigated areas. It's less expensive and less work. Look for the wet areas in your drip irrigation and sow the seeds there.

The key to successful germination is to keep the soil moist until the seedlings emerge. How often to water depends on many factors including soil content, sun exposure, temperature, rainfall, etc. She recommends monitoring each location. Some may need sprinkling twice a day, others once every two days. 

Another key factor is to protect seeds and seedlings from being the local wildlife grocery store. Chicken wire enclosures with bird netting on top need to be secured tightly so that our curious Cactus Wrens, etc., can't be caught inside the enclosed area. Don't bunch the netting on the ground because it's like a magnet for lizards and snakes. The white frost cloth that lets the sunshine in also is a good alternative. One of our Desert Awareness Committee members grows great Wildflowers by dropping selected seeds in her clumps of bursage. These wonderful plants that act as key nurse plants to the saguaro also protect penstemon and other flowers while providing a bit more organic matter at its base.

A beautiful Wildflower bed is a joy to experience but does require a lot of work until established. Michelle cautions that it takes 3 to 5 years to establish a field of Wildflowers and it takes a lot of hand thinning and weeding. She recommends starting a small area close to where you relax in your garden. Pick out some good perennials (plants that grow and bloom for more than one year) and make them your mainstay so that every year you'll have brilliant blooms. Pick some with foliage that remains attractive all year.

Look to nature and your own neighborhood to see what grows where. The Desert Botanical Gardens have many great demonstration beds. Copy nature: ask neighbors for seeds from plants you like. Join us for our annual spring Wildflower walk. Research and understand what you are bringing into the ecosystem. Select seed packets of Sonoran Wildflowers native to our area. Michelle prefers to mix her seed selections herself instead of using readymade mixes. She urges home gardeners to collect and save seeds for next year. Cutting off dead plants at their base instead of pulling them up is another tip. And please don't use a hoe or next year you'll have twice as many weeds.

Blue Dick	Penstemon	Globe Mallow

Remember mid-October is the time to spray with a pre-emergent weed stopper any area that you have problems with weeds and are not going to sow seeds. It's good fire insurance for next summer. Our Sonoran desert is wonderful. Do your part to preserve and enhance our fragile beauty. And may our springtime be filled with beautiful native wildflowers.

Michelle is one of the featured speakers at our fall series of Desert Awareness Classes of the Desert Foothills Land Trust. Learn all about wildflowers - what to plant, where to get the seeds, what works and doesn't work. Call 480-488-3849 for information or check out our Fall Classes.