Gardening in Tucson
and Southeastern Arizona

Planting Wildflower Seeds

Although native plants have evolved to survive in our demanding climate, scattering seed in your yard and expecting nature to take over does not assure success. Nature scatters thousands of seeds for each that grows. Much is eaten by animals, dries up from lack of water, or is carried by the wind to germinate elsewhere. If you want your native seeds to grow at your place, you must cover them, water, weed and help them along for a season or two. Once established, native plants require little or no effort. But do the work to get them established.

Below are suggestions. Nothing can take the place of your observations and experience. And if you simply wish to cover seeds carefully and not help them along with watering and weeding, that is a natural way. Seeds will wait until conditions are right and the plants will grow and flower in their own time.

Good soil holds water and allows young roots to grow more easily. If you do not have good soil, do not worry. Native plants can cope, they have evolved to cope, and with native plantings, your soil will improve too.

Start with a weed free area. Only double-dig if your soil is hard packed like a parking lot. Avoid rototillers if you can, because they create a hard layer of compressed dirt just below the reach of the rototiller blades. Most importantly, do not till if you live on old farmland. You have hundreds of weed seeds that will come to the surface, receive light and water and spring into competition with all that you plant.

If you must double-dig because you are starting a new garden bed, wait before sowing your seed. Water and allow the first flush of weeds to appear. Remove those weeds, water and weed again. Now you can sow your seed.

In a small area, hoe or hand weed to remove existing vegetation. Be sure to remove any and all roots of plants that come back that you do not want.

Compost gives nutrient-poor soils typical of the American southwest a boost. Shovel it into your soil or use as mulch.

In cold winter areas, sow annuals in spring after danger of frost has past, then water. You can also plant them in fall but do not water and do not expect germination until the following spring. In warm winter areas, sow annuals anytime and water whenever you wish to help germination.

Perennials, unless noted otherwise, require no special treatment for germination. Sow anytime. If you sow in fall or winter as nature does, cover carefully but do not water. Water will cause root growth that will be too shallow by the time a hard freeze comes and the young seedlings may perish. In winter, if the ground Is frozen, water cannot enter. Start watering when the soil warms.

Warm season grasses germinate when the soil is warm. That is the time to plant. If you plant when the soil is cold, cover carefully and water when the soil warms up. Cool season grasses, which need spring rain and disdain our dry soil, are not recommended for Arizona.

Nature plants seeds at all times. One of the great times, which you can take advantage of too, is the rainy season. Wait; then plant!

Do not sow too much seed in too small an area. Hand broadcast the seed over the area to be seeded. Since it is hard to distribute a small amount of seed evenly over a large area, you may wish to mix seed with sand or organic material to increase the volume you are spreading. For best coverage, go over the area twice, north to south, then east to west.

Rake to cover the seed with soil to a depth of 1/4 to 1/2 inch. Use top soil, or if your soil is low in organic matter, cover with a mixture of well-composted manure or other compost and sand. Covering the seed is critical so that it does not blow away, get eaten or dry out.

For slopes, stamp out contour lines perpendicular to the hillside to slow erosion, and then sow.

An alternative to sowing in soil, for seedlings that can be transplanted, is to sow in pea-sized gravel 4" deep. The gravel should be mixed with fine soil first. Sow the seeds into the gravel and water gently. The gravel will serve as a mulch, protecting the seeds from birds, wind and sun. Moisten the gravel daily. When the seedlings are large enough to transplant, carefully remove their roots from the gravel.

Do not sow your seed unless you are ready to mulch. Many seeds are lightweights and have built in feathers specially made to waft them into another yard.

Mulch helps keep your soil moist and can add nutrients. Soil is the best mulch, but any organic material helps.

Look around your property and neighborhood for possibilities. Do you or your neighbor have a bountiful field of native wildflowers or grasses? Native hay makes an excellent mulch. Other possibilities are leaves, weed-free straw, or aged sawdust. (Be careful of straw contaminated with deep-rooted field crops like alfalfa. They can take over your garden or fields.) Yet another possibility is old cloth (sheets or burlap bags) on top of the soil in newly-seeded areas. Cloth holds moisture on the surface, keeps birds away and provides even shade for emerging seedlings.

Whatever you use, make sure the mulch is not too deep or heavy. Compacted straw can inhibit seedling emergence. If you use an old sheet or other cloth or burlap, remove it after 2-3 weeks so the seedlings do not become spindly and white beneath it.

Binder, finely ground plant material that gets sticky when moistened, will help keep your seed, soil and mulch in place, especially on steep slopes and in windy areas. Sprinkle the binder at a rate of 1-2 pounds per 1,000 square feet over the soil and the mulch. On steep slopes, more binder may be helpful. Wet the area after putting on binder so it can do its job of holding everything to the soil. Binder is effective for about a year, by then the sun and soil creatures have decomposed it.

The watering recommendations below are for dry times, If you can sow during the summer rains or other wet periods, nature will do the work better than we know how.

Keep the seedbed damp. Water maybe 2 times a day for the first 3 weeks. This is not deep, expensive watering. It is lots of shallow waterings. If the seedlings dry out, they die. Water maybe once a day for the next 3 weeks.

When seedlings are one inch up their roots can be 3 inches down. Clearly now you can water less frequently and more deeply. After the initial 6 weeks, water deeply perhaps 2 times a week for a month, then once a week for another month, then twice monthly until frost. Make appropriate modifications for the weather and other conditions.

After plants are established, only occasional waterings are needed during dry spells.

When weeds appear, pull them out before they get too big. Otherwise a seemingly small problem will take over your native planting. With hard work, we are attempting to jump over years of successional weed growth to a more stable climax grassland or meadow in a season or two.

Once established, your lawn or meadow should require only minimal hand weeding.

Mowing stimulates tillering (vegetative growth) of grasses and helps control weeds by removing their seedheads before the seeds mature.

Short mowing can increase water needs. Do not cut newly sown grasses (especially bunch grasses) shorter than 4 inches high.

Wait to mow a wildflower meadow until after the flowers have all bloomed and set seed.