Planting Wildflowers and Restoration Seed Mixes
One aspect of restoring the flora of our region is adding to the existing seed bank of the area, that is, adding native seeds to the area you live in.
So many people purchase wildflower mixes or restoration seed mixes and casually cast them in the areas of their yard they hope to populate with plants. This method of revegetation isn’t very successful in our dry climate. If your hope is to populate an area of your yard with beds of wildflowers, or revegetate parts of your property with native plants, you should know that the more work you put into the area, the more successful you will be.
First of all, you should know a key fact when it comes to plant recruitment—that is, the occurrence of seeds germinating in the wild. Even for saguaros, this doesn’t happen every year. Plants recruit on the wet years, different species depending on the timing of certain rainfall patterns (some species recruit when it is wet in the warm-season, some recruit when it is wet in the cool season).
what we call a superbloom, an unusual explosion of seasonal color produced by annual plants, happens once once or twice a decade. Otherwise annual plants come up in conditions that are extraordinary, where extra water may accumulate, and the soil is receptive in a way that encourages seed germination. Roadsides are popular sites for wildflowers because the extra water from the roads runs off to the sides, making the sides of the roads wetter. Most years, if you wander beyond the roadside, you will notice less density of wildflowers.
To get your yard producing beds of wildflowers, you will need to mimic favorable conditions for seed germination. There are a few important factors to consider.
SOIL TEXTURE
In the area you hope to populate with seedlings, it is important to make the surface of the soil receptive to moisture, and texturized. Break up the soil, at least the top few inches where it is often somewhat compacted, and if the soil texture is fine, add compost to introduce some chunkiness to the surface.
So this means dig up the area you wish to add seeds to, break up the compacted chunks, and maybe add compost to diversify the texture. Make the surface loose, and receptive to your seed, and water.
Cascade your seed over the prepared surface as evenly as you can, maybe even lightly rake the seed in. Fine seed won’t need to be raked in, but larger seed may need some help.
The chunkiness of the prepared soil surface should help the seeds find pockets of protection from the sun, from birds who can sometimes eat your seed, and where the seeds may stay a bit wetter.
MOISTURE STIMULATES GERMINATION
As we said, it is the wet years that encourages species recruitment. So keep the area you have sown with wildflower seed, or restoration seed, wet. Once you start to see some seed germination, you can back off the water a bit. But don’t be too greedy with the water—the more you put into the establishment of your bed, the more it will perform for you, and become populated with the plants you are trying to encourage.
PROPER SUN EXPOSURE
Make sure you are planting in the right sun exposure for the seeds you are planting. This will almost always mean full sun. Most wildflowers grow in full sun, though some may come up in slightly shadier locations. But sun usually produces the most flowers, and thus seeds. The more your annual plants bloom, not only will you be happier, but your yard will most likely see the return of those annuals the next season.
CORRECT SEASONALITY
While some plants use succulents or deep roots to deal with the aridity of our region, annual plants use the technique of going to seed to survive the periods of time where conditions aren’t favorable to the plant. For many of the most famous wildflowers, like poppies and lupine, this is the cool season. Cool season annual are planted in fall, as early as September or October. Most cool season annuals can be planted continually, in successions, throughout the fall, winter, and early spring. The later you plant in spring, the shorter the plants will be when they bloom. But planting in successions like this will prolong your blooming period, rather than having one, shorter, bloom period. Cool season annuals will generally bloom until it gets hot (May to June) or will give out when the soil conditions aren’t enough to support the plant (meaning the soil dries out).
Though most people are familiar with cool season wildflowers, there are also annuals that take advantage of our monsoon rains, like Arizona poppies pictured here (photo by Max Licher, SEINET). Though called a “poppy” the Arizona poppy is not related to the California or Mexican poppy at all, but to the creosote bush! It depends on warm season rains. So the time to plant these is in the summer monsoon rains, though as soon as the weather is hot, you can plant seeds of this plant and keep the ground wet to stimulate germination.
CONCERNING RESTORATION MIXES
Many restoration mixes will have a combination of both warm season annuals, cool season annuals, and perennials that may come up during either the cool or warm season. You obviously don’t need to separate out the seeds for the appropriate season. Seeds have a way of holding dormancy until all the right conditions are met. So seeds that need heat to germinate, like many legumes for instance, will lie in the ground continuing to be dormant until those natural conditions occur. So if you plant the mix in winter or spring, the cool season plants will emerge while the warm season seed will hang out, waiting for summer to come.
The same is true if you plant in summer monsoon season—the warm season plants will germinate during the monsoon, while the cool season plants will not emerge until fall when conditions they prefer inspire them to germinate.
BREAKING DORMANCY
Patience is always required when germinating desert adapted seed. Many plants have evolved to produce seed that can last a long time in harsh conditions. They may have thickened seed coats that protect the live germ and carbohydrate provisions within. So your seed may sometimes wait until a year or more later to germinate. On thicker seeds, you can use the technique of seed scarification to soften the seed coat—either by scratching the surface of the seed to allow water through, or using some sort of acid (mimicking the digestion of a seed by an animal) to soften the seed coat. For most wildflower and restoration seeds used in these mixes, this isn’t necessary.