The best time to plant seeds is after you have chosen a sunny spot and have removed the existing vegetation.
The best time of year to seed wildflowers is anytime you have a good seed bed established (we suggest weed-free compost as a perfect substrate for wildflower seeds). Seeds of wildflowers and native grasses germinate at all different temperatures and light conditions. Native grasses usually germinate in warm soils during summer months. Many wildflowers germinate in the fall and winter as the soil cools down, some in late winter as the soil warms, and others in warm summer soils. So if you are planting a mix, seeds germinate when the soil temperature and number of hours of sunlight are right.
Are you scratching your head? You’re probably used to the idea of planting lettuce on Valentine’s Day and peas on St. Patrick’s Day. It’s easy to get the impression that there’s always a single best time to plant. Certainly, if you plant vegetables too late in the season you may get fine healthy plants that get nipped by frost before they produce any vegetables for your table, but wildflowers are different.
A good mixture of wildflowers will show up at different times during the year, as they’re ready.
The exception to the rule
For water conservation and areas that lack irrigation, seed in late summer through fall, or in winter and early spring, because there is usually more reliable rainfall. If you plan to irrigate, you can sow at any time.
Putting the light layer of straw mulch over the seeds will hold moisture in so your wildflower seeds don’t dry out on the surface, and pressing them into the compost will help prevent run off if heavy rains come. Be sure mulch is thin enough so that you can still see the soil because many seeds need light to germinate.