Dormant seeding in December through February works for the warm season grasses and any of the perennial or annual wildflowers. There are some advantages and disadvantages to fall seeding. Fall or "dormant" seeding imitates natural reseeding.
Salman says that gardeners who get snow by December can start sowing them and continue into February, and should have enough snow cover for their wildflower seeds to germinate.
If you live in a warm winter climate, you may choose to winter sow your wildflowers. Even though the ground doesn't freeze and harden, you can still take advantage of the dormant season by sowing seeds in January or February. You can expect your seed to germinate 2-4 weeks after planting.
In most zones, wildflower seed sowing season is in the fall, from mid-September to late November is best. This may seem counter-intuitive because after all most of us plant our potted perennials in spring to grow and flower for us in the summer.
Wildflower seeds don't need to be planted in holes; however, they should be tapped down to encourage growth. After you've scattered them over the soil, use the back of a shovel, your hand, or your foot to gently press them into the ground.
Yes, both native annual and perennial species will return year after year once they become established and are allowed to reseed. Natural reseeding of exotic garden varieties and "Domesticated" species may range from significant to minimal depending on the variety and environmental factors.
All seeds, including wildflower seeds, need ample moisture to germinate and to develop into healthy seedlings. Best results will be obtained by soaking the planted areas thoroughly and maintaining consistent moisture for 4-6 weeks. Afterwards, watering can be gradually reduced over several weeks.
Traditional planting time is October through February, but wildflowers are adaptable to many different planting regimes, and there is a broad planting window, especially on the coast. Some even swear by late summer sowings, allowing the seeds the chance to bake in the sun.
When the conditions are right, wildflower seeds will sprout within 2-3 weeks after germination. Annuals will bloom about 2-3 months after germination.
The answer is, it depends on your location or climate and the growing conditions. Spring, summer and fall are all good times to plant and grow wildflowers but the absolute best time will depend on the winter temperatures and water availability.
Planting in Climates With Cold/Freezing Winters
It they do, the wildflower shoots will die off with freezing temperatures. In cool climates, make sure ground temps are below 55 degrees. The biggest mistake people make with fall planting in cooler climates is sowing their seed too soon.
There's no question that flowers need protection from frost and freezing temperatures. Many flowering plants won't survive very long once temperatures dip below freezing and will typically die within a few hours once the mercury hits 28 degrees Fahrenheit.
The general rule of thumb is that most plants freeze when temperatures remain at 28°F for five hours. Of course, there are exceptions to this rule. Seedlings, with their tender new leaves, often give up the ghost when temperatures dip to 32-33°F. Tropical plants have differing low-temperature thresholds.
A complete listing of vegetables that can be planted in December and through the winter includes beet, broccoli, cabbage, carrot, cauliflower, celery, Chinese cabbage, collard, endive, garlic, kale, kohlrabi, leek, lettuce, mustard, onion, peas (English and snow), radish, rape, rutabaga, shallot, Swiss chard and turnip ...
If you scatter wildflower seeds at the beginning or in the middle of your rainy season, the plants can use rain to grow while they develop a very long tap root. Later, when the surface soil dries out, the long tap root gives the flower access to deep water. By definition, wildflowers do not need irrigation.
Until the wildflowers become established and start to bloom, your patch may look like a weed garden. Be patient. Once the wildflowers are established, they will choke out the weeds. Maintain your garden plants by weeding and lightly mulching with organic matter such as composted leaves during the first two years.
Annual wildflowers must be planted in the spring; or in a late fall dormant seeding. These plants need to reseed themselves to ensure flowers the following year. Planting them too late in spring or summer may not allow the plants to mature and produce viable seeds.
The correct planting depth of wildflowers is ¼ to ½ inch deep. It is not uncommon for a few seeds to remain on the soil surface. This is a good indication of proper planting depth.
It is important to avoid using more than the recommended planting rate because it can lead to poor results. Our trials have shown that heavy seeding rates can produce a thick stand of annuals with lower diversity than expected.
Sprinkle seeds over your new planting surface you have made and then water your planted area. The water will push the seeds into the soft soil just enough for them to grow. (Wildflower Seeds only want to be in the ground as deep as the seeds are long). Keep your soil evenly moist while the seeds are growing.
How long do flower seeds last? Most perennial flower seeds are good for 3 to 5 years, and most annual flower seeds should last for two to four years. Wildflower seeds, which often come as a mix of annuals and perennials, have a shelf life of 1-3 years.
To allow the seeds full sunlight, do not cover them in any way. The better seed-to-soil contact, the better chance of germination.
Seed the wildflowers directly in the compost mulch; rake lightly after seeding. Use the seeding rate recommended by the vendor, but roughly, 1 ox. of seed will cover 150 to 200 sq ft. Daily watering by rainfall or by irrigation is required for at least 3 weeks after seeding.
Full sun is a must for most wildflower varieties. Choose a sunny spot that receives 6+ hours of sun. (For areas with 4+ hours of sun, our Partial Shade Wildflower Seed Mix is a great option.) Good drainage is a requirement.