Prepare a sunflower bed as you would for planting most vegetables. They tolerate heat and dry conditions and almost any soil type. The pH preference is 6.5 to 7.5 and the addition of composted organic matter is beneficial. Plant seeds about one-quarter inch deep directly into a prepared garden bed.
Sunflowers bloom last only till the middle of fall and it is highly unlikely to get your hands on these pretty flowers in December. If the sunflowers are late bloomers, you might still get some till October.
Once your sunflowers have died back completely and the backs of the blooms are brown, it's time to harvest. You'll also notice the seeds are plump and somewhat loose. Cut the stalk with sharp scissors or pruners, about one foot down from the flower head, and place in a container that can catch any loose seeds.
If you're looking for a rewarding and fun way to add some color and life into your garden during the cold months, then look no further. Winter sowing sunflowers is an easy yet effective method that will have you harvesting bright blooms in no time.
Many flowers carry the name “sunflower” that are, in fact, completely different species of plants. Some sunflowers are annual and survive only one season, and others are perennials that will return every year. All perennial and annual sunflowers produce brilliant flowers that are a highlight of any late-summer garden.
Annual sunflowers bloom during summer and into autumn. Sow new plants every few weeks and you'll enjoy non-stop flowers until the first frost. Perennial sunflowers bloom for a period of 8-12 weeks with some beginning as early as July and others finishing as late as October.
Sunflower seeds are easy to collect and store for planting next year. Just let the flowers go to seed, then harvest the seeds and keep them in a cool, dry place. Saving sunflower seeds is a great way to get free seeds for your garden, and it's also a fun project for kids.
Perennial sunflowers need a dormant period, so they do not make good winter houseplants. The growth dies in the fall, and the roots need time to rest and gear up for the next growing season. Leave landscape plants outdoors, move container-grown plants to a protected area, and wait until spring.
A good general rule for pruning perennial sunflowers is to cut them down to half their size in the late spring or early summer. Then, reduce their size again by a third in June or July. Keep your warm climate in mind.
Sunflowers continue to be an important oilseed crop worldwide. Many of them are used for birdseed but most are processed into vegetable oil. The green stalks are chopped like silage and used as cattle feed. The seeds and green foliage are favorite foods of many birds, mammals, insects, and butterflies.
Remove sunflower root balls from the soil.
Once dislodged, sunflower root balls should be removed from the soil as much as possible, as it will be hard to plant around the tough roots. The woody root and stalk won't compost very quickly, so consider burning them instead.
It's probably not too late to plant sunflowers
With varieties that only require a 50-60 day growing season, you should be able to plant sunflowers as late as July for fall flowers.
Sunflowers are generally planted in spring or early summer for late summer and fall blooming. However, if you live in a warmer climate, you can get a second planting in for mid and late fall flowers. Late season sunflowers may grow a little shorter or produce fewer flowers because there will be fewer daylight hours.
While not quite as large as its annual cousin, the perennial sunflower (Helianthus spp.) makes up for what it lacks in size with tons of blooms in late summer and fall.
For example, sunflowers should not be planted in the same field more than once every three to four years because of high susceptibility to sclerotinia head rot; the same applies to soybeans because of cyst nematodes. Regular crop rotation also reduces the likelihood of weeds building tolerance to herbicides.
After a sunflower has flowered its seeds can be harvested for planting again the following year. A single seed planted in the spring can produce many seeds in the autumn and these can be extracted from the seed head once a sunflower has dried out.
There are pint-sized sunflowers that grow just a foot tall and giant varieties that reach for the sky, but you don't need a big garden to grow sunflowers. These classic summer bloomers can be planted in plastic pots, fabric planters, or even buckets.
The allelopathic characteristics of sunflowers are toxic to some plants, potatoes being one of them. This process inhibits germination and can stunt the growth of potatoes. They also compete for nutrients in the soil. Potatoes should be planted well away from sunflowers to avoid them affecting one another.
annuus cultivars readily reseed in the garden if they haven't been deadheaded before self-sowing occurs. Instead, look at the flowers. Perennial varieties are native plants, and the blooms tend to be more modest, though they're still shaped like daisies, with petals that radiate from the center.
Sunflowers are fast reproducers, and one plant can create dozens of others. Plant seeds about an 1 inch below the ground. Germination occurs quickly, usually between 5 and 10 days, but spring crops produce more plants than summer crops. Spring crops are planted in April and May.