Content
- Are sunflowers hardy?
- Annual sunflowers are not hardy
- Sunflower perennials overwinter
- Do not fertilize again from September
- Sow and plant sunflowers in spring
- Tips & Tricks
Annual sunflowers are not hardy
Are sunflowers hardy?
Sunflowers come from North and Central America. There are two main types. Helianthus annuus is not hardy and is therefore considered an annual plant only. Perennial sunflowers, for the most part, are hardy and bloom in the garden for many years.
Annual sunflowers are not hardy
Annual sunflowers do not survive cold temperatures. However, it is not worth their while to hibernate them indoors as they will only thrive for one year anyway and have to be sown again next year.
When the sunflower blossoms have faded, the popular sunflower seeds ripen in it. In autumn, harvest the seeds or cut the flowers to dry.
The cores can be used in winter as birdseed. They can also be roasted as a snack or used in the kitchen for baking. It's also worth keeping a few seeds for sowing next year.
Sunflower perennials overwinter
Most perennials of the sunflower are hardy. You need, such as the Jerusalem artichoke, no winter protection at all.
More sensitive species cut off in the fall above the ground. If available, cover a layer of mature compost over it or layer some foliage. In the spring, lift off the mulch so that the sun can heat the earth better.
Some perennials are not hardy. They must be dug up in the fall and overwintered in the house. It is best if you cultivate such varieties only in the pot.
Do not fertilize again from September
Perennial sunflowers should no longer be fertilized by September at the latest. The fertilizer increases the risk that the perennials will not survive the winter.
Sow and plant sunflowers in spring
Since the annual sunflowers do not tolerate frost at all, they may only be sowed outdoors when the soil is warm enough.
You should wait until the end of May to plant sunflowers in the field. Before, the danger of night frosts is still too great.
Tips & Tricks
Annual sunflowers usually carry only one or a few flowers. When they have withered, the time of the plant is over. It can then be cut, leaving the root in the ground.