One-year-old sunflowers (Helianthus annuus) are not hardy and do not tolerate minus temperatures at all. They must be sown and replanted every year. When is the best time to plant the popular summer flowers?
Sunflowers are sown first. You can sow the seeds in small pots or in a growing tray in the house. However, they can also sow the seeds directly in the open.
The disadvantage of outdoor sowing is that it is not warm enough outside before the end of April to germinate the seeds.
It is therefore advisable to prefer sunflowers indoors and plant them in the garden or in tubs on the balcony at the end of May.
Prefer sunflowers indoors
From the beginning of March sowing in the house is possible.
Prepare pots or culture dish
Plug cores into the ground
keep earth moist
Set up warm and bright
Place three to five seeds in a seed hole, as not all seeds usually grow. The seeds germinate relatively quickly. Once the plants have developed two or more leaves, remove all weak sunflowers and leave only the strongest to stand. Top the sunflowers over if necessary.
It has proved successful to plant sunflower seeds as germinated shoots. Otherwise, a larger part of the seed is stolen from birds.
Sowing outdoors from the end of April
If you want to sow the sunflowers directly outdoors, you should wait until the end of April. Prepare the ground and sow three to five grains at a time about two centimetres deep.
Preferred sunflowers to be planted at the end of May
Preferred or pregerminated sunflowers should not be planted outdoors before the end of May. Even a short frost break can cause the delicate plants to freeze to death.
Sunflowers that you would like to care for in the tub can also be planted out earlier. However, bring the vessels back into the house when the weather forecast announces night frost.
Tips & Tricks
Perennial sunflowers are, in contrast to annual varieties, largely hardy. The best time for planting perennials is August. Sunflowers planted in late summer already flower next year.