You have to sow annual sunflowers (Helianthus annuus) every spring. The plants are not hardy and are generally only cared for in the garden for one season. How to sow sunflowers correctly and what needs to be taken into account when sowing.
When and how should you sow sunflowers?
Sunflowers should be sown directly outdoors at the end of April when the ground is no longer cold. Insert the seeds 2-3 cm deep into the soil and cover with soil. For sunflowers that bloom earlier, grow them indoors in seed trays from the beginning of March and plant them out after the Ice Saints.
When should sunflowers be sown outdoors?
You can only sow sunflowers directly outdoors when the ground is no longer too cold. If severe frosts occur after sowing, the seeds often do not germinate. If the first plants have already sprouted, they will quickly freeze again in the event of night frosts.
Therefore, wait until the end of April to sow the sunflowers.
So that the sunflowers bloom earlier, it is worth growing sunflowers indoors. The seeds can then be sown in seed trays from the beginning of March.
Sowing outdoors
- Loose the soil deeply
- Incorporate tire compost (€41.00 at Amazon) or horn shavings
- Putting seeds in the ground
- Cover with soil
- Possibly. add a layer of leaves on top
The distance between the sunflowers should be between 40 and 70 centimeters, depending on the eventual size of the sunflower variety.
Place three to five seeds two to three centimeters deep into the soil and then cover them. Keep the sowing site moderately moist.
As soon as the plants have formed the first pairs of leaves, all weaker sunflowers are cut off so that only the strongest plant remains.
Prefer sunflowers in the house
To sow sunflowers indoors, prepare a seed tray or small pots. Place three to five seeds into the soil at least five centimeters apart.
The sowing depth should be around two centimeters. Cover the sowing and keep the containers warm and bright.
After emergence, the weaker plants are cut off, as with outdoor sowing. Place the remaining sunflowers in individual pots. Keep the pots moist but not too wet.
Planting according to the Ice Saints
Since the sunflower cannot tolerate frost at all, care for the early plants indoors until mid or late May.
After the Ice Saints, you can plant the small sunflowers in the desired location in the garden or in the pot on the terrace.
If, contrary to expectations, it gets really cold again, put planting hats over the young plants.
Don’t plant too close together
Sunflowers are heavy feeders and need a lot of nutrients. Since they can also grow very large, the roots must have enough space. Sunflowers must therefore not be planted too close together.
Maintain a planting distance of at least 40 to 70 centimeters. You should never grow more than four sunflowers per square meter.
Tips & Tricks
You can also sow perennial sunflowers, but propagation works better by dividing the perennials. Since the perennials form many runners, you can also use these to propagate the sunflowers.
