It takes a long time for the sunflower blossoms to shine in their full splendour. Unfortunately, annual sunflowers are not hardy and may only be sown outdoors from the end of April. You can shorten the waiting time by coming in early.
How to grow sunflowers indoors?
To prefer sunflowers, sow in seed trays, small pots or on the windowsill from the beginning of March. Keep the soil moist but avoid water stagnation. After germination and development of at least two leaves, prick out or transplant the plants.
Sowing sunflowers indoors
- Prepare the seed tray
- Sowing sunflower seeds
- Cover with soil
- Set up warm and bright
From the beginning of March, fill a seed tray with normal garden soil. If you have enough space on the windowsill, you can also sow the sunflowers in small pots. Then you don't need to prick out the plants later.
Always sow three to five seeds in a planting hole. Sunflowers germinate very irregularly and not every seed grows into a plant.
The cores should be inserted approximately two centimeters deep into the substrate and covered with soil.
Care for sunflowers in the house
Place the seed tray or small pots in a location where it is nice and warm and bright.
Keep the soil well moist, but make sure that the water does not pool. This would cause the kernels to rot.
It only takes a few days until the first seeds have germinated and the little plants start to grow.
Pricking out sunflowers
As soon as the plants have developed at least two leaves, pinch off all but one of the plants per seed hole. Only the strongest remains standing.
When growing in the seed tray, you have to prick out the sunflowers and transplant them into small pots.
Sunflowers that have been grown in pots should only be repotted if the pot is too small and the roots are sticking out at the bottom.
The sunflowers can move from the end of May
You may only plant early sunflowers outdoors when it is warm enough outside and, in all likelihood, there will be no more night frosts. This usually happens at the end of May after the Ice Saints.
If it is already very warm outside and you don't want to wait any longer before planting, be sure to monitor the weather.
If night frosts are forecast, protect the small sunflowers at night with a protective cover. You can get protective covers from gardening stores. You can also easily make them yourself from cardboard or foil.
Don’t plant sunflowers too close together
Make sure that you do not plant the early sunflowers too close together. A maximum of four plants should grow on one square meter of soil.
When caring for sunflowers in pots or containers, always only put one plant in the container.
Otherwise the sunflowers will compete with each other for nutrients and will remain small and stunted.
Tips & Tricks
If you feed sunflower seeds to birds in winter, it is quite common for some seeds to fall to the ground. If the winter isn't too cold, some sunflower seeds will germinate on their own in spring.
