When to sow sunflowers?
- Botanical name
- Helianthus annuus
- Family
- Asteraceae
Sunflowers are sown from May to June. They flower from July to September.
Sunflowers are annual plants. The edible parts are the flowers and seeds.
A tall stem that once dries out never recovers, so the watering is regular. The ground around it is covered with mulch, with some space left at the stem, so that the base does not rot.
The stem with the ripe head can be left standing, because birds feed on the seed. Part of the seed is kept for a spring sowing, because a sunflower does not come up again the next year.
Sunflowers through the year
- sowing
- planting
- flowering
In short
The last frost is not on the same day everywhere, so the recorded weeks are a guide and not a date.
Growing conditions
Are sunflowers toxic to cats and dogs?
No. Sunflowers are not toxic to cats and dogs.
Companions in the bed
Companion planting is tradition and not an agronomic claim. What is recorded is which pairs sources recommend and which they advise against.
The sunflower is a living support instead of a pole. It works only if it is sown a few weeks earlier.
The sunflower as a living support. It works only if it is sown a few weeks earlier.
- “Cited” means the pair is named by one source or two.
Pests and diseases
Listed here is every problem for which the sources name this plant as a host. The problems are not listed in order of how common they are.
- Signs
- A white, floury coating spreads over the leaves, first on the lower and older ones. The leaf under it yellows and dries up. The fruit stays small, because the plant loses leaf surface.
- Prevention
- Plant resistant varieties, leave an airy spacing and sun, and clear the debris at the end of the season. Unlike most fungi it is not helped by wet foliage, since it spreads in heat and high air humidity, in a dry summer too.
- What to do
- Oil products meant for powdery mildew on the squash family work on contact. They do not cure a leaf that is already affected, but they stop the spread to healthy ones. On herbs cut the affected shoots back instead, since the new growth comes clean. On ornamental perennials what is left is spacing and moisture.
- Signs
- Holes appear in the middle of the leaf rather than along the edge, young plants are eaten down to the ground, and there are slimy trails in the morning. On low-growing fruit there are gnawed pits.
- Prevention
- Remove the hiding places beside the bed: boards, stones, dense weeds. Water in the morning and not in the evening, so that the night is dry. Spread a band of coarse sand or gravel around the bed. Cover young plants with fleece. Pick them off at night, which is still the most effective measure.
- What to do
- Baits with iron phosphate are held to carry less risk for pets and children. Put them out in bands beside the bed, not scattered over the whole surface.
Check the registration and the label before use.
Keep track of your plants with Tendask
Log the task and set a reminder for the next one. Every plant keeps its own history, so there is nothing to guess at.
Related plants
The plants below are in the same botanical family (Asteraceae).
Sources about the plant: ASPCA Toxic and Non-Toxic Plants, Clemson Cooperative Extension, GBIF Backbone Taxonomy, NC State Extension Plant Toolbox, Royal Horticultural Society, Utah State University Extension, Wikidata. Checked between 14 and 28 August 2026. The problem descriptions also draw on: KGZS, UF/IFAS Extension, University of Maryland Extension, University of Wisconsin-Madison Division of Extension.