How to Grow Sunflower
Sunflower At a Glance
Difficulty
Easy
Category
Flower
Sun Exposure
Full Sun
Frost Tolerance
Frost Tender
Cold Hardiness
Survives to 2°C
Plant Family
Asteraceae
Growing Season
Warm Season
Plant Lifecycle
Annual
How to Start It
★ Recommended for beginners
Sow about 1 week after your last spring frost, once the soil is warm. Push 2 seeds 2.5 cm deep every 30 cm and cover them. They sprout in 7 to 10 days: keep the strongest seedling at each spot and pull the other.
Sunflowers are one of the easiest seeds for kids and beginners: the seeds are big and the plants grow fast. They grow one long main root and do not like being moved, so sow them where they will bloom. Short kinds like Teddy Bear suit pots, while tall kinds need room and a stake.
When To Start
First chance to plant
7 Days After Last Frost
Last chance to plant
60 Days Before First Frost
When should you plant Sunflower?
Your planting dates depend on your local climate. Sign up and add your location to unlock personalized dates.
Your Sunflower Planting Window
Start planting
May 15, 2026
Last chance
Sep 10, 2026
Your Sunflower Calendar
Set your location to turn these into exact dates and reminders.
Sow sunflowers outdoors now that the soil is warm
1 week after your last frost· every year
Cut sunflower heads when the backs turn yellow brown
80 days after your last frost· every year· optional
Did you water your sunflower seedlings today? Keep the top of the soil damp until they are up and growing.
About 1 days after you plant it
Your sunflowers are shooting up! Water deeply and stake tall ones if they lean.
About 33 days after you plant it
Hi there! Keep watering your sunflowers well while the big flower heads form.
About 57 days after you plant it
Picking time may be here: check your sunflower.
About 70 days after you plant it
The Journey Ahead
Sunflower's Lifecycle
Seedling
Mature Plant
Seed Production
Step 2
Planting & Sprouting
Expect sprouts in 7–10 days
Growing Tips
- 1Give sunflowers your sunniest spot, with at least 6 to 8 hours of sun a day.
- 2Loosen the soil deeply and mix in compost so the long roots can push down.
- 3Water deeply about once a week, more often in pots and hot spells, and most of all once flower buds form.
- 4Feed once with compost tea or worm castings when buds appear, since too much food makes weak, floppy stems.
- 5Tie tall kinds to a sturdy stake, because a heavy head can snap the stem in wind.
- 6Cover seedlings with row cover to keep slugs and birds off until they are about 15 cm tall, and pick slugs off by hand in the evening.
Seedling Phase
Step 3
Growth & Maturity
~70
Days to Maturity
200 cm
Mature Height
60 cm
Mature Width
Pests to Watch For
Diseases to Watch For
Mature Plant
Step 4
Harvesting
Harvest Window
21 days
When to Pick
Cut seed heads when back of head turns brown
How to Harvest
- 1Cut flowers for a vase when the petals are just starting to open, and change the water often.
- 2For seeds, wait until the back of the head turns from green to yellow brown and the petals dry and fall.
- 3Cover ripening heads with a paper bag or mesh so birds do not eat the seeds first.
- 4Cut the head with about 30 cm of stem and hang it upside down in a dry, airy place for 1 to 2 weeks.
- 5Rub the dry seeds out with your hand, then eat them raw or roast them with a little salt.
- 6Or leave a few heads standing for the birds to feast on in fall.
Step 5
Saving Seeds
How to Save Seeds
Bees carry pollen between sunflowers, so different varieties grown together can cross, and hybrid F1 seeds will not grow true. To keep a variety pure, grow only that one kind in the season you save seed. Let the head ripen on the plant and dry it as you would for eating, then pick out the plumpest seeds. Dry them for another week on a plate. Store them labelled in a cool, dark, dry place, where they keep a few years.
Seed Production
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