It’s entirely possible to grow sunflowers in pots! But take a realistic approach to this plan. Don’t try to plant giant varieties in a pot for your deck; you’d need a pot more than 6 feet deep to accommodate the deep taproot the giant sunflowers put out. Instead, consider growing dwarf varieties, which grow to no more than 3 feet tall. Not all the dwarf varieties have the classic sunflower shape, so look closely at the varieties if you would like to harvest the seeds at the end of the season. The Sunspot variety looks just like a giant sunflower, except that it grows on a dwarf plant.
To give your potted sunflowers the best chance at full, healthy growth, put your container on a wheeled base. This will make it easy for you to move your plants so they get their full daily dose of sunshine.
Remember that potted plants dry out more quickly than plants growing in open land or raised beds. But be sure not to overdo the water; the last thing you want to do is kill your sunflowers with kindness. Make sure your container has good drainage, and don’t let you sunflowers get soggy wet feet!
You can apply a light side dressing of balanced 5-5-5 fertilizer when your sunflower plants’ first true leaves develop. The next time they’ll need a feeding is when the flowers begin to develop. Once the flowers bud, nitrogen is not essential. If you do add nutrients once the flowers emerge, blood meal and fish emulsion are good choices.
Have you grown sunflower plants in pots? How has that worked out for you? Please share you tips for successfully growing sunflower plants in containers.