The most fascinating sunflowers you will ever grow will produce their buds and blossoms close up, at eye level, showing you their intricate geometry. Then, you get front row seats to watch bees and other pollinators visiting the flowers, followed by the finch finale as the seeds are plucked out the day they become ripe. To stage this great show, all you need to do is grow sunflowers in containers on your deck or patio.
After my local deer developed a taste for sunflowers, I began growing them in pots on my deck because it was the only way to have them. I knew it could be done, because some gardeners in the US grow potted sunflowers to use as trap crops for leaf-footed bugs or stink bugs. When positioned near cucumbers, peppers or tomatoes, blooming sunflowers may lure away pests that would damage the ripening fruits.
I quickly learned that huge pots are not needed for sunflowers, which have an amazing ability to adapt to containers of various sizes. Containers have a dwarfing effect on most plants, and sunflowers grown in pots become miniature versions of their true selves, producing much smaller leaves, stems, and flowers. For example, the fluffy ‘Gummy Bear’ variety will grow to 42 inches (106cm) in the garden, but in pots the plants bloom when less than 16 inches (40cm) tall and produce half-size flowers.
Best Sunflowers for Containers
Except for giant or mammoth types that produce plate-size blossoms on towering plants, most sunflowers are easy to grow in containers. There are differences between varieties that produce one flower on an upright stem and branching types that produce smaller flowers over a longer period of time. I suggest trying both types. You can start seeds outdoors in small containers, and move them to larger pots as they grow.
One advantage of single-flowered varieties like ‘Sunspot’ or ‘Procut’ is that they grow quickly, often blooming after only 60 days, and the large buds are beautiful to watch as they bulk up to bloom. Branching varieties like ‘Velvet Queen’ or ‘Autumn Beauty’ tend to grow taller and take longer to commence flowering, and then bloom for several weeks. They make great cut flowers.
Best Containers for Sunflowers
They may not be pretty, but plastic pots hold moisture well and weigh very little, so they are perfect for growing sunflowers. As blossoms appear, you can slip the whole thing into a prettier planter. Double pots provide places for pests to hide, so stick with single pots while plants are young.
Water pot-grown sunflowers daily in hot weather. Plants that show droopy leaves after the sun goes down are seriously parched, and may need to sit in a pan of water to rehydrate.
Sunflowers are heavy feeders that respond well to high levels of nitrogen. Regular feeds increase leaf and flower size and help keep plants growing fast. Fertilise potted sunflowers with a water-soluble plant food every two weeks, starting when seedlings have four or five leaves.
Troubleshooting Potted Sunflowers
When you find holes in the leaves of potted sunflowers, the culprits may be earwigs, greenhouse millipedes, or night-flying moths and beetles. Check beneath containers for earwigs and millipedes. Sweep either pest away, and set out oil traps to collect earwigs that return to the scene of their crime at night. To reduce issues with nocturnal visitors, position plants well away from lights that are frequently used at night, including solar lights.
Don’t worry if the lowest leaves turn yellow and die as the plants grow. This is normal with sunflowers, but often not noticed when plants are grown in the garden. When you grow sunflowers in containers, you notice everything.