Sunflowers are big, irresistible summertime flowers. If you love the idea of growing some of the showy bloomers but you don't have enough gardening space to accommodate the big plants, take heart. Sunflowers are easy to plant in pots, and once started, require very little care. Simply start sunflowers indoors two to three weeks before the last frost, and move them to a sunny location on your patio or balcony when the weather warms up in spring. Although tall sunflowers can be grown in containers, small varieties may be more manageable.
Purchase a packet of sunflower seeds. Read the packet to determine the eventual size of the plant. Dwarf varieties such as Music Box, Teddy Bear or Sunspot will reach heights of less than 3 feet at maturity. Velvet Queen, Autumn Beauty and others are mid-size, reaching about 6 feet. Skyscraper and Dove sunflowers can grow to heights of 8 to 12 feet.
Fill a pot with commercial potting soil. Allow 1 to 2 inches unfilled at the top of the pot to allow for watering. The pot should be a minimum of 15 inches deep and must have at least one drainage hole in the bottom. Use larger containers with sturdy, wide bottoms for tall varieties of sunflowers, as the sunflowers will be top heavy and can easily tip over.
Water the potting soil with a watering can or a hose with a spray attachment. The potting soil should be moist clear through, but not dripping, as too much moisture will cause the sunflower seeds to rot.
Plant sunflower seeds in the potting soil. The seeds should be planted an inch deep and about 6 inches apart.
Place the sunflower outdoors in full sunlight as soon you're sure any danger of frost has passed. The sunflower should be located where the plant will be protected from strong winds.Turn the container at least once every week so all parts of the plant will be exposed to equal amounts of sunlight.
Place a wooden stake in the soil when the sunflower grows about 10 inches tall. The stake should be slightly shorter than the mature size of the plant, and will keep the stem upright.
Keep the soil moist, but don't over-water. Check the container daily, especially after moving the container outdoors, as potting soil in containers will dry out quickly, especially during hot, dry weather.