How To Grow Sunflowers

Starting from Seed

Before planting soak the seeds in a warm bowl of water overnight. This softens the outer husk and helps in germination.

Seeds can be planted directly into the ground after the last frost, 10 cm apart and 3cm deep or started indoors in seed trays. Using regular potting mix, place the seed about 3cm into the soil. Keep at a constant temperature of between 21-30C and the soil consistently moist but not over saturated. In about 1-2 weeks, seedlings will appear. Thin out the weaker saplings and once the hardy stock reaches 5cm high and all danger of frost is past plant outside.

Blooming from mid-July to mid-late September sunflowers will, as the name implies, need at least 8 hours of sun a day. Mature plants can adapt to drier conditions as their large root systems will seek out water underground but will still need about 3cm of water a week. When watering make sure to wet the root only. Spraying water on the leaves or blooms will encourage powdery mildew and other disease.

There are many varieties of sunflowers falling into three distinct categories. Before planting check the seed packet to discover which ones suit your garden the best.

Dwarf Sunflowers

These smaller sized sunflowers do great in pots and planters and are a great choice for gardeners with little space, only reaching 0.5 to 1 m in height.

Medium Sunflowers

Growing to a height of 3 metres these are the most sought after. Divided into single stem types producing only one flower per plant and branching stem varieties, which will produce more flowers off a central stalk over a longer bloom time.

Giant Sunflowers

These varieties can reach as high as 4 to 5 metres. Because of their impressive size planting against a fence or in the back of the perennial border is an absolute must.