Sunflowers are one of the brightest (and tallest) flowers around and instantly add bold color to dull gardens or outdoor spaces. In addition, it is one of the easiest flowers to grow, so it will not be difficult to learn how to plant sunflower seeds and when to do it.
Otherwise known as Helianthus, the sunflower is native to North America and has more than 70 different varieties. Sunflowers are also known to reach giant heights of up to two meters, and they come in a wide range of colors including rust red, orange, green and even white.
The best time to plant sunflowers is between April and May, or when the soil warms up. While most sunflowers germinate once the soil reaches temperatures of 70 to 80 degrees F, you can sow the seeds first in pots or directly in the garden. Plus, learning how to plant sunflower seeds and watch them grow is fun for kids.
So if you want to add warmth and vitality to your outdoor spaces, here’s how to plant sunflowers from seed.
How to Plant Sunflower Seeds in Tubs or Pots
What you will need
Seed trays or pots
Gardening trowel or fork
Plant label and pen
1. Prepare your seed trays/pots — First, fill the seed tray with multi-purpose peat-free compost, leaving 1cm at the top. Place one seed in each seed pot and push gently into the compost. If you are using a seed tray, space the seeds about 5cm apart.
2. Place in a sunny place — Lightly cover the top with additional compost before watering well with a watering can. Add a plant tag before placing the tray in a warm, sunny location. Sunflowers thrive in the sun, so it’s best to place them near or on a windowsill.
3. Transfer to larger jars – Once your seedlings have germinated and reached a height of 2 inches, carefully remove each seedling and transfer them to larger individual pots. Add more compost to the pot to secure the seedling. If you have trouble getting the seedling out of the seed tray, use a knife or dull implement to gently loosen the soil.
4. Water well and transfer — Once your plants have reached 12 inches in height, you can plant them outside in a sunny spot or move them to a larger pot if you don’t have garden space.
TOP COUNCIL: Water the sunflowers regularly and do not let them dry out. You can also fertilize sunflowers once a week to promote growth.
How to plant sunflower seeds in the ground
1. Choose a well-lit area — First, find a sunny, well-drained spot in the garden before preparing the soil. Remove all weeds and rake the soil to a fine, crumbly texture.
2. Prepare the ground — Dig small trenches in the ground about 2.5 cm deep for each sunflower seed, leaving a space of 10 cm between each one. Then place a seed in each hole and cover with soil.
3. Water the seeds well — Water thoroughly with a watering can. Make sure the seeds stay well watered until they start to germinate.
4. Support rods – When the sunflowers start to grow and get taller, use stakes or canes to support the stems by tying them loosely with twine. This will protect the plant from strong winds and keep the stem strong and upright.
TOP COUNCIL: If you like the sight of sunflowers, sow a few seeds every two weeks. You will then have bright and cheerful flowers from the beginning of summer until the end of autumn.
How long do sunflowers take to grow?
Generally, it takes between 80 and 120 days for a sunflower plant to grow and develop seeds. But this will depend on the variety of sunflower and the conditions, as each type will grow at a different rate.
If you’re also interested in houseplants, check out our guides on how to care for succulents and how to repot succulents. We also cover how to care for air plants.
If you have favorite plants that are wilting, check out our top tips on how to save a dying plant. Also be sure to check out these 5 plants that can help you sleep better, as you learn how to clean every room in your home for spring cleaning tips.