Tips on How to Grow Sunflowers From Seed
The sunflower (Helianthus annuus) is a fascinating plant to grow, especially for children. Whether growing for competition or pleasure, exercising the following advice will help provide your sunflowers with the best conditions for good growth and health.
Selecting A Sunflower Species To Grow
The first step in growing sunflowers is deciding on the species you wish to grow. There are 67 species of sunflower across the world with single or multiple stems, growing heights, head sizes and colours. Read through the details of each popular species below to help make an informed choice on the sunflower you plan to grow.
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Music Box is what’s know as a dwarf variety, growing to a maximum height of 28 inches, making it suitable for container growing.
Teddy Bear species of sunflower smaller than Music Box, growing to around 12 – 18 inches.Italian White sunflowers, also a small variety but with an attractive cream coloured flower.
Autumn Mix unlike the above, normally grows over 6ft in height with yellow and rust coloured flower head, 5 – 6 inches in diameter.
Largest Sunflower Species such as the Russian Giant grows in excess of 15 feet tall with a large head diameter up to 20 inches. Obviously, larger sunflower species will demand more space than the other species mentioned previously. Great fun if you have room to grow them though.
What’s The Best Location For Growing Sunflowers
Grow sunflowers in soil exposed to direct sunlight and sheltered from wind. Protect your sunflowers by supporting the stem with a bamboo stake as soon as the sunflower reaches 1ft in height. This will help the stem grow straight and protect the sunflower from wind damage.
When the sunflower matures, the heavy weight of the head on the tall stem leaves the sunflower vulnerable to wind damage. Because wild sunflower only grows between 2 and 6ft in height, the risk of wind damage is far less than that of the domestic sunflower.
What’s The Best Soil For Growing Sunflowers
Plant your seedlings in good quality soil such as my personal favourite – Miracle Grow potting mix which has good water retention, enriched with plant food. Always ensure soil is kept moist and prevent it from drying out completely. Consider adding manure to the garden soil where you intend to plant your seeds or seedlings.
Tips For Germinating Sunflower Seeds
If you prefer to germinate your sunflower seeds before planting in soil, layer at least 10 sheets of absorbent kitchen roll paper towel placed on a plate then soak with water. Sprinkle seeds evenly over the wet paper towel before placing them in a warm space such as an airing cupboard. The more sheets of paper towel you use, the better the water holding capacity, meaning less frequent watering will be required.
Checking seeds with regular watering will prevent the paper towel from drying up, especially common in warm environments or direct sunlight. When your sunflower seeds begin to germinate, plant into potting compost mixed with manure into your garden at a depth of 2 inches, spaced 1 – 2ft apart.
Sowing Sunflowers Seeds In Pots
If you’re germinating your sunflower seeds in pots, sow a single seed in each pot at a depth of 1 inch in 3 inch diameter pots. Use good quality potting compost such as Miracle Grow potting mix, before covering the top of the pot with clear cling film.
When green leaves appear above the soil after germinating, remove film and place pot near a window that gets the most sunlight throughout the day if possible. Turn the plant pot 180 degrees in the morning and again in the evening, checking to ensure the soil is kept moist.
If the pot was too small or the sunflower has been left in the pot too long, there will likely be a heavy build up of roots around the walls of the pot. Because sunflowers have long taproots capable of growing 4ft deep, allowing the plant to reach this stage in pots will severely hamper growth.
Overcrowded roots can be safely removed by cutting off no more than 1/3 with a sharp knife. Break away and discard dead soil surrounding the roots of the sunflower before planting in the garden. Remember to take care not to damage the remaining healthy roots in the process.
Sowing Sunflower Seeds In The Garden (Recommended)
Sowing seeds directly into the garden is my preferred method in which I have had the most success. Sow your sunflower seeds after the last winter frost has passed and night temperatures have raised to over 5º or 10º Celsius. Sow in loose soil at a depth of around 50mm (2 inch) spaced 1 – 2ft apart. Water seeds regularly until 2ft high when the second set of leaves appear. Liquid fertiliser should be added to the water for feeding from this point forward.
Sunflower Facts
- The sunflower (Helianthus annuus) is a fascinating plant to grow, especially for children. Sunflowers can grow up to 12ft high with a head diameter of up to 30cm (1ft).
- The head of the sunflower, often erroneously referred to as a flower, consists of 1000 – 2000 individual flowers. The petals surrounding the head are ray flowers.
- Sunflowers are one of the fastest growing plants in the world, growing up to 30cm (1ft) per day.
- A fascinating characteristic of the sunflower is its ability to track the direction of the sunlight by pointing the sunflower head towards the sun. This behavior is referred to as heliotropism.
- Wild sunflowers have smaller seeds, growing several branches and/or stems with more than one head. It is only through hundreds of years of careful, hand-picked seed selection is the domestic sunflower much larger with a single stem and flower head.
- The sunflower is the state flower for Kansas, USA and the national recognised flower for Russia.
- According to the Guinness Book of World Records, the tallest sunflower ever grown was in 1986 by M Heijms in Oirschot, Netherlandsat a height of 25ft 5.5 inches (776 cm).
- The largest sunflower head ever recorded by the Guinness Book of World Records measured 32 1/4 inches (82 cm) in diameter, grown by Emily Martin from Maple Ridge, Canada in the hot summer of 1983.
- Although native to America, 60% of the world population of sunflowers are grown in Europe and Russia. Popular species with sunflower growers starting with the tallest: Moonwalker, Pastiche, Velvet Queen, Russian Giant and the smaller Teddy Bear and Big Smile species.
- Sunflowers are very effective for attracting butterflies, bees and birds.
- Sunflowers are used to produce sunflower oil. As a seed, they are used for bird feed and as a healthy snack for children and adults.
- Sunflower seeds have a 50% polyunsaturated fat content and are rich in Omega-6 which has been proven to reduce the risk of cardiovascular disease. Sunflower seeds are rich in calcium along with a number of other vitamins and minerals.
- The scientific name for sunflowers; Helianthus derives from two Greek words, Helios meaning sun and Anthos meaning flower.
- Sunflowers are perennial plants that grow each year.
- Sunflower seeds are toxic to grass so distance them from your lawn which would be killed by falling seeds.
Sunflowers: An Excellent Choice For Kids Sunflowers are an excellent choice of plant for children to grow. They are visually appealing, attract a range of insects such as butterflies, bees and birds in addition to being easy to grow.
You may be able to encourage friends or neighbours to compete with, seeing who can grow the tallest sunflower. I personally have fond memories of being a 9 year old child, competing with my next door neighbour. If my memory serves me correctly, I managed to grow three sunflowers at a height of about 6ft. Although being so young, everything seems bigger at that age, so I may well be wrong. I know, I shouldn’t boast, but naturally I did win…. naturally of course.:) Sorry!!
The BBSRC (Biotechnology and Biological Sciences Research Council… phew) have produced a sunflower growing activity ebook for young children to grow their very own sunflower, whilst learning how plants grow.
Sunflower Plant Care
Sunflowers need plenty of watering and sunlight, taking approximately two weeks to appear and 90 days to fully grow. If using chemical weed killer, make sure it is suitable for use on sunflowers or pull weeds out by hand. Over-watering sunflowers will likely damage flower heads, particularly 20 days before or 20 days after full bloom.
Pour around 2 gallons of liquid fertiliser solution each week around the roots of the sunflower, taking care not to pour the solution over the stem as this has been found to cause sunflower stems to rot.
Try to position your sunflowers so they spend as much time in the sun as possible, preferably 6-8 hours or more. If heavy winds are forecast, put off watering until the wind has passed to prevent the sunflowers from getting blown over.
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