Grow a Sunflower in a Pot

Sunflowers have many uses such as for producing biodiesel and cooking oil. But the best use of a sunflower is to brighten up your garden during the sunnier months of the year, or even to brighten the greenhouse or a sunroom any time of the year. This quick guide to growing a sunflower in a container is something even children can enjoy as a fast and fun garden project. Brighten your day with homegrown sunflowers.

Steps

Selecting a variety of sunflower

  1. Purchase sunflower seeds. You can obtain suitable sunflower seeds from a local nursery or garden center. Be careful about the variety you purchase, though, as only dwarf sunflowers are really suitable for container growing. Suitable dwarf sunflower varieties include (and as names vary, ask your local retailer for specific guidance in your region):
    • Pacino: this bright yellow sunflower grows to about 30 cm (12") in height.
    • Big Smile: this sunflower has yellow petals and a black center and grows to about 30 cm (12") in height.
    • Teddy Bear: this sunflower grows to about 40 cm (15") in height.
    • Sunspot: this sunflower has an amazingly large flowerhead (about 25 cm or 10 inches across) but is still a dwarf variety, growing to about 60 cm or {{safesubst:#invoke:convert|convert}} in height.
    • Music Box: this sunflower reaches about 60 cm (2 feet) and has lots of smaller flowers.

Preparing the container or pot

  1. Purchase or repurpose containers or pots that are suitable for growing the sunflowers in. The containers should be clean and sterile if you're repurposing them and don't forget to add saucers for catching the water. Gauge the size of the container needed according to the height of the flower you're planting, along with any other considerations such as how many sunflowers you'd like to grow per pot but some suggested sizes are:
    • If you begin in a pot with a very small radius, the sunflower will need to be transplanted fairly early on; some people do this to give the sunflower a head start while garden soil is still cold but be aware that sunflowers aren't very partial to being transplanted.[1]
    • 30 cm-40 cm or 12"-16" width containers for most dwarf sunflowers should be sufficient.[1]
    • Window or porch box - a deep window or porch box can be ideal for a row of dwarf sunflower seeds. You'll need to thin out weaker seedlings early on (explained below).
    • Large or mammoth sunflowers need containers of at least 18 litres or 5 gallons:
      • A milk crate can be used – just be sure to line it well or you'll have soil spillage.
      • Half a barrel for really tall sunflowers. Obviously this will need to sit on a sunny porch or in the garden unless you have a sunny spot free inside the house.
  2. Put the soil into the container, pot or window/porch box. First add a layer of drainage material, such as pebbles, gravel, terracotta pieces, or small pieces of polystyrene foam. Then pour in quality container soil such as a mix of compost and commercial soil mix. It should come to a level about 2.5 cm / 1 inch from the top of the container. Water it well.
    • Give consideration to adding water retaining crystals to ease the amount of watering required and to ensure that the sunflowers will get adequate amounts of water.
    • Adding well rotted compost is important as a source of food for the sunflower, so try to do this if you can.

Planting the sunflower

  1. Place the sunflower seeds in the container. Sow 2 to 10 seeds in pairs, depending on the size or length of the container you've chosen. Not all of the seedlings will be kept, so don't worry too much about squashing them in at this stage but do be prepared to discard all the weaker appearing seedlings later. When planting, plant 2.5cm (1 inch) deep and at least 10cm (4") apart.
    • It is possible to fit about 8 sunflower plants into a container length of 90 cm (3 feet), so using this as a guide, you'd plant around 16 plants in such a container and expect to thin out about eight.[2]
  2. Be prepared to water sunflowers more often than many other plants. Add about 25ml (0.83 fl oz) of water for every seed planted. Water once every one to two days in the same amount, depending on how moist the soil stays. Ensure that the soil is kept moist until the seeds sprout.

Caring for the sunflower

  1. Wait for the seeds to Germinate Seeds in Hydroponics. Germination should occur in the next three to eight days. If not, wait a little longer but by 13 days it is definite that the seed will not grow.
  2. If germination has been successful, then well done! After germination, thin out the weaker seedling of each pair and remove any diseased or malformed seedlings. If space is an issue, move to additional containers but remember that sunflowers don't thrive on being transplanted.
    • Keep Make Your Garden Water Wise as before until each sunflower is about a foot (30 cm) tall, at which time you should double the amount of water they have been receiving.
  3. Put the sunflower container in a nice sunny part of your house, garden or on the veranda (porch) if you prefer. A sunflower should be positioned so that it gets full sun all or most of the day; no sunflower can handle shade for most of the day. If you have the sunflower growing indoors, choose a sunny room but avoid placing it too close to a window because air near windows is often hotter or colder than the room temperature and this can be harmful to the plant.[3] Try to keep the container away from extreme rain.
  4. Continue to tend the plant with water and general plant care. In two weeks the Paint a Sunflower should now be a decent size.
  5. At this point give the sunflowers {{safesubst:#invoke:convert|convert}} (2.5 fl oz) of water. The sunflower buds should now be just showing.
  6. Fertilize if wished. While sunflowers don't need additional feeding, giving them extra nutrition can give the flowerheads a boost. Apply a ready-made, branded general purpose plant fertilizer (follow the directions on the container for flowers) or an organic fertilizer like vermicompost or home made kitchen compost.
  7. In one month the sunflower bud should be still developing for the next two weeks (water regulation should increase to 100ml/ 3.3 fl oz of water). The bud should just be ready to bloom.
  8. Enjoy the sunflower as a decorative element in your home or wherever else you've placed the container. In many cases, you will find that the sunflower becomes top heavy and needs to be staked up to hold the glorious flowerhead up high. A simple bamboo or similar stake with plant ties will be sufficient to keep the sunflower's head up high. However, this should probably be anchored to something other than the pot unless you're absolutely certain the pot is strong enough to hold without falling over.[1] You might tie the stake to a wall pipe, a bookcase frame, or similar objects inside the house, or to the drainpipe, wall or other objects if outside. Be aware that not all sunflowers require support – simply observe how your sunflower is coping on its own before deciding.

Harvesting

  1. If you want to make culinary use of the sunflower, the petals from the flowers make a pretty addition to salads, and both the seeds and the buds can also be eaten.
    • To get the seeds, you have to let the flower die on the plant and just wait. As the flower dries out, the seeds ripen and dry too. While this isn't very pretty, at least the birds can't take the seeds if you've got your sunflower indoors!
    • If eating the buds, blanch them first to remove bitterness, then steam or boil for three minutes. They are delicious tossed in garlic butter.

Tips

  • The bigger the pot, the bigger the sunflower, especially if you're not growing dwarf varieties.
  • Once your seedling has sprouted, (within 2 weeks) make sure it gets as much sunlight as possible. As it grows, you will need to increase the amount of water your plant receives.
  • Once your plant is big enough, it may not grow straight and you may have to tie it to a light stake.
  • If sowing sunflowers in the ground, the earlier you sow them, in late, spring, the sooner they'll flower. For container gardening, provided you have a sunny place for them, they can be grown year round.
  • If you want seeds, let the flower die on the plant, and when the seeds are hard, you can remove them and boil them.
  • Sunflowers are native to North America and are grown as tall annuals in the garden.
  • Spray the flower head regularly with water.

Warnings

  • Keep the soil moist, not too wet, or the plant may rot.
  • Make sure that the pot has drainage holes or the seed risks rotting.
  • Mammoth sunflowers (the ones that grow over 180cm or 6 feet) are not suitable for container growing unless you are using a very big container, such as the half barrel. If you force such sunflowers to grow in a smaller container, they are unlikely to thrive and you may even see the entire sunflower growth process occur in a totally stunted form (which is fairly sad to watch since such a magnificent flower never reaches its full potential).

Things You'll Need

  • Sunflower seeds from a nursery in packets with identifying labels - Note: while you could try to grow the seeds you buy to eat from the supermarket, the type will be unknown and they may not be fertile anyway. Do not try to grow sunflower seeds without a shell as removal of the coating exposes them to air and light and definitely do not try to grow any that have been roasted or salted
  • Water
  • A clay pot or other suitable round container (30cm/12" diameter minimum for a pot, wider if adding lots of seeds); or, a window or porch box, milk crate, half a barrel, etc. as preferred, all wide
  • Soil
  • Rotted compost for nutrition
  • For enhanced drainage, add some rocks at the bottom

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