Horticulture Magazine

How To Grow Sunflowers In Pots

sunflowers growing in terracotta pots

Sunflowers are cheerful and useful flowers to grow in your garden, and they can also grow in pots.

Planting sunflowers can be a fun activity for the whole family to enjoy.

The large seeds are easy for children to handle – and since the sunflowers grow quite quickly, kids and novice gardeners do not have to wait too long to see the results of their efforts.

This guide is written for those wishing to grow in garden containers – if you’re planting sunflowers in the ground, check out this care guide for better-suited advice.

Potted Sunflower Varieties

sunflowers growing in pots with a wall in the background

If you plan to sow and grow sunflowers in pots rather than in the ground, it is best to choose smaller varieties.

The tallest and most vigorous sunflowers will do best when grown in the soil in your garden.

Fortunately, however, there are plenty of great options to choose from.

We would recommend considering dwarf, branching sunflowers, which produce not just one single flower head, but multiple flowers on the same plant.

These will offer you the best value in your container garden, and be great for bees and other wildlife.

small potted dwarf sunflowers

Though traditional single-headed sunflowers can also be grown in pots and even tall sunflowers can be grown in containers of sufficient size.

Some interesting sunflowers to consider growing in containers include:

  • Little Dorrit
  • Pacino Gold
  • Dwarf Sunspot
  • Waooh
  • Sun Tastic
  • Little Leo
  • Dwarf Yellow Spray
  • Big Smile
  • Ms Mars
  • Teddy Bear

Choosing Pots For Sunflowers

a round container with sunflower seedlings

You can start out sunflowers in small containers.

There are a range of reclaimed materials that you can use to make this a really cheap and eco-friendly project.

You can sow your sunflower seeds in toilet roll tubes, small scrap paper pots, or yoghurt pots, for example.

One other fun thing to consider is having kids make their own starter pots for sunflowers from papier-mache (scrap paper/flour glue) or cardboard boxes.

sunflower seedlings growing on a windowsill in an old egg carton

Then you can pot up your sunflower seedlings into larger containers; again, a range of reclaimed materials can be considered.

The size of container that you will need for your sunflowers will depend on which variety (or varieties) you have chosen.

Smaller dwarf sunflowers that grow to around half a metre tall can be grown in a 25-30cm pot.

small sunflower head with bright yellow petals and foliage in the background

Taller specimens will need a larger container – 5 gallons or even bigger for the most vigorous varieties.

So when choosing a container, make sure you understand how large your sunflower will eventually grow.

Make sure that many containers you choose allow water to drain freely through the base.

Sunflowers do not like to have a saturated growing medium around their roots.

Filling Your Containers

two plastic pot grown sunflower plants on a balcony

Once you have chosen your starter pots and longer-term containers, and have the seeds for your sunflowers ready, you should fill the pots with a multi-purpose peat-free potting soil, or a mix of homemade compost.

It can also be a good idea to add some crocks (broken pot pieces) or gravel to the bottom to aid with drainage in the larger containers into which your sunflower seedlings will be placed.

Sowing Sunflower Seeds

sunflower seedlings growing from a plastic propagation tray

Sunflower seeds are best sown indoors, in April, to give the plants a good head start.

  1. Place two seeds into each starter pot, pushing each one around 2cm down into the growing medium, then gently covering them over and watering them in.
  2. Keep the growing medium moist and seedlings should emerge within around 7-10 days.
  3. When the seedlings emerge, make sure that you water every day.
  4. Remove the weaker seedling from each pot by snipping them off at soil level so you do not disturb the roots.
  5. Grow on in the starter pot and then transplant into the larger container once they have grown more and are ready to be placed into their final growing positions.

If you have used a biodegradable starter pot, you can simply place this within a larger container.

This is a good idea because it minimises root disturbance – but it is not essential.

heads of sunflowers with balcony in background

Sunflowers are generally very forgiving and you do not need to be too precious.

Move your sunflowers in pots outside as soon as all risk of frost has passed in your area.

Placing Sunflowers In Containers

Sunflowers in pots should be placed in a sunny and sheltered location.

They should be out of strong winds, with as much light as possible.

Make sure you choose a spot that gets at least 6 hours of sun each day.

a massive sunflower garden in plastic pots

Often, sunflowers will be grown in their own specific pots, but smaller dwarf sunflowers could also be grown in larger containers or planters alongside other annual flowers.

Even when growing in pots, it can also be a good idea to think about the benefits that sunflowers can confer on other plants.

They can be a great companion for a number of common crops in a fruit and vegetable garden, for example.

helianthus growing from a terracotta pot

Place sunflowers in pots close to fruiting plants like tomatoes to draw in pollinators and other beneficial insects.

And note that sunflowers can be useful as a trap crop for aphids and other sapsuckers.

Ants may sometimes herd aphids onto sunflower stems and this can keep them away from your main edible crops.

Caring For Potted Sunflowers

Caring for sunflowers in pots is very easy, but one thing that you do have to remember is that sunflowers are pretty thirsty plants.

Watering

a wilted helianthus flower with drooping petals

They will need plenty of water through the summer months.

When growing them in pots rather than in the ground, you will need to water more frequently and keeping the growing medium moist will be even more important.

Feeding

hand shown watering sunflower plants

Sunflowers grown in a good quality compost/potting mix may not need additional fertilisation.

However, to keep your flowers as healthy as possible and get them to grow to maximum size, you should consider feeding your pot-grown plants with a potassium-rich liquid plant feed.

An organic liquid feed like comfrey tea which is suitable for tomatoes will also suit sunflowers very well.

Support

bamboo canes used to support helianthus plants growing upright, with a garden wall in the background

If you are growing taller sunflowers, a cane or branch pushed into the container will give it the support it needs.

Place this before planting the sunflower itself to avoid damaging the roots, and tie the sunflower gently into this support as it grows.

Protection

magnified view of slugs eating the yellow petals of a sunflower

Sunflowers can be very appealing to slugs and snails.

You may wish to take steps to protect your sunflowers in pots from these pests, especially while they are young and vulnerable seedlings.

You might place copper tape around the edge of a pot, for example, or sprinkle crushed eggshells around the base of the plants.

But the best way to manage slugs and snails in the garden is to make sure you attract plenty of beneficial wildlife.

Attract creatures that eat slugs and snails to your garden and this will help keep their numbers down.

Saving Seeds

collecting sunflower seeds from a plant into an open hand

If you are growing a heritage sunflower, you can save the seeds for next year.

H1 hybrids will not typically come true from seed (they will be different from the parent plant).

However, you can still save the seeds to plant next year and you may see new and interesting variations.

After flowering, each flower head will produce abundant seeds.

open palm of a hand showing sunflower seeds

Save some to plant next year and remember, you can also eat some too.

This is a useful edible yield from this plant usually grown for ornamental reasons.

However, you should also consider leaving some seeds to feed the finches and other seed-eating birds in your garden.

Growing sunflowers is an easy and fun thing to do, and if you have not gardened before, growing some sunflowers can be a great place to start.

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