Sunflowers are beautiful if grown outside in your garden, and the seeds are nutritious and delicious for people and birds alike. But what if you want to grow them in containers, either indoors or outdoors on your patio? I did some searching to find out if this is possible, and the best practices for doing so.
So, can you grow sunflowers in pots? Yes, you can grow sunflowers in pots. You should use a pot that is at least 18 inches (46 centimeters) wide by 18 inches deep. For sunflower varieties taller than 3 or 4 feet (1 meter or so), you should support the plant with stakes as it grows.
Although you can grow sunflowers in pots, there is more to take into account, such as the soil you use and how much water or sunlight your plants get.
Can You Grow Sunflowers In Pots?
You can grow sunflowers in any type of container including grow bags, raised beds, and of course, ordinary gardening pots. You can leave the potted sunflowers either indoors or outdoors. But just how big should a pot be to grow sunflowers?
How Big Should A Pot Be To Grow Sunflowers?
The size of the pot you need to grow a sunflower will depend on the variety that you choose. For most varieties, you should be safe with a pot that is 18 inches (46 centimeters) wide, although some sunflowers have a spread of 24 inches (61 centimeters) or more.
As far as depth, a pot that is 18 to 24 inches (46 to 61 centimeters) deep should be sufficient for most varieties, since sunflower roots grow 1 to 3 feet deep.
However, you may want to choose a deeper and wider pot with more volume for larger varieties. Remember, some sunflowers can grow to a height of 6 feet or taller! These will require more weight in the pot to keep them from falling over as they grow, so plan accordingly.
Here are a few different varieties of sunflowers in each height category:
- Short: Ms. Mars – this sunflower has dark red or purple coloring in the flower and stems. It will grow to a height of 20 to 30 inches (51 to 76 centimeters), and will spread out to a width of 18 to 24 inches. For something a little different that won’t grow out of control indoors, check out Ms. Mars Sunflowers on Burpee’s website.
- Medium: Sunny Bunch – this sunflower has the usual yellow color you would expect on the flowers, and it grows to a height of 24 to 36 inches (61 to 91 centimeters). This sunflower only spreads out to a width of 12 to 16 centimeters, making it nice and compact for small indoor or garden spaces. For more information, check out Sunny Bunch Sunflowers on Burpee’s website.
- Medium: Busy Bee – this sunflower also has the usual yellow color of sunflowers, the same as Sunny Bunch. However, Busy Bee sunflowers grow a bit taller, from 36 to 48 inches (91 to 122 centimeters) tall. The spread of this sunflower is only 12 to 16 inches, making it another great choice for small areas where you need a compact plant. Check out Busy Bee Sunflowers on Burpee’s website.
- Tall: Del Sol Hybrid – this sunflower matures early, just 50 days after planting, and it has the usual yellow color of sunflowers. However, it can reach a height of 60 to 72 inches (152 to 183 centimeters), making it a great conversation piece if you can grow it indoors. The spread of this sunflower is only 8 to 12 inches, making it super compact – it probably won’t go outside the boundaries of its pot if you stake it properly! For more information, check out Del Sol Hybrid sunflowers on Burpee’s website.
Your choice of sunflower variety will depend on how much space you have available in your home (vertical as well as horizontal!) or garden. Remember that sunflower seeds can be a great distraction to keep birds away from other plants that you value more, such as berries.
What Type Of Soil and Fertilizer Does A Sunflower In A Pot Need?
As with most plants, sunflowers will do best in loose, well-draining soil. You can buy a potting mix containing perlite or vermiculite, or create your own. If you’re not sure which to use, check out my article on perlite and vermiculite.
The soil pH should be between 6.0 and 7.5 (slightly acidic to slightly basic). For more information on growing conditions, check out this article on growing sunflowers from the Old Farmer’s Almanac website.
If you are using your own compost or soil from your yard or garden, make sure to test the soil if you are worried about pH or nutrient imbalances. For more information, check out my article on how to do a soil test.
Plant your sunflower seeds 1 to 2 inches deep in the soil. Then, keep the soil moist for the first week or two until the seeds germinate. Start the seeds right in the pot, since sunflowers do not tolerate transplantation very well.
As your plant grows, be sure to provide fertilizer if needed – sunflowers are heavy feeders. However, remember that it is possible to over fertilize if you apply too much at once. For more information, check out my article on over fertilizing plants.
How Much Water Do Sunflowers Need?
As mentioned before, keep the soil in the pot wet for the first week or two until germination. Then, you can let up on the watering a bit, since you don’t want to cause root rot by keeping the soil constantly wet. For more information, check out my article on over watering your plants.
Remember that the soil in pots dries out much faster than the soil in the ground. This means that you cannot forget about your potted sunflowers for as long as you could your ordinary plants outside.
Also keep in mind that clay and plastic pots have different properties as far as how much water the soil will retain. For more information, check out my article on clay versus plastic pots.
How Much Sunlight Do Sunflowers Need?
Sunflowers will do best if they have direct sun, meaning 6 to 8 hours of sunlight per day. If your plants are indoors, put them near a window where they will get the most sun (in the northern hemisphere, this is the south side of the house).
For outdoor plants, you can put the pots anywhere that is not too shady due to trees or structures like sheds, barns, or your house. If your yard is shady, try putting the pots somewhere on the south facing side of the house.
How To Support Sunflowers As They Grow
Many of the short and medium varieties of sunflowers will only grow to a height of 2, 3, or 4 feet. These may not need any support at all, although there is nothing wrong with staking a 4 foot tall plant.
The taller plants that grow 5 to 6 feet or taller will almost certainly need support if grown in a pot. For one thing, the height of such a sunflower means that the entire pot is more likely to tip over as it grows.
Also, if you are growing outside, tall sunflowers without support are more likely to be blown over in a gust of wind or a storm. For more information, check out my article on protecting your plants from wind and storms.
For sunflowers that are 5 to 7 feet tall, you can drive a stake (such as bamboo or metal) deep into the soil inside the pot that the sunflower is growing in. Make sure to do this before planting the seed. If you do it when the plant is established, you can harm the roots.
Then, use twine to tie the sunflower to the stake at intervals as the plant grows, using twine (don’t tie too tight!)
For taller, heavier sunflowers, you may want to put additional weight in the pot to keep the whole thing from falling over. Choosing a larger pot and filling it with soil is one way to do this.
You can also choose a heavier pot made of metal or ceramic to add extra weight. You can even put some stones on top of the soil to add weight and keep the pot from falling over.
If you are still worried that the pot, stake, and sunflower setup will fall over, then get yourself another pot. Put the pot right next to the first one with your sunflower. Fill the second pot half way with soil and stick a stake into the soil.
Then, fill the pot the rest of the way with rocks. Finally, use this second stake as extra support to hold up the sunflower and keep it from falling over.
If you have another short plant that you want to grow that doesn’t need support, you can put it in the second pot. However, you might want to use only soil, instead of filling it with rocks to make it heavier.
By now, you know that growing sunflowers in pots is a definite possibility. Even if your house isn’t tall enough to grow a world-record sunflower inside, you can still enjoy some sunflower seeds without the birds stealing them first.
I hope that you found this article helpful – if so, please share it with someone who can use the information. If you have any questions or advice about growing sunflowers in pots, please leave a comment below.