How to Grow Sunflowers in Containers - Backyard Boss
We are reader supported. External links may earn us a commission.

How to Grow Sunflowers in Containers

Everyone wants a unique garden, which is why people often turn to beautiful blooms that are difficult to grow or that may have invasive tendencies. Never fear; there are some quite versatile and easy-to-obtain plants that can add zing to your garden! Sunflowers are a popular choice among expert and amateur gardeners alike. These gorgeous herbs are more than just a wonderful decoration and they bloom all summer!

Sunflowers attract pollinators, yield yellow dye, and produce seeds you can use to make oil and food. But what happens when you don’t have a backyard to grow these beauties? Don’t worry, if you don’t have enough ground space to grow them, here’s a step-by-step tutorial on how to grow sunflowers in containers!

What to Consider When Growing Sunflowers in Containers

mini sunflower growing in pot
Image credits: daryl_mitchell via Creative Commons

While it is possible to grow common sunflowers in containers, in theory, it is probably not the best idea, unless you have at least a 10-gallon container, because they have a taproot that can grow to 10 feet!

If you lack the space or the container, it’s better to grow a mid-size variety, such as Taiyo, or dwarf varieties, such as the Sungold Dwarf or Lemon Queen. These won’t take up too much space and are also quite easy to maintain.

However, it is important to remember a few things when picking the right container for your sunflowers:

  • Lightweight planters made of terracotta or plastic that are 6 to 8 inches deep and 10 inches wide are ideal.
  • Heavy pots are not recommended because it would be difficult for you to move them around.
  • Grow bags are ideal because they’re lightweight, reusable, and retain moisture.

What You Need to Follow This Tutorial

Terracotta pot with organic soil inside and some outside with green leaf on the old cement floor
Image credits: sirampuch eamumpai via Shutterstock

To plant your sunflowers in containers, you will need the following materials and tools:

  • A proper container
  • Potting soil
  • Compost
  • Sunflower seeds

Step-by-Step Tutorial to Growing Sunflowers in Containers

Step 1: Choosing the Sunflower Variety and the Container

a) Buy Sunflower Seeds

sunflower seeds
Image credits: nonnatthapat via Pixabay

You can easily find sunflower seeds in most gardening stores and nurseries. However, if you are looking for a rarer type, look online. For best results, look for dwarf varieties, because larger ones grow better in the ground or in very large containers.

Pro tip: If you know someone with fully grown sunflowers in their garden, take some of their seeds, and store them in an airtight container. You can store them in the fridge until you’re ready to use them; however, plant them as quickly as possible as older seeds will not be as easy to grow.

b) Choose the Correct Container Size

Stack of galvanized gardening pails and containers
Image credits: congerdesign via Pixabay

Your container size will be based on the height and the number of sunflowers you want to plant. Typically, if you are planting dwarf sunflowers, use a 12 to 16-inch pot for two or three sunflower seeds. As a rule of thumb, use one seed for each 6-inch pot.

Pro tip: If you are reusing a container, make sure you sterilize it well and that it has enough drainage holes.

c) Pick the Right Potting Soil and Compost

potting soil
Image credits: Neslihan Gunaydin via Unsplash

Look for potting soil and potting compost that will allow your sunflowers to thrive. Sunflowers prefer soil that is slightly acidic (with a pH between 5.5 and 6.8).

Pro tip: If you are using topsoil of high quality, don’t add drainage material because this may actually hinder the movement of water and stop proper drainage.

Step 2: Planting Your Sunflower

a) Put the Seeds Into the Soil

planting a seed
Image credits: Markus Spiske via Unsplash

Push seeds gently into the soil at about a 1-inch depth. If you want to plant more than one seed, allow about 5 inches of space between each seed. Remember the one seed per 6-inch pot rule for healthy growth.

Pro tip: Add a thin layer of compost on the top after you’ve put the seeds in for optimal results.

b) Water Consistently

Image credits: A Magical Mess via Giphy

Sunflowers require at least 2 gallons of water each week while the seeds are germinating. Ensure that the soil is moist but well-drained. The best way to find out if your plant needs water is to stick your finger in the soil to test moisture. If the soil is moist, your plant doesn’t need a drink, but if it’s dry and crumbly, it needs water.

Pro tip: If you see that your sunflowers have thin or weak stems, this means that they didn’t receive enough water.

c) Wait for the Seeds to Germinate

seed sprouting
Image credits: imso gabriel via Unsplash

It will take about 10 days before your seeds become seedlings. Continue watering the seeds each day.

Pro tip: Birds are quite drawn to sunflower seeds, so you may want to cover the seedlings with baskets or netting to provide protection.

Step 3: Taking Care of Your Sunflower

a) Add Fertilizer

Chemical fertilizers isolated on white background.
Image credits: Nuttapong via Shutterstock

Sunflowers don’t particularly need additional feed for their growth. However, fertilizer can make the colors on the petals much bolder. You should begin by using nitrogen liquid fertilizer, then change it to a phosphorus one once the buds start to bloom.

b) Keep in Direct Sunlight

sunflower seedlings on window sill
Image credits: Andy Hay via Creative Commons

While the seedlings are growing, they will require a lot of direct sunlight. Make sure that they get at the very least six to eight hours of sunlight a day.

c) Water Regularly

warering sunflower
Image credits: Menage a Moi via Creative Commons

You will need to water sunflowers quite a bit. You should check the soil every day — it should be moist. If you keep your sunflowers outside, rainwater will compensate for some of the watering.

d) Put a Stake in if Needed

stakes for vines and flowers
Image credits: coconut wireless via Creative Commons

While most dwarf varieties will not become tall enough to need support, any variety that reaches over 3 feet should be attached to a stake to keep the flower head from flopping or drooping.

e) Harvest the Seeds

sunflower seeds separated from flower
Image credits: Devi Puspita Amartha Yahya via Unsplash

If your sunflower variety gives you a yield of edible seeds, then you should let the flower die on the stem. You will see them become dry and ripe and ready for harvest. However, if your sunflowers are outdoors, you may have to cover them with netting to protect them from birds.

Pro tip: For consumption, you can keep the sunflower seeds in an airtight container for up to four months at room temperature. If you plan on using them to grow more sunflowers, it’s best not to store them for too long.

In Summary

Sunflowers are a fantastic and beautiful addition to any garden. However, many people don’t the space to grow mammoth — or even common — sunflowers. This is why they typically opt for the dwarf varieties, which are very well suited for container cultivation. And while they may require some extra watering, in the end, it is absolutely worth it.

Hopefully, this tutorial inspired you to grow sunflowers in containers. As always, post your experiences and thoughts in the comment section down below, and don’t forget to share the article if you enjoyed it.

Happy Gardening!