How to Grow Sunflowers ~Sow, Grow, and Save Seed
I don’t think you can look at a sunflower and not smile. If you aren’t sure, I challenge you to grow some and see! Sunflowers are simple to grow from seed and wonderful flowers for attracting beneficial pollinators, like bees. Later in the season, the dried heads can be food sources for birds in your garden too! Continue reading to see how to grow sunflowers in your garden.
The Basics ~ How to Grow Sunflowers
I strongly recommend starting sunflowers from seed. In fact, I don’t know if I’ve ever seen sunflowers sold at nurseries as plants (besides some special bush varieties). Sunflowers are one of the easiest seeds to sprout, and for just a few dollars you can get a whole packet of seeds. If you’d like a list of places I purchase seeds, see here→ Where I Buy Seeds
Sunflowers like full sun, and seeds can be started as soon as the weather warms and no chance of frost is present.
Take note of the mature height of the sunflower (it’s usually listed on the seed packet). There are so many different kinds of sunflowers. For instance, some only grow 24″ tall while others can grow 7ft or more! Knowing how tall your sunflowers will grow allows you to plan your garden space more efficiently.
Sunflowers will often re-seed of self-sow in your garden. Essentially, once you start growing sunflowers, the seeds can become scattered by birds or the wind and end up sprouting up in your garden the next season. It’s really worth leaving the sunflower heads to dry in the garden or letting them grow wild.
Choosing to Direct Sow or Transplant Sunflowers
Sunflower seeds can be directly sown into the soil or started in pots to be transplanted out in the garden later. Surprisingly, I go against most gardening advice that tells you to direct sow because of my garden situation. Deciding how to grow sunflowers should be based on your particular garden space and Direct Sowing Versus Transplanting covers some of the factors I consider when making this choice. It is generally understood that direct sowing is better for the taproot of sunflowers and is less work without the fuss of transplanting, but for my garden I am often unable to direct sow sunflowers.
My garden has a major issue with birds and pests like roly polies. If you want to know what I’m talking about, you can check out my roly poly article here. No matter how many times I try to direct sow sunflowers, my seedlings get eaten by birds or bugs. Can you blame them? Sunflower sprouts are like fresh salad to them!
To avoid this pest issue and still grow gorgeous sunflowers, I use large peat pellets or pots to start my seedlings and then transplant them into the garden. Gardeners often say that sunflowers don’t handle transplanting well due to having a large taproot, but I have grown all my sunflowers that you see in my garden by transplanting. It works!
Planting Your Sunflower Seeds in the Garden
Find your planting location. Full sun is best!
Dig a small channel in the soil with a depth listed on the seed packet (typically it is 1″). Lay your sunflower seeds in the channel and cover with dirt. Leave about 6″ between seeds or follow what the seed packet says. Alternatively, sow seeds closely together and thin them out later to ensure you’ve got good germination and spacing.
If you aren’t planting your seeds in rows or lines, you can poke holes in the soil wherever you’d like and plant your seeds.
Cover with dirt and water well.
NOTE: if starting your seeds in pellets or pots, simply follow instructions as outlined in The Basics of Growing From Seed and then you will transplant your sunflowers into the garden.
Soil Requirements & Watering for Growing Sunflowers
While they do like well-draining, loamy soil, sunflowers can tolerate more dry and clay conditions than other flowers. Read How to Amend Your Garden Organically for my process on prepping my garden beds each season. I typically add some compost or organic potting mix to help amend the soil before planting.
While waiting for seeds to germinate, keep the soil evenly moist. You’ll need to water more frequently while the sunflowers are young with smaller root systems. However, once established, your sunflowers won’t need lots of water. You can typically water deeply once or twice a week (depending on how hot it is).
How to Save Sunflower Seeds
Now that you know how to grow sunflowers, let’s chat about saving seeds so you can grow sunflowers for years to come!
I tend to cut half my sunflowers for arrangements and leave half to go to seed. If you would like to collect seeds for saving and planting, you will have to let the sunflowers stay on the plants until the heads droop and turn brown on the back. This means the seeds are mature and ready to harvest.
If you have problems with squirrels or birds trying to eat the seeds, you can cover the heads with a mesh or fabric to protect them. Alternatively, you can cut the sunflower heads a little early and lay them somewhere safe to dry for harvesting.
When it is time to harvest the seeds, simply take a gloved hand (I say “gloved” because there are some spiky bits in the dried head sometimes), and gently brush your fingers over the head to reveal and loosen the seeds. Always store seeds away from any moisture and keep in a cool, dark place.
Sunflowers will self seed in your garden. Often those that self seed are stronger, more acclimated, and will be left alone by pests. If you’d rather sit back and watch the magic happen, just leave your sunflowers to dry and drop seeds.
A note on seed saving: this is a topic that deserves an article all its own. I haven’t written anything in-depth on saving seeds yet, but just be aware that seeds saved from a hybrid variety will not grow true to the parent plant—-meaning the saved seed won’t make an identical flower the following year. In fact, saved seeds from hybrid varieties could possibly be sterile and not grow at all. Regardless, sometimes it’s fun to see what you get!