How to Grow Sunflowers From 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 one of the best flowers to grow at home, as they are simple to grow from seed and wonderful flowers for attracting beneficial pollinators. Later in the season, the dried flower heads can be food sources for birds in your garden too! Continue reading to see how to grow sunflowers in your garden.
Quick Sunflower Growing Tips
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.
Sunflowers like full sun, and seeds can be started as soon as the weather warms and no chance of frost is present. Find a sunny spot in your garden!
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.
One of my first experiences learning how to grow sunflowers. These were all short varieties because I didn’t want to shade out the other crops growing in the raised bed.
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 sometimes start my sunflower seeds in pots or seed cells. Gardeners often say that sunflowers don’t handle transplanting well due to having a large taproot, but I have grown a majority of the sunflowers that you see in my garden by transplanting. It works!
I personally think both direct sowing and transplanting are valid options for sunflowers. If pests aren’t a big issue, I’d much rather direct sow sunflower seeds generously and thin later.
Direct Sowing Sunflower Seeds in the Garden
Find your planting location. Full sun is best! Sunflowers can actually handle poorer quality soils. Feel free to select a variety of blank spots to try out! Sunflowers prefer warmer temperatures, so waiting to sow until all frost has passed (or even until early Summer) 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.
Sowing Sunflowers in Seedlings Cells or Pots
In general, the instructions are the same as above, but you would fill your seed cells/trays with soil and poke a hole about an inch deep. Typically, I’ll drop 1-3 seeds in each hole just to guarantee some germinate. Afterwards, you can thin out the weaker seedlings.
There are some extra steps involved if you are starting your seeds in cells or pots for transplanting later. Simply follow instructions as outlined in The Basics of Growing From Seed and then you will transplant your sunflowers into the garden.
A homegrown assortment of sunflowers in a mason jar. It’s so fun to watch them grow from a seed into a huge plant!
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. It’s worth it to try various areas of your garden and see how the sunflowers perform! 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 Your Own Sunflower Seeds
Now that you know how to grow sunflowers, let’s chat about saving your own seeds so you can grow sunflowers for years to come! In general, 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. At this point, 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.
Here’s an example of a sunflower in my garden that is drying out. The heads will lose their petals and start to yellow and turn brown. See my notes for how to save your own sunflower seeds.
Notes on Saving Sunflower Seeds
While this is a topic that deserves an article all its own, I haven’t written anything in-depth on saving seeds…..yet. 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!
Finally, sunflowers can self seed in your garden. Oftentimes, 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.
How to Grow the Best Sunflower Varieties
After years of growing sunflowers, I’ve learned some tips for how to select good varieties of sunflowers to grow. First, you want to look for “multi-branching” types. Multi-branching sunflowers will give you more blooms per main stem as opposed to one flower at the top of the main stem. Nowadays, I try to only grow multi-branching sunflowers.
Second, think about your sunflower goals. Are you growing sunflowers as a cut flower? Are you growing sunflowers for pollinators? Or maybe you’re interested in trying to eat your sunflowers? Each of these reasons will lead you to purchase a different sunflower. For instance, avoid pollen-less varieties of sunflowers if you are growing them for bees. Multi-branching types are better for cut flowers. And lastly, some sunflowers form better heads for eating (I’ve never tried it, but I’ve seen them online) so keep an eye out for that on the seed packet.
Below I’ve listed some of my favorite sunflowers to grow for beauty, pollinators, and cut flowers:
‘Evening Sun’ sunflower
‘Evening Colors Blend’ sunflowers
‘Teddy Bear’ -a charming dwarf sunflower variety
‘Hella Sonnenblume’– a shorter, multi-branching variety
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