If you’re like me, then you love growing sunflowers in your cutting garden. They add height and interest to any bouquet or arrangement. But, if you want your blooms to be the best size for the vase, then it’s important to give them the right amount of spacing, which is different than standard guidelines.
If you look at the back of any sunflower seed packet, you’ll see that the recommended spacing is 12-18 inches. If you’re growing sunflowers to enjoy in your landscape, that spacing is great.
However, if you’re planning to cut your sunflowers for a bouquet, you’ll have to learn to space them differently.
Sunflowers grown for cut flowers should be spaced 4-9 inches apart. The single stem of a cutting sunflower will grow tall and straight while staying thin enough to be easy to use with other flowers in arrangements. Wider spacing will allow the sunflower to get too big to be practical for flower arrangements.
Let’s dig into the details of each tip so you can have the best results when cutting sunflowers for arrangements.
1. Keep single stem sunflowers close
Single stem sunflowers produce one central stem lined with leaves but no big side stems or secondary blooms. They are the perfect type of sunflower pack into your cutting garden with their upright growth.
Aim for 4-9 inches between each sunflower seed. If you want to be very precise, you can measure and mark each spacing. I lay out my irrigation tape with holes every six or nine inches (depending on the tape) and plant a seed at every emitter spacing.
It makes it easy to space out the seeds, and it ensures that every plant will get water without having to hand water. Win-win!
2. Give branching sunflowers more space
On the other hand, branching sunflowers have multiple side stems in addition to the main stem. Each side stem produces a flower, so these sunflowers need much more room. 12-24 inches is ideal, which will allow all the branches plenty of room to develop and grow straight.
It’s worth growing a branching sunflower or two if you have the room because they’re great at attracting pollinators, and you’ll get a longer period of blooms, about 2-3 weeks.
3. Dwarf sunflowers…it depends
Dwarf sunflowers grow on much shorter stems, as the name implies, making them perfect for small spaces or containers.
These little beauties grow only 12-18 inches tall, making them a perfect candidate for container gardens as well as regular gardens. Whether you grow them in pots or in the ground, space them 6-12 inches apart.
There are single stem and branching dwarf varieties, so the spacing will depend on the type you’re growing, just as with the standard sunflower types.
Use succession sowing to keep your space filled
Single stem sunflowers are grown as “one and done” flowers that produce one flower for harvest. After cutting, another sunflower needs to be planted for the next round of blooms.
The best way to keep a continual supply of sunflowers is to sow new seeds every two weeks. This is called succession planting, and it ensures that you’ll always have blooms, even if some get damaged or don’t perform well.
To do this, simply make a new planting in the empty spaces left behind by harvested sunflowers. You can alternate flower beds if those open spaces are too shady due to neighboring plants, though this takes more planning and space than most home gardeners have.
I would love to have a few rows in my garden dedicated solely to sunflowers, but in my small yard, I have to make do with popping a new sunflower seedling in wherever there is room. It’s a little messy, but it works to keep the sunflowers popping!
Even branching sunflowers can be succession planted, though you’ll want to give them a little more time between sowings to accommodate their long blooming period.
What happens if you plant your sunflowers too close together?
Sunflowers that are planted very close together will still grow and bloom just fine, as long as they are getting full sun exposure. The result of crowded sunflowers will be longer stems and smaller flower heads.
This can be an advantage if you’re cutting sunflowers for arrangements because the smaller flower heads will be easier to work with. The longer stems will give you more to play with when designing your arrangement.
Flower farmer Lisa Mason Ziegler sometimes intentionally plants her single stem sunflowers just four inches apart to get diminutive sunflower heads resembling daisies. These smaller blooms are perfect for bouquets.
The downside is that these sunflowers could be more susceptible to wind and heavy rain damage because the stems may be weaker than usual.
If you want to attempt ultra-close spacing, be sure to stick to single stem varieties for a higher chance of success.
How many sunflowers can you plant in a square foot garden?
Square foot gardening is a very popular method for spacing plants in the garden, but it does run contrary to the close spacing recommended for sunflowers grown specifically for cutting.
Only one sunflower would be prescribed per square foot, resulting in too-large sunflowers and a waste of space in the garden. A better option would be to bend the rules of square foot gardening and pop in two seeds per square foot.
I would recommend sticking to traditional row planting for your sunflowers to get the most production out of your space and use the square foot gardening method for the rest of your garden.
Square foot spacing will work much better if you’re growing branching sunflowers to enjoy right in the garden. One square foot would be the minimum space needed to make sure each branching sunflower has room to grow without crowding neighboring plants.
You can always stick to smaller branching varieties such as Little Becka sunflower, which branches heavily but tops out at three feet tall.
Sunflowers aren’t the only flower that needs special spacing considerations. Check out this post cut flower spacing for more tips: How To Space Annuals For Cut Flower Production (With Chart)
If you feel confident in arranging your sunflowers in the garden but are still stumped on which varieties to grow, I’ve got you covered with a list of recommended varieties: What Sunflower Varieties Are Best For Cutting?