Sunflowers bring us back to our childhood; they are huge, brightly colored with gold, orange and red, tall and… They just look like they’ve come from a world of giants! When we are kids, we don’t know that they are actually inflorescences, but then, does it matter?
They look like oversized daisies that make us feel like gnomes anyway! And you can sow them till quite late in the season, including June. But how can you make sure that they dwarf all other varieties in your garden?
To get really massive flowering sunflowers even if you sow them in June, I have 10 tips for you!
Tip 1 – Choose Giant Varieties
This seems obvious, because not all sunflower varieties are massive. So, pick a giant cultivar or species, and the biggest are:
- ‘Titan’
- ‘Giraffe’ (very tall, as the name suggests, up to 17 feet, or 5,7 meters!)
- ‘Giant Yellow’
- ‘Pike’s Peak’
- ‘Mammoth Grey Stripe’
- ‘Russian Mammoth Sunflower‘
- ‘Mongolian Giant Sunflower’ (with blooms that reach 18 inches, or 45 cm across!)
There are many others, of course, in shades from yellow to almost black, and some are even greenish. But you got the point: check out the height and flower size before you buy the seeds.
Tip 2 – Find a Sunny Spot for Your Sunflowers
As their name suggests, sunflowers like full Sun conditions, otherwise their blossoms will underperform. So, sow them where they can receive at least 6 to 8 hours of bright sunlight every day.
Tip 3 – Always Direct Sow Your Sunflower Sees!
With many veggies and decorative varieties, we sow the seeds in trays and then we transplant the seedlings; forget that with sunflowers!
Sow them directly in your garden, because sunflowers don’t take well at all to transplanting. Here’s how:
- Loosen the soil to a depth of about 4 inches (10 cm).
- Pick some plastic crates, or dish racks.
- Press them into the soil, then remove them.
- You can fertilize if you want, with some compost; but it’s really not necessary with sunflowers.
- Sow the seeds, 1 to 2 inches deep (2,5 to 5.0 cm) and about 10 inch spacing (25 cm), for a thick display, avoiding the grooves left by the crates or dish racks.
- Water.
Tip 4 – Protect the Seeds and Your Young Sunflowers from Hungry Birds
Sunflower seeds are very nutritious and birds love them. Did you think you hid them from our flying friends underground? Forget it: they will find them anyway. So, what were the crates or dish racks for? To protect them.
They will also protect your sunflowers when they are young, and their leaves are still tender and tempting for other animals. Then they get rough and fuzzy, and they are safe.
So, replace the crates where you had pressed them: light and water will get through, birds won’t!
Of course, you need to remove the crates or dish racks once they outgrow them. By this time, they will be safe.
Tip 5 – Mulch Your Sunflower Seedlings
Once the sunflowers have sprouted, you should mulch them, so no weeds grow, and the soil keeps moist and fertile. 2 inches (5.0 cm) of cheap dry leaves or straw, or wood chipping, or bark if you want a great looking bed will suffice.
Tip 6 – Water Sunflower Seedlings Regularly
Sunflowers are moderately drought tolerant, but not when they are young. Dry spells can be disastrous for them and at the very least, they will stunt their growth. So, irrigate your saplings every other day for the first two to three weeks of their life – especially if you sow them in June, when it’s hot!
After that, when they are about 12 inches tall (30 cm), depending on humidity, you can reduce this routine to twice a week for adults.
Tip 7 – Fertilize Your Sunflowers Once They Reach About 12 Inches
By the time your sunflowers reach about 12 inches tall (30 cm), they will need some food, especially if you want them to grow massive and give you huge flowers.
Use a fast-release liquid fertilizer with NPK 5-10-10 every other week, preferably an organic brand, of course!
Tip 8 – Pre-Sow Some Sunflowers for Early Blooms
Sunflowers have a very long sowing season, from February till June… It depends on the climate, of course, but have you seen their seeds? They have a “tough skin” and they will resist frost as well. If you want to be safe, cover them with some mulch (leaves will do) till they germinate.
This way, you will get a much longer flowering season. You haven’t done it this year? Keep it in mind for next year… Or better, look at Tip 10…
Tip 9 – Boost Them When You See the First Flowers
With other plants, you may miss the first flower buds, but not with sunflowers. Well, when they appear, they become really hungry. You can imagine the energy they need to produce such massive blooms.
At this stage, feed them a double dose of a fast-release liquid fertilizer with NPK 5-10-10. Then switch back to the normal routine (Tip 7) till they have stopped blooming.
Tip 10 – Allow Nature to Give You a Hand!
And the last tip will save you a lot of time and money! The only thing you need to make sure of is that little birds don’t eat all the seeds, and your sunflowers will sow themselves and they will start cropping up here and there in your garden next year!
No effort at all, no expense at all, and, as we have seen, sunflower seeds are frost resistant!
To make sure that some seeds drop to the ground, once they are ripe and the blooms are spent, all you need to do is shake those massive flowers. You won’t need all of them, only a few, unless you want to fill your garden with sunflowers…
The only job you’ll have next year will be to thin them out! Or add new varieties to your collections!
A Garden of Giants in 10 Easy Steps
Sunflowers are very reliable, and their blooms, if you follow these ten easy tips, will never disappoint. This way, you can have a garden of giant flowers, and go down memory lane to when you were a kid, and felt like a fairy or a gnome in an enchanted garden…
Written By
Amber Noyes
Amber Noyes was born and raised in a suburban California town, San Mateo. She holds a master’s degree in horticulture from the University of California as well as a BS in Biology from the University of San Francisco. With experience working on an organic farm, water conservation research, farmers’ markets, and plant nursery, she understands what makes plants thrive and how we can better understand the connection between microclimate and plant health. When she’s not on the land, Amber loves informing people of new ideas/things related to gardening, especially organic gardening, houseplants, and growing plants in a small space.