My love of gardening started with sunflowers as they are personal to me. This led me on to a journey of growing the best ones I could and, eventually, selling them! If you’ve just bought a sunflower, there are a few things you need to know.
How you look after them will not only affect their overall health but how much they grow. Here you’ll see some general advice on how to get the best results.
The Basics
The sunflowers I sell can get over 8 feet in height and grow multiple heads. However, I’ve kept some unsold sunflowers in pots that barely got above a couple of feet and grew one, small head. The point being that the conditions significantly affect the outcome.
The best conditions are:
- Fertile, well-draining soil (compost)
- Full all-day sun
- Buried in the ground, not in a pot
- Support from a stake
- Consistent, deep watering
You absolutely don’t need to do all of these things. This is just a guide. For example, a well looked after sunflower in a large pot will still grow well and look lovely. It just won’t be a giant. Here I’ll go into these points in a little more detail.
Choosing the Right Spot
Sunflowers, unsurprisingly, need a lot of sun. They will thrive best in the sunniest spot in your garden. The most south-facing position is usually best for this but double-check for anything that may clock the light, such as fences or trees.
Sunflower stems on extra-tall plants will grow extraordinarily thick but they are still vulnerable to high winds. Sunflowers will generally do best when they are situated a few feet away from a wall or fence that can give them some protection.
You should also combine with staking. Ideally, a 6ft bamboo can is ideal for this. If that’s not practical but give it as much support as you can. Attach the stake to the sunflower with twine, making sure to re-tie this twine as the stem gets thicker.
Consistent Watering
You want the soil of a sunflower to be consistently moist. This doesn’t always mean watering every day. Instead, when you water, you want to do it deeply so that the water can deep down deep into the roots.
If you water too much, the roots can actually rot. The best way to check is that once the first inch of top soil starts to dry, give it another deep watering. Sunflowers are incredibly thirsty, so make sure to stay on top of this.
Ongoing Care
Sunflowers will benefit from regular feeding with any decent balanced fertilizer, they don’t need any specialist type. Don’t give it a tomato feed, as this type of fertilizer is best for any plant that fruits. You will only need to feed it every couple of weeks.
Once a sunflower goes into full bloom, you’ll get to enjoy it for about 2-3 weeks. That’s why I love growing multi-headed varieties as it allows you to enjoy that beautiful bloom for longer as heads open up at different times.
Once the head starts to droop and the petals start to shrivel, that’s when you want to cut it off to further encourage further heads to grow. That’s unless you want to keep the seeds. If so, leave it for about two weeks longer to ensure those seeds have matured.
I’ve never found pests to be too much of a problem with sunflowers but keep a check on them for any issues. Slugs can be picked off. Aphids with a blast of mild soap and water. They can develop a fungal infection, but these can easily be controlled with a spray.
Sunflowers are one of the most resilient annual plants. They will still survive and grow in conditions that are far from ideal. But if you follow my advice here, you can enjoy an epic sunflower that will eventually tower over you.