Except for a few dwarf varieties, most sunflowers have one goal: to reach for the sky. Since most of them bloom and fade within a single season, they have to move fast. However, that genetically programmed “need for speed” can be slowed down if their living conditions aren’t quite right.
From Zero to Sixty in Three Months
Many sunflower varieties are annuals, meaning they only have one season to show off their full glory. To make that happen, they grow at an incredible pace. In fact, it usually takes just about three months from the time you sow the seed until the plant reaches its full height.
If you look at a “classic” sunflower—the kind with the long stalk and one massive bloom on top—you’re looking at a plant that can easily hit 10 feet (3 meters). On average, that breaks down to:
- About 3 feet of growth per month
- Roughly 1 inch of growth every single day
Growth and Size Depend on the Variety
It’s not just about those giant sunflowers you see painting the countryside gold. For home gardeners, there are tons of varieties to choose from, whether you want them as ornamental highlights in the yard or in containers. If you’re looking for something more permanent, perennial sunflowers are mostly hardy and restart their growth from the ground up every year. On the other hand, dwarf sunflowers usually top out between 15 and 60 inches, making them the perfect potted plants for your balcony.
The Best Conditions for Fast Growth
Sunflowers grown in pots tend to be a bit more modest and stay shorter than their genes might suggest. This is simply because their roots have less room to spread out. Aside from pot size, there are three main factors that dictate how tall your sunflowers will get:
- Location
- Nutrients
- Water
To get the best growth, give your sunflowers a spot in full sun with at least five hours of direct sunlight a day. Mix some mature compost into the soil and fertilize the plants up to twice a week during the growing season. Water them every morning, and on those scorching summer days, give them another drink in the afternoon. Just make sure the soil stays moist but not waterlogged—nobody likes soggy feet!
Giving Your Plants a Head Start
Since annual sunflowers aren’t frost-hardy, you can’t sow them outdoors until late April. That’s also around the time you can safely transplant store-bought starts. If you don’t want to wait that long (which can lead to a late blooming season), you can give them a head start by starting your seeds indoors as early as March.
Quick Tip:
Looking for something a little different? Why not try a sunflower that skips the yellow and goes for a deep brick red? The variety Evening Sun (Abendsonne) is a showstopper that produces multiple blooms on a single plant!
