Dahlias are usually the stars of the garden, pumping out gorgeous, colorful blooms all through late summer and right up until the first frost.
When Your Dahlias Aren’t Blooming
Sometimes, though, these beauties just refuse to flower, and it can be super frustrating. If your dahlias are on strike, it’s usually down to one of these common culprits:
- The wrong spot in the yard
- Soil that’s either too soggy or bone dry
- Nutrient issues (too much or too little fertilizer)
- Tubers that have grown too large
- Pests or diseases
Location, Location, Location
Dahlias are sun-worshippers. They crave a warm, sunny spot to really show off. While they can technically survive in partial shade, you’ll definitely notice fewer flowers. If you want that “wow” factor, make sure they’re getting plenty of direct sunlight.
Watering Woes: Too Wet or Too Dry
Dahlias need loose, well-draining soil. They absolutely hate “wet feet”—standing water is a death sentence. If you’re growing them in pots, make sure there’s great drainage so excess water can escape. If the soil stays too swampy, the tubers can rot, which won’t just kill the flowers, but the whole plant.
On the flip side, don’t let them go thirsty! Dahlias are thirsty plants. During a heatwave, you might even need to water them twice a day to keep them happy and blooming.
Fertilizer Fails
Dahlias are heavy feeders, so they definitely need some extra nutrients. However, it’s a balancing act. If you use a synthetic fertilizer with too much nitrogen, you’ll get a massive, leafy green bush but zero flowers. For the best results, stick to organic options like compost or horn meal mixed into the soil.
Overgrown Tubers
Believe it or not, a tuber can actually get too big for its own good. When tubers become oversized or overcrowded, they start competing with themselves for nutrients, leaving nothing left for flower production. To fix this, it’s a good idea to divide your tubers before planting them in the spring, making sure to give them plenty of elbow room in the garden.
Pests and Diseases
While dahlias are pretty hardy, diseases can occasionally pop up. More often than not, though, the problem is garden pests. Slugs, snails, and voles love dahlias just as much as we do. If they’re munching on the roots, leaves, or emerging buds, your plant won’t have the energy to produce those stunning blooms.
