Grow and care for dahlias throughout the season
Dahlias grow quickly, producing bushy plants and blooming in the first season.
Water regularly and try to keep your foliage dry. Avoid overwatering, as moist soil can lead to rotting tubers. We recommend less frequent, but deep watering.
It is best to let the soil dry out between waterings, as moist soil can easily cause tubers to rot (remember – this is why good soil preparation is so important). Water well about once a week until the dahlias germinate.
When you see top growth, water as needed when the soil has dried out. When the plant starts to grow and the temperature increases with the beginning of summer, you may need to water more often. If you experience regular rain, you may not need to water unless your soil dries out.
When watering, keep the water close to the soil surface and avoid getting wet leaves to prevent disease. Water slowly and deeply to thoroughly soak the soil.
Look for a fertilizer that is high in potassium (K) and phosphorus (P) but low in nitrogen (N). Potassium and phosphorus promote bud growth and flowering. to prevent lush bushes with few blooms. Check your NPK (nitrogen-phosphorus-potassium) levels in your fertilizer before you buy. Expert growers recommend formulas like 5-10-10, 10-20-20 or even 0-0-10. Fertilizing dahlias just a couple of times can make a big difference to the flower crop. Add at planting and no more than once a month before flowering begins.
In very hot, dry areas you may want to mulch to retain moisture, but in most areas we recommend skipping compost so the soil can stay warmer and the foliage can stay dry.