Idaho gardeners know something special about growing dahlias that make their blooms absolutely massive. The cool nights and warm days in Idaho create perfect conditions for these stunning flowers.
With the right tricks and techniques, you can grow dahlias so big they’ll make your neighbors stop and stare in amazement.
1. Pinch Back Early Growth
When your dahlia plants reach about 12 inches tall, snap off the top growing tip with your fingers. Your plant might look smaller at first, but this simple move encourages more stems to grow from the sides.
More stems mean more flowers, and the plant puts extra energy into making each bloom bigger and better. Idaho gardeners swear by this method because it works every single time.
Wait about two weeks after pinching, and you’ll see new shoots sprouting everywhere.
2. Feed With Fish Emulsion Weekly
Fish emulsion might smell a bit funky, but dahlias absolutely love this natural fertilizer. Mix it with water according to the bottle directions and pour it around your plants once every week during the growing season.
The nutrients in fish emulsion help dahlias grow strong roots and produce enormous flowers. Idaho’s soil sometimes lacks certain minerals, so this liquid food fills in those gaps perfectly.
Your blooms will grow noticeably larger within just a few applications.
3. Stake Plants Before They Need It
Giant dahlia blooms get heavy, and without support, the stems can snap right in half. Put sturdy stakes in the ground when you first plant your tubers, even though they seem tiny at the time.
As your dahlias grow taller, tie the main stems loosely to the stakes using soft garden twine. Idaho winds can be pretty strong, especially in the evening hours.
Staking early prevents damage and keeps those massive flowers standing tall and proud all season long.
4. Disbudding For Monster Blooms
Did you know that removing some buds actually makes the remaining flowers grow bigger? When you see three buds forming together on a stem, carefully pinch off the two smaller side buds.
All the plant’s energy then flows into that one remaining bud, creating a truly massive bloom. Idaho dahlia enthusiasts use this trick when they want show-stopping flowers for competitions or special occasions.
The results are honestly incredible, with blooms reaching dinner-plate size or even larger.
5. Deep Watering At Soil Level
Dahlias need plenty of water to produce those gigantic blooms, but how you water matters just as much as how much. Always water directly at the soil level instead of spraying from above.
Overhead watering can cause disease problems and doesn’t reach the deep roots where plants need moisture most. Idaho summers can get quite hot, so water deeply two or three times per week.
Soil should stay consistently moist but never soggy or waterlogged for best results.
6. Mulch Heavily Around Plants
Spread a thick blanket of mulch around your dahlia plants, about three to four inches deep. Mulch keeps the soil cool during Idaho’s warm afternoons and holds moisture in the ground where roots can access it.
Wood chips, straw, or shredded leaves all work wonderfully for this purpose. The cooler root zone helps plants focus energy on bloom production instead of stress management.
Plus, mulch stops weeds from stealing nutrients that should go to your flowers instead.
7. Choose The Right Varieties
Not all dahlias grow equally large blooms, so picking the right variety from the start makes a huge difference. Look for types labeled as dinner-plate dahlias or giant-flowered varieties at your local nursery.
Popular choices in Idaho include Cafe au Lait, Kelvin Floodlight, and Penhill Dark Monarch. Some varieties naturally produce blooms measuring ten inches across or even bigger.
Starting with genetics designed for size gives you a serious advantage before you even plant anything.
8. Harvest Blooms Regularly
Cutting flowers might seem like you’re reducing your display, but it actually encourages plants to make even more blooms. When you remove flowers regularly, the plant thinks it needs to produce more to make seeds.
Cut stems in the early morning when they’re full of water, taking them back to a leaf joint. Idaho gardeners fill their homes with beautiful bouquets while their outdoor plants keep pumping out massive new flowers.
The more you cut, the more your dahlias will bloom throughout the entire season.