How To Grow The Best Dahlia Flowers: Pinching, Debudding, Fertilizing & Tips

Whether you’re growing a cut flower garden, or you simply want the most beautiful display in your garden, Dahlias are famous for their blooms. The great news is that cutting Dahlia flowers will actually encourage more flowering!

If you want above and beyond flowers - especially those humungous Dinner Plate Dahlia blooms up to 10 inches wide, we have tips on disbudding for success.

Or, if you’re hoping to have a productive season to get as many stems as you can, we can help you learn how to pinch your flowers for plentiful blooms. 

As you grow and experiment, you will find the techniques that work best for you!

Helpful Tips For Dahlia Flowers:

• Preparation Is Essential
• Before You Start: Buds 101
• Disbudding For Dinner Plate Dahlias
• Pinching For Plentiful Flowers
• Fertilizing Do's and Don'ts For Dahlia Flowers
• Cut Flower Tips For Dahlias

First and foremost, planting Dahlias in well-prepared soil where they’ll receive the right amount of light, and tending to your plants as they grow, is the first step toward amazing blooms. If you haven’t yet - be sure to read our guide: How To Grow Dahlias.

Here are three important things to remember about Dahlia buds:

• Dahlias typically set one large bud at the tip of a growing stem, called the terminal bud
• They also set a pair of smaller buds to the left and right of that, called lateral buds.
• It’s most effective to pinch or disbud when buds are small.

What is it? Disbudding is removing the lateral buds (side buds) from a Dahlia to focus the plant's energy into one large flower.

Why do it? Typically this is used for Dinner Plate Dahlias or other varieties where you want to reach the maximum size for your flower. Disbudding is removing all buds except the terminal bud, effectively throwing all of the plant's energy into the one remaining terminal bud.

Pros & Cons: While disbudding can result in one giant flower, there is a potential downside of missing out on the abundance of blooms you could get from the plant. 

Tip: If growing for maximum flower size, be sure to support your Dahlia stems with stakes to hold up the heavy flowers!

What is it? Pinching is a technique of pinching or trimming the central terminal bud of a Dahlia.

Why do it? When the larger central bud is removed, the plant will send more energy into the lateral buds (side buds) This will result in more abundant flowers, perfect for cutting.

Pros & Cons: The flowers may not be massive, but there will be many flowers on the plant. The more the merrier!

Tip: Remember, cutting flowers or dead-heading spent blooms will also encourage more flowering.

Do:

• Look for a fertilizer that is high in potassium (K) and phosphorus (P) but low in nitrogen (N). Potassium and Phosporous encourage bud growth and flowering.  to prevent leafy bushes with few blooms.
• Check your NPK (Nitrogen-Phosporous-Potassium) levels in your fertilizer before you purchase. Expert growers recommend a formulas such as 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 yield. Add when planting, and once a month at most before flowering begins. 

Don't: 

• Don't use too much nitrogen (N). Nitrogen encourages leafy green growth, not flower buds.  
• Don't use too much fertilizer, or apply more often than needed. Too much fertilizer will cause yellow leaves and drooping plants.

• Unlike some other flowers, once Dahlias are cut, they don’t keep opening and expanding in the vase.
• Cutting a Dahlia at peak bloom is the best for looks and a long vase life. 
• Look for firm & lush petals - if petals are papery or dry, the flower may have a shorter vase life.
• Cut flowers or deadhead regularly. This will allow the plant to divert energy away from the spent flower, and put more energy into growing blooms. 
• Cut dahlias typically last about 5-7 days. To keep cut flowers lasting longer, give them fresh water often.

Q&A: Troubleshooting For Dahlia Plants

Discovering Dahlia Flower Forms: Find Your Favorite Flower

How To Store & Dig Dahlias For Winter