Introduction
There is nothing quite like the excitement of seeing the first dahlia buds begin to swell in mid-summer. These plants are the undisputed stars of the late-season garden, offering a variety of colors and shapes that few other flowers can match. At Longfield Gardens, we believe every gardener should experience the joy of our dahlia collection.
While dahlias are naturally generous plants, they often have more potential than they show at first glance. If you want to transform a few stems into a lush, flower-filled hedge, you simply need to use a few proven techniques. This guide is for any gardener who wants to maximize their harvest and see more flowers on every plant.
By focusing on smart maintenance like pinching, deadheading, and proper feeding, you can significantly increase the number of blooms your plants produce. We will show you how to work with the plant’s natural growth habits to keep the flowers coming until the first frost. With a few simple shifts in your routine, you can enjoy a spectacular display all season long.
The Most Important Step: Pinching Your Dahlias
If you want to know how to make dahlias bloom more, the single most effective technique is pinching dahlias. While it might feel a little strange to cut a healthy young plant, this is the "magic trick" that professional flower farmers use to create bushy, productive plants.
What is Pinching?
Pinching, sometimes called "topping," involves removing the top few inches of the main stem when the plant is young. Dahlias have a natural tendency to grow one tall, dominant center stalk. If left alone, the plant puts most of its energy into this one stem, resulting in a tall, spindly plant with fewer flowers.
When you remove that center point, the plant redirects its energy. It sends a signal to the "nodes" (the spots where leaves meet the stem) to grow new branches. Instead of one main stem, you suddenly have four, six, or even eight lateral branches. More branches mean more locations for flower buds to form.
When and How to Pinch
The best time to pinch your dahlias is when they are between 8 and 12 inches tall and have at least four sets of leaves. Look for the very top of the center sprout, where the newest leaves are forming.
- Use a clean pair of garden snips or your thumb and forefinger.
- Locate the main center stem.
- Cut or "pinch" out the top 2 to 3 inches of that center stem, just above the highest set of leaves.
- Be careful not to damage the leaves or the small buds tucked into the leaf joints below your cut.
Within a week or two, you will see new stems emerging from the leaf axils. This creates a sturdier, more balanced plant that is less likely to fall over and far more likely to produce a high volume of blooms.
Key Takeaway: Pinching your dahlias when they are 12 inches tall forces the plant to branch out. This simple step can double or even triple the number of flowers you get from a single tuber.
Cutting Flowers to Encourage More Growth
It sounds counterintuitive, but the more flowers you cut from a dahlia plant, the more flowers the plant will produce. This is because the plant’s primary goal is to create seeds. When a flower stays on the plant and begins to fade, the plant starts shifting its energy away from making new buds and toward developing seeds inside that fading flower.
Harvesting for Bouquets
Dahlias are among the best cut flowers in the world. To get the most out of your plants, make a habit of cutting dahlias for long stems every few days. When you harvest, don't just snip the flower head. Cut a long stem, ideally cutting back to just above a set of leaves or a new side bud.
This deep cut encourages the plant to grow another long, strong stem to replace the one you took. If you only take short stems, the plant becomes crowded with short, "twiggy" growth that doesn't produce high-quality flowers.
The Best Time to Cut
For the longest vase life and the best plant health, cut your dahlias in the cool of the morning or evening. Unlike roses or lilies, dahlias will not open much further once they are cut. Wait until the flower is nearly fully open before you harvest it. Check the back of the flower head; the petals should be firm and fresh, not papery or brown.
Master the Art of Deadheading
If you don't cut every flower for a bouquet, you must practice regular deadheading. Deadheading is the process of removing spent or faded flowers before they can turn into seed pods.
Identifying Spent Flowers vs. New Buds
One of the biggest challenges for new dahlia growers is telling the difference between a new bud and a spent flower head. They can look similar at a quick glance, but there are two easy ways to tell them apart:
- Shape: New buds are usually round and firm, like a marble. Spent flower heads tend to be more pointed or cone-shaped.
- Feel: If you gently squeeze a new bud, it feels solid. A spent flower head often feels soft or squishy because the petals inside are starting to decompose.
How to Deadhead Correctly
When you see a flower that is past its prime, follow the stem down to the next "intersection" where you see new buds or leaves. Make your cut just above that point. Removing the entire stem of the dead flower keeps the plant looking tidy and ensures the energy goes directly into the developing buds nearby.
What to do next:
- Walk through your garden every 2–3 days with a pair of snips.
- Check the back of every flower for wilting or browning petals.
- Remove any faded flowers by cutting back to the next set of leaves.
- Check for any "blind" stems (stems with no buds) and trim them back to encourage new growth.
Fueling Your Dahlias: Fertilizing for Flowers
To produce dozens of large, intricate blooms, dahlias need the right nutrients. However, more fertilizer isn't always better. The type of fertilizer you choose matters just as much as how often you apply it.
Understanding the Numbers
All fertilizers have three numbers on the label, representing Nitrogen (N), Phosphorus (P), and Potassium (K).
- Nitrogen promotes green, leafy growth.
- Phosphorus supports root development and flower production.
- Potassium improves overall plant health and vigor.
If you give your dahlias too much nitrogen, you will end up with massive, beautiful green bushes but very few flowers. This is a common reason why dahlias sometimes fail to bloom.
A Simple Feeding Schedule
Start with a balanced soil. We recommend mixing compost or well-rotted manure into your garden bed before planting. This provides a slow-release foundation of nutrients.
Once the plants are about a foot tall and have been pinched, you can begin a regular feeding routine. Look for a fertilizer that is lower in nitrogen and higher in phosphorus and potassium. A formula like 5-10-10 or 10-20-20 is often ideal for dahlias, and 8 Tips for Growing Better Dahlias covers the rest of the basics.
Apply fertilizer every 3 to 4 weeks throughout the blooming season. Always follow the instructions on the product label to avoid over-fertilizing, which can stress the plants. Stop fertilizing by early September; this allows the plant to start winding down and preparing its tubers for winter storage.
The Foundation: Sunlight and Space
Even the best pinching and fertilizing won't work if the plants don't have enough energy from the sun. Dahlias are sun-worshippers. To maximize blooms, they need a minimum of 6 to 8 hours of direct sunlight every day, and How Far Apart Should Dahlias Be Planted? can help you plan the right spacing.
Sunlight and Bloom Count
If dahlias are planted in a spot that is too shady, they will grow tall and "leggy" as they stretch toward the light. The stems will be weak, and the plant will produce far fewer buds. If you notice your dahlias aren't blooming well, check if nearby trees or shrubs have grown enough to cast a shadow over your dahlia bed.
Proper Spacing for Airflow
It is tempting to plant dahlias close together to create a dense wall of color. However, crowded plants compete for light and nutrients. They also have poor airflow, which can lead to fungal issues like powdery mildew. A sick plant will always produce fewer flowers than a healthy one.
Give your plants enough room to breathe:
- Border varieties: Space about 15 inches apart.
- Standard varieties: Space about 18 to 24 inches apart.
- Large Dinnerplate varieties: Space at least 2 or 3 feet apart.
Proper spacing ensures that every leaf gets sunlight, which provides the energy needed to fuel those spectacular blooms.
Watering for Consistent Production
Dahlias have a high water content, and their large leaves lose moisture quickly on hot days. If the soil stays too dry, the plant will go into survival mode. It will drop its lower leaves and stop producing new flower buds to conserve energy.
Deep Watering vs. Frequent Sprinkling
The goal is to keep the soil consistently moist but not soggy. Deep watering once or twice a week is much better than a light sprinkle every day. Deep watering encourages the roots to grow further down into the soil, making the plant more resilient during heat waves.
Using a soaker hose or drip irrigation is the best way to water dahlias. This delivers water directly to the root zone and keeps the foliage dry. If you must water by hand, try to water at the base of the plant. Wet leaves are more prone to diseases, which can interrupt the blooming cycle.
Mulching to Retain Moisture
A 2-to-3-inch layer of mulch around the base of your dahlias can do wonders for bloom production. Mulch keeps the soil cool and prevents moisture from evaporating. This creates a stable environment for the roots, allowing the plant to focus all its energy on flower production rather than struggling with temperature swings.
Key Takeaway: Consistent moisture is the fuel that keeps dahlia blooms coming. Use mulch to keep roots cool and water deeply to ensure the plant never feels the stress of a drought.
Managing Summer Heat Stress
Dahlias love the sun, but they sometimes struggle when temperatures stay consistently above 90°F. In the peak of a hot summer, you might notice that your dahlias stop producing new flowers or that the flowers they do produce are smaller and less vibrant.
This is a natural response to heat stress. The plant is simply taking a "nap" until the weather cools down. During these heat waves, don't try to force more blooms with extra fertilizer. Instead, focus on keeping the plants well-watered. Once the night temperatures begin to drop in late August and early September, the plants will naturally "wake up" and begin a second, often more spectacular, flush of blooms.
Disbudding: Quality over Quantity
While this guide focuses on how to make dahlias bloom more, some gardeners prefer to make them bloom bigger. This is especially true for "Dinnerplate" varieties. If you want those massive, 10-inch blossoms, you may want to try a technique called disbudding.
Dahlias typically grow buds in groups of three. There is one central "terminal" bud and two smaller "lateral" buds on either side.
- To get more flowers: Leave all three buds to bloom.
- To get larger flowers: Use your fingers to carefully snap off the two side buds, leaving only the center one.
By removing the side buds, you are telling the plant to put all of the energy for that stem into one single, giant flower. This won't give you more blooms, but it will give you the largest blooms possible for that specific variety. While Dinnerplate dahlias are breathtaking, they spend a lot of energy making those giant flowers, so they generally produce fewer total blooms than the smaller-flowered types, like ball dahlias.
Supporting Your Plants to Save Stems
It is heartbreaking to find a dahlia plant laden with buds that has snapped in a summer storm. Every broken stem is a lost opportunity for flowers. To ensure you get every possible bloom, you must provide support for your plants.
Staking and Caging
For standard and tall dahlias, support is not optional. As the plants grow and produce heavy flowers, they become top-heavy.
- Individual Stakes: Drive a sturdy wood or metal stake into the ground at planting time. As the plant grows, tie the main stem to the stake every 12 inches using soft garden twine.
- Tomato Cages: For many gardeners, a heavy-duty tomato cage is the easiest way to support a dahlia. It keeps the side branches from flopping over, ensuring that every bud has a chance to open.
Providing support keeps the plant upright and healthy, which is essential for a long, productive blooming season, and How to Stake Dahlia Plants for Strong and Healthy Blooms has a full walkthrough.
Choosing the Right Varieties
While care and maintenance play a huge role, some dahlia varieties are simply more "floriferous" (flower-producing) than others. At Longfield Gardens, we offer a wide range of dahlias, and some are specifically known for their high bloom count.
If your primary goal is a high volume of flowers for cutting, look for:
- Ball dahlias: These produce smaller, tightly petaled flowers but in huge quantities.
- Dahlia Forms for Garden and Vase: This guide breaks down the major flower shapes, including ball, pompon, and other distinctive forms.
- Single dahlias: These open-faced flowers are very attractive to pollinators and tend to produce a high volume of buds.
While dinnerplate dahlias are breathtaking, they spend a lot of energy making those giant flowers, so they generally produce fewer total blooms than the smaller-flowered types.
Conclusion
Making your dahlias bloom more is a rewarding process that combines a little bit of science with a regular garden routine. By starting with the "pinch" to create a bushy plant and following up with consistent deadheading and deep watering, you can turn a single tuber into a floral powerhouse. Remember that dahlias are one of the few plants that actually reward you for being generous—the more bouquets you cut and share, the more the plant will give back to you.
"The secret to a flower-filled garden isn't a single miracle product; it's the consistent, small actions like pinching and deadheading that encourage the plant's natural urge to bloom."
We are here to help you succeed in your gardening journey. Whether you are planting your first dahlia or looking to expand your collection, focusing on these simple rules will ensure a season full of color and beauty.
Your Next Steps:
- Check your young dahlias this week to see if they are tall enough for their first pinch.
- Pick out a low-nitrogen fertilizer to have on hand for mid-summer feeding.
- Browse our assorted dahlias for your next planting season.
FAQ
When should I start pinching my dahlias?
You should pinch your dahlias when they are between 8 and 12 inches tall and have at least four sets of leaves. This timing is critical because it allows the plant to establish a strong root system before it redirects its energy into growing side branches. Pinching too early can stunt the plant, while waiting too long can result in a woody main stem that is harder to branch. If you're not sure how your garden fits into the bigger picture, check the Hardiness Zone Map.
Why does my dahlia have plenty of leaves but no flowers?
This is usually caused by one of two things: too much nitrogen or not enough sunlight. High-nitrogen fertilizers encourage the plant to grow lush, green foliage at the expense of flower buds. Ensure you are using a fertilizer with higher phosphorus and potassium levels. Additionally, make sure your plants are getting at least 6 to 8 hours of direct, unobstructed sunlight every day. For a broader planning overview, All About Dahlias is a helpful companion guide.
Does cutting the flowers really make more grow back?
Yes, cutting flowers is essential for continuous blooming. A dahlia's biological goal is to produce seeds. Once a flower fades and starts developing seeds, the plant sends signals to slow down the production of new buds. By cutting the flowers for bouquets or deadheading them as they fade, you "trick" the plant into continuing to produce more buds in its ongoing effort to make seeds.
Should I fertilize my dahlias every week to get more blooms?
No, fertilizing every week is usually too much and can lead to a buildup of salts in the soil or excessive leafy growth. For most dahlias, a high-quality, low-nitrogen fertilizer applied every 3 to 4 weeks is sufficient. Always water your plants well before and after applying fertilizer to help the nutrients reach the roots and to prevent root burn. Before you place an order, review our Shipping Information.
