Table of Contents
- Introduction
- Build a Foundation for More Flowers
- The Secret of Pinching for More Stems
- Harvesting and Deadheading for Continuous Color
- Feeding Your Dahlias for Maximum Performance
- Water and Mulch for Stress-Free Blooming
- Choosing the Right Variety for Your Goals
- Bloom Size vs. Bloom Quantity (Disbudding)
- Managing Pests and Airflow
- Supporting Your Plants to Prevent Stem Breakage
- Late Season Care for Fall Blooms
- Conclusion
- FAQ
Introduction
There is nothing quite like the excitement of seeing the first dahlia buds swell and burst into color during the midsummer heat. Whether you are growing dinnerplate varieties as large as a dinner plate or petite border dahlias for a window box, the goal is usually the same: as many flowers as possible. These plants are incredibly generous, and with a few simple techniques, you can transform a single plant into a blooming machine that provides color from July through the first frost of autumn.
At Longfield Gardens, we want every gardener to feel the satisfaction of a garden filled with vibrant, healthy flowers, backed by our 100% Quality Guarantee. Helping your plants reach their full potential doesn't require a degree in botany; it just takes a bit of consistent care and an understanding of how these plants grow. This guide is designed for home gardeners who want to maximize their flower production and enjoy a season-long display of blooms.
By focusing on specific techniques like pinching, deadheading, and proper nutrition, you can significantly increase the number of flowers your dahlias produce.
Build a Foundation for More Flowers
Before we look at specific techniques to boost flower count, it is important to remember that a plant can only produce an abundance of flowers if its basic needs are met. Flowers require a massive amount of energy to produce, and that energy comes from the sun, the soil, and the water the plant receives.
Prioritize Full Sun
Dahlias are sun-loving plants that thrive in warm weather. To produce the most blooms, they need at least six to eight hours of direct sunlight every day. If a plant is grown in too much shade, it will spend its energy stretching toward the light, resulting in tall, spindly stems and very few flowers. If you find your dahlias aren't blooming well, the first thing to check is the amount of sunlight they receive.
Optimize Your Soil and Drainage
The health of the root system determines the health of the flowers. We recommend planting in fertile, well-drained soil enriched with organic matter. "Drainage" refers to how quickly water moves through the soil. Dahlias do not like "wet feet," which means their tubers should never sit in soggy ground. Adding compost to your garden beds before planting improves soil structure, helps with drainage, and provides the slow-release nutrients that support flower development.
Timing Your Planting
While it is tempting to plant as soon as the weather feels like spring, dahlias are tropical plants that need warm soil. We suggest waiting until the soil temperature reaches about 60°F before tucking your tubers into the ground. For a step-by-step refresher, see How to Plant Dinner Plate Dahlia Tubers.
Key Takeaway: Success starts with the basics. A dahlia planted in a sunny spot with well-drained soil will always have more energy to dedicate to flower production than one struggling with shade or poor drainage.
The Secret of Pinching for More Stems
If you only do one thing to increase your dahlia blooms, make it "pinching." This simple technique sounds counterintuitive because it involves cutting off part of a healthy plant, but it is the single most effective way to multiply the number of flowers you get.
How Pinching Works
Left to its own devices, a dahlia will usually grow one tall, central stalk. This stalk will produce a flower at the top, and while some side branches will eventually form, the plant will remain somewhat vertical and limited in its bloom capacity.
When you "pinch" or cut off the top of that main center stem, you disrupt the plant's vertical growth. This signals the plant to send its energy into the dormant buds located lower down on the stem. These buds grow into new lateral branches, turning one main stem into four, six, or more. More branches mean more places for flower buds to form.
When and How to Pinch
Wait until your dahlia plant is about 12 inches tall and has at least four sets of leaves. Using a clean pair of garden shears or your fingers, snip off the very top of the center shoot, just above the highest set of leaves. You only need to remove about 2 to 3 inches of the stem.
Within a week, you will see new shoots emerging from the leaf axils (the spot where the leaf meets the stem). This results in a bushier, sturdier plant that can support a much higher volume of flowers.
What to do next:
- Monitor your plants once they reach 10–12 inches in height.
- Locate the central growing tip.
- Clean your snips with rubbing alcohol to prevent the spread of garden diseases.
- Make a clean cut just above the top set of leaves.
- Observe the new side growth over the following two weeks.
Harvesting and Deadheading for Continuous Color
Dahlias have a biological "reset button" that you can use to keep them blooming. The plant’s primary goal is to produce seeds to ensure the next generation. Once a flower fades and begins to form a seed pod, the plant slows down its flower production. By preventing seed formation, you trick the plant into thinking it still needs to produce more flowers.
The Power of the Bouquet
One of the best ways to increase blooms is actually to cut the flowers for bouquets. Dahlias are among the most productive cut flowers in the world, and How to Cut Dahlias for Long Stems explains how to harvest them for the best vase life. When you cut a stem to bring it indoors, you are essentially deadheading the plant before the flower even fades. This encourages the plant to immediately start working on the next bud.
When harvesting, cut the stems long. Don't be afraid to cut deep into the plant, back to a point just above where a new set of leaves or buds is emerging. This keeps the plant's shape tidy and encourages longer, stronger stems for your next bouquet.
Proper Deadheading Technique
If you don't cut the flowers for vases, you must remove them as soon as they start to fade. This is called deadheading. It is important to distinguish between a new bud and a spent flower head, and How to Deadhead a Dahlia Plant shows the easiest way to do it.
- New Buds: Usually round or slightly flattened on top, firm, and green.
- Spent Flowers: Often cone-shaped or pointed, and they may feel soft or mushy when squeezed.
To deadhead correctly, don't just pull off the petals. Follow the flower stem all the way back to the main branch and cut it there. This prevents "dead stubs" from remaining on the plant, which can attract pests or look unsightly.
Key Takeaway: The more you cut, the more they bloom. Frequent harvesting and diligent deadheading prevent the plant from going to seed, ensuring a steady supply of new buds until the first frost.
Feeding Your Dahlias for Maximum Performance
While dahlias can grow in average soil, they are "heavy feeders," meaning they require plenty of nutrients to sustain their rapid growth and prolific blooming. However, not all fertilizers are created equal. The type of food you give your plants will determine whether you get a giant green bush or a plant covered in flowers.
Understanding the Numbers
Fertilizers are labeled with three numbers (NPK), representing Nitrogen, Phosphorus, and Potassium.
- Nitrogen (N) promotes green, leafy growth.
- Phosphorus (P) supports root development and flower production.
- Potassium (K) helps with overall plant health and tuber development.
Early in the season, a balanced fertilizer (like a 10-10-10) is fine to help the plant get established. However, once the plant is about a foot tall and starting to set buds, you should switch to a fertilizer that is lower in nitrogen and higher in phosphorus and potassium, and When to Fertilize Dahlia Plants for Bigger, Better Blooms lays out the timing in detail.
Avoid Too Much Nitrogen
Using a high-nitrogen fertilizer (like those often used for lawns) late in the season is a common mistake. Too much nitrogen will result in lush, beautiful green foliage but very few, or even zero, flowers. If your plant looks like a giant green hedge with no buds in sight, it likely has too much nitrogen and needs a boost of phosphorus.
Feeding Schedule
We recommend feeding your dahlias about once a month during the growing season. If you are using a water-soluble fertilizer, you can apply it every two weeks. Always follow the instructions on the product label, as over-fertilizing can be just as harmful as under-fertilizing.
What to do next:
- Check your fertilizer label for the N-P-K ratio.
- Switch to a low-nitrogen formula once buds appear.
- Apply fertilizer to the soil around the base of the plant, not the leaves.
- Water the plant thoroughly after applying granular fertilizer to help it reach the roots.
Water and Mulch for Stress-Free Blooming
A thirsty dahlia is a stressed dahlia, and stressed plants do not produce many flowers. Consistent moisture is essential for keeping the plant’s "plumbing" working correctly so it can transport nutrients from the soil up to the developing buds.
Water Deeply, Not Constantly
Instead of a light daily sprinkle, dahlias prefer deep watering once or twice a week, depending on your weather, and How Often Should I Water My Dahlia Bulbs? covers the basics. "Deep watering" means providing enough water so that it soaks several inches into the ground. This encourages the roots to grow deeper, making the plant more resilient during hot, dry spells.
The best way to tell if your dahlias need water is to stick your finger an inch or two into the soil. If it feels dry, it’s time to water. If it still feels moist, wait another day. Using a soaker hose or drip irrigation is ideal because it keeps the water at the root level and keeps the foliage dry, which helps prevent powdery mildew.
Use Mulch to Conserve Moisture
Mulching is a simple win for any dahlia grower. A two-inch layer of organic mulch, such as shredded bark, compost, or clean straw, helps keep the soil cool and moist. This reduces the frequency of watering and prevents the soil from baking under the hot summer sun. Keep the mulch a few inches away from the main stem of the plant to ensure good air circulation and prevent rot.
Choosing the Right Variety for Your Goals
Not all dahlias are designed to produce the same number of flowers. If your primary goal is to have the highest "bloom count" possible, the variety you choose matters.
Productive Varieties
Generally, smaller-flowered dahlias like Ball Dahlias tend to produce more individual flowers per plant than the giant dinnerplate varieties. Varieties like Dahlia Ball Cornel (a classic red ball dahlia) or 'Natal' (a deep burgundy pompon) are famous for their productivity.
The Dinnerplate Trade-Off
Dinnerplate dahlias, such as Dahlia Dinnerplate Cafe Au Lait or 'Emory Paul,' produce magnificent, massive blooms, but they produce fewer of them. Because the plant has to put so much energy into making one 10-inch flower, it can't produce 50 of them at the same time. If you want a high volume of flowers, consider mixing some smaller ball or decorative types into your garden alongside the giants.
Border Dahlias for Constant Color
If you have a small space or want flowers for the front of a garden bed, "border dahlias" are an excellent choice. Dahlia Border Decorative Gallery Art Deco & Gallery Singer stays short and blooms heavily from midsummer to frost compared with taller dahlia types.
Key Takeaway: Match your variety to your expectations. Choose ball, pompon, or cactus dahlias for high-volume flower production, and save the dinnerplate varieties for when you want a few show-stopping focal points.
Bloom Size vs. Bloom Quantity (Disbudding)
Depending on your preference, you can choose to have many smaller flowers or a few very large ones. This is controlled by a technique called "disbudding."
How to Disbud
Dahlias typically grow buds in clusters of three. There is one large "terminal" bud in the center and two smaller "lateral" buds on the sides.
- For more flowers: Leave all three buds alone. All three will eventually bloom, giving you a cluster of flowers.
- For larger flowers: Use your thumb and forefinger to gently snap off the two side buds, leaving only the center one. The plant will now direct all the energy that would have gone to three flowers into that one single bloom, making it much larger and stronger.
Disbudding is particularly popular for dinnerplate varieties where the goal is maximum size. For most home gardeners who just want a colorful yard, leaving all the buds to bloom naturally is the preferred approach.
Managing Pests and Airflow
A plant that is struggling with pests or disease will naturally produce fewer flowers. Keeping your dahlias healthy is a proactive way to ensure they keep blooming.
Support Good Airflow
As dahlia plants grow thick and bushy, air can have a hard time moving through the center of the plant. This creates a humid environment where diseases like powdery mildew can thrive. To prevent this, we recommend thinning out some of the foliage at the bottom 12 inches of the plant once it is well-established. Removing the lower leaves allows air to circulate and keeps the plant drier and healthier.
Keep Pests at Bay
Slugs and snails love tender young dahlia shoots, and earwigs or thrips can sometimes damage developing flower buds. Keeping the area around your plants free of weeds and fallen debris removes hiding spots for these pests. If you notice chewed leaves or distorted buds, check your plants in the evening with a flashlight to identify the culprit. For most home gardens, simple manual removal or a gentle insecticidal soap is sufficient to keep pests from ruining the flower show.
What to do next:
- Strip the leaves from the bottom 10–12 inches of mature plants.
- Space your plants at least 18–24 inches apart to ensure good air movement.
- Check the center of the plant for any yellowing or diseased leaves and remove them promptly.
- Avoid overhead watering late in the evening to keep leaves dry overnight.
Supporting Your Plants to Prevent Stem Breakage
There is nothing more disappointing than seeing a dahlia plant loaded with buds snap in a summer thunderstorm. Because dahlias produce so many flowers, they can become very top-heavy, especially after a rain. For a clearer sense of the sizes involved, see How Tall Do Dahlia Plants Get?.
Staking is Essential
Most dahlias that grow over 3 feet tall need some form of support. Staking your plants early ensures that the stems stay upright and the flowers stay off the ground.
- Single Stakes: A sturdy wood or metal stake driven 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: A simple and effective way to support bushier varieties.
- Coring: For large beds, some gardeners use a horizontal netting system that the plants grow up through.
By providing support, you ensure that the plant’s energy goes into making flowers rather than trying to stay upright or recovering from broken branches.
Late Season Care for Fall Blooms
Dahlias often have their best "performance" in late August and September when the nights begin to cool down. To keep the momentum going during this time, keep up with your watering and deadheading.
As the season winds down in September, you can stop fertilizing. This encourages the plant to start shifting its energy away from flower production and back down into the tubers for winter storage. However, keep deadheading right up until the first frost. The plants will continue to try and bloom as long as the weather stays above freezing.
Conclusion
Increasing your dahlia blooms is a rewarding process that combines a bit of "tough love" early in the season with consistent care throughout the summer. By starting with the right foundation of sun and soil, and then using techniques like pinching and deadheading, you can enjoy a garden that is overflowing with color. Remember that gardening is a journey, and every season is an opportunity to learn what works best in your specific soil and climate. If you'd like a climate reference, the USDA hardiness zone map can help.
- Pinch early: Cut the center stem at 12 inches to create a bushier plant with more flower-bearing branches.
- Deadhead often: Remove spent flowers to keep the plant's energy focused on new buds.
- Feed correctly: Use a low-nitrogen, high-phosphorus fertilizer once the plant is established to promote flowers over foliage.
- Harvest regularly: Bringing flowers inside for bouquets is one of the best ways to keep the plant productive.
"Dahlias are among the most generous plants in the garden. The more attention you give them through pinching and harvesting, the more they will reward you with a spectacular display of color."
We hope these tips help you create the most beautiful dahlia garden yet. For more inspiration and to find the perfect varieties for your home, we invite you to explore the resources available at Longfield Gardens and review our shipping information. Happy planting!
FAQ
Does pinching really make a difference in how many flowers I get?
Yes, pinching is one of the most effective ways to increase bloom count. By removing the main growing tip when the plant is young, you force it to grow multiple side branches. Each of these new branches will eventually produce its own set of flowers, effectively doubling or tripling the potential for blooms compared to a plant that is never pinched.
Why does my dahlia have lots of leaves but no flowers?
This is usually caused by one of two things: too much nitrogen or not enough sun. Nitrogen encourages the plant to grow green leaves and stems, but it can suppress flower development if there is too much of it. Additionally, if the plant isn't getting at least six hours of direct sunlight, it may not have enough energy to produce buds.
Should I cut the flowers even if I want them to stay in the garden?
If you want the plant to keep producing new buds, you must remove the old ones. Whether you cut them for a vase or deadhead them once they fade in the garden, the result is the same: it prevents the plant from making seeds. Preventing seed production is what keeps the plant in "blooming mode" for the entire season.
Is it better to water dahlias in the morning or the evening?
Morning is generally the best time to water. This allows the soil to soak up the moisture before the heat of the day, and any water that gets on the leaves has time to dry off in the sun. Watering in the evening can leave the foliage wet overnight, which increases the risk of fungal issues like powdery mildew.