Dahlias are one of the most vibrant and beautiful flowers you can grow in your garden. With their bright colors and unique shapes they bring so much joy and summertime charm. As a dahlia lover myself I’m always looking for ways to maximize the number of breathtaking blooms from my plants. One technique that really helps is pinching the dahlias.
What Is Pinching Dahlias?
Pinching simply refers to pruning the top few inches off the main stem when the plant is still young. This damages the stem tip and forces the plant to redirect its energy into growing side shoots and branches lower down. It kickstarts increased branching and fuller, bushier growth.
Why Should You Pinch Your Dahlias?
There are several great benefits to pinching dahlia plants
- Promotes bushier, multi-branched plants instead of tall, spindly ones
- Results in stronger, sturdier stems that can better support the heavy flowers
- Significantly increases the number of blooms each plant produces
- Creates a fuller, more abundant floral display overall
- Keeps plants more compact and manageable in size
So pinching is an easy way to maximize your harvest from each dahlia and have plants overflowing with colorful flowers. But there is a point where it becomes too late in the season to pinch them.
When Is The Optimal Time To Pinch Dahlias?
The key to success is pinching at the right time – not too early but not too late either. The ideal window is when plants are around 8-12 inches tall and have 3-4 sets of true leaves formed.
This generally occurs 4-6 weeks after transplanting young seedlings outdoors in spring. For tubers it’s about 4-6 weeks after they have sprouted.
Pinching during this stage allows the plant time to recover and generate side shoots before summer heat causes it to bolt upwards. It’s late enough that you don’t stunt growth but early enough to shape the plant while stems are still pliable.
How Can You Tell It’s Too Late To Pinch?
Avoid pinching dahlia plants once they exceed 18 inches in height. At this point, the stems have hardened off and pinching will create too much stress.
Here are signs it’s too late for pinching:
- Plant height exceeds 18 inches
- Thick, woody stems have developed
- Flower buds are visible on the central stalk
- Midsummer heat has arrived
Pinching a mature plant will shock and delay flowering significantly. The new growth won’t have time to mature and bloom before frost arrives.
What Are The Consequences Of Pinching Too Late?
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Delayed flowering – Removing the main growing tip late interrupts the bloom cycle too close to fall.
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Fewer blooms – New shoots may not mature fast enough to produce flowers before first frost.
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Weaker regrowth – Young shoots in summer heat are more vulnerable to pests/disease.
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No seeds – Late blooms won’t get pollinated in time to form viable seeds.
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Smaller tubers – The plant can’t send extra energy to enlarge roots for overwintering.
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Floppy stems – Pinching off top-heavy stems late causes remaining plant to topple over.
Tips To Avoid Pinching Dahlia Plants Too Late
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Mark your calendar with target pinch date after transplanting/sprouting
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Monitor height weekly once 6 inches tall to catch ideal window
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Pinch at 12 inches even if less than 4 sets of leaves to avoid missing prime time
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Feel stems – optimal pliability for pinching is when still green vs. woodening
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Err on the side of pinching a bit too early (8 inches) rather than too late
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Simply stake tall, unpinched plants instead of pinching if you already missed the window
What Should You Do If You Missed The Pinching Window?
If your dahlias are already too mature to pinch this year, don’t worry! Here are some alternatives:
- Stake or cage plants to support lanky stems and prevent flopping
- Prune back side shoots to outward facing buds to encourage bushiness
- Mound soil/mulch around lower 6 inches of stem to stimulate new roots and shoots
- Deadhead spent blooms to redirect energy into new buds
- Reduce water & fertilizer to slow rapid late season stretch
- Plan to pinch newly sprouted tubers properly next spring
The most important thing is to avoid pinching if you have any doubts about timing. Tall, unpinched dahlias will still give you a bountiful late summer display. But pinch too late, and you risk harming next year’s plant as well.
Be patient, learn your dahlias’ growth habits, and focus on mastering proper pinching technique for your climate. With practice, you’ll get a feel for the perfect stage to pinch your plants for maximum flowers. Then you can pinch with confidence and enjoy a spectacular dahlia garden!
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There are a lot of small things you can do which make huge gains in your gardening, pinching out the growing tips on some plants is on of these easy wins.
For new gardeners, the idea of pinching or snipping off the top of a plant can be terrifying. Especially when you’ve put so much time and effort into nurturing and caring for that plant, so let me talk you through why you might choose to “pinch out” and how to go about it, to help you decide if it’s for you.
What Is Pinching Out?
Very simply, pinching out is when you snap or cut the very top of the plant stem, above a set of leaves in order to encourage the plant to change its growing habit. In this case, with dahlias, when you have a plant which would naturally grow very tall with few stems which produce flowers at the end, we are encouraging the plant to grow more stems and therefore more flowers rather than just allowing nature to take its course and produce a tall plant with less blooms.
It works by activating the growth hormone in that plant stem which sends the plant into temporary overdrive in producing shoots at other points in the stem. Because we are forcing the plant to focus on growing more shoots rather than flowers, it will delay your flowering for a few weeks, but in the long run, the plant will produce a lot more blooms.
How to pinch dahlias for more flowers!
FAQ
How late can you pinch out dahlias?
The best time to pinch a dahlia is when it’s between 12″ and 16″ tall and has at least 4 sets of leaves on the center stalk. At this point the plant is growing rapidly and will quickly recover from being pinched.
Does cutting dahlias encourage more flowers?
Harvesting dahlias with nice, deep cuts is a form of pinching. It re-directs the dahlia plant’s energy into 2 areas: producing more side-shoots (eventually more flowers) and producing more tubers. Don’t be afraid to cut your dahlias deeply for healthy plants, more blooms, and long strong stems.
When should you pinch a dahlia?
Typically, it is best to pinch a dahlia when it reaches 12 to 16” in height for plants that are sturdy. Plants that aren’t pinched in time will grow too tall and spindly. Ignore the plant for too long and it will flop over because it has grown too tall. For the best results, be sure to pinch your Dahlias before they reach 14”.
Can a dahlia plant grow without pinching?
Allowing the dahlia plant to grow naturally without pinching it will result in a tall, skinny plant with very few blooms at the top. Although several lateral buds may bloom, there will be fewer of them than if the plant is pinched.
What happens if you pinch a dahlia plant?
If you pinch a dahlia plant early in its growth, it will produce two shoots on either side of the cut. This is similar to pinching snapdragons and sweet peas, and results in a stronger, more balanced base stem. Each stem will produce the same number of blooms as the original, giving you twice as many flowers!
What is pinching a dahlia?
Pinching is a technique often used on dahlias to produce the best results for fuller plants with many large beautiful blooms. If you want to double or triple the number of blooms in your garden, this is one of the growing tips you need to know!
How do you pinch a dahlia plant?
You must continue pinching your plant to ensure new growth and more blooms. Ultimately, it doesn’t have to be difficult to pinch your dahlia plants. Again, you’ll want to wait until the plants reach 12 or 16” in height. Then, you should grab a pair of scissors or shears. You can also use your fingers. Be careful not to tear the plant’s steam.
When should you top a dahlia plant?
Individuals interested in growing dahlias need to know when to top their plants. Otherwise, the plant will grow tall and out of control. If it gets too tall, it’ll fall over. For optimum results, you should try pinching or topping your dahlias once they’ve reached 12 to 16” in height.