How to Stake Dahlias (The #1 Mistake Beginner Gardeners Make)
- Megan Haworth
- Mar 17
- 4 min read
Dahlias grow into tall, top-heavy plants that often reach 4–5 feet tall. Without support, wind and rain can easily knock them over. In this guide, I’ll show you several simple ways to stake dahlias so they stay upright and produce beautiful blooms all summer.
If you're new to growing dahlias, you may also want to read the earlier posts in this series:
Today we’re talking about one simple step that can make a big difference in how your plants perform.
The Most Common Dahlia Growing Mistake
If there is one mistake that is more common than any other when growing dahlias, it’s not staking them.
It’s an easy mistake to make.
You plant this little 5-inch tuber in the ground or in a pot, and it’s hard to imagine that it will turn into a plant that may grow four or five feet tall, with a main stalk two to three inches thick near the ground.
But I promise you, it will.
By mid-summer, dahlias become large plants loaded with blooms. Without support, tall stems can easily flop over in wind or heavy rain.
And once a plant falls over, it’s hard to recover.
The Second Most Common Staking Mistake
Even gardeners who remember to stake their dahlias sometimes run into another problem:
The stake isn’t strong enough.
I’ve had thin wooden bamboo stakes snap in half under the weight of a mature dahlia plant.
Dahlias are surprisingly heavy plants once they’re in full bloom, so whatever support you choose needs to be sturdy enough to handle the plant at its full size.
How I Support Dahlias in My Flower Field
In my dahlia field, where I grow hundreds of blooms for local florists, I stretch trellis netting between strong metal T-posts. This creates a sort of web that the dahlia plants grow up through as they mature.
If you're planning to grow dahlias in a cutting garden, this method works really well because it allows you to support many plants at once.
The Easiest Way to Stake Dahlias for Beginners
If you're new to growing dahlias, the simplest method is using one strong stake per plant. A metal T-post or strong tomato stake works well. Drive the stake into the ground when you plant the tuber, then loosely tie the plant to the stake as it grows throughout the season.
This method is easy, inexpensive, and works well for most home gardens.
Staking Options for Home Gardens
In my landscape garden, I prefer options that are a little more visually pleasing than plastic netting and t-posts. Here are some methods that work well for home gardeners.
Tie dahlias to nearby structures
Grow dahlias near something sturdy like a lamp post or mailbox and gently tie the main stalk to it with garden twine as the plant grows.
Create a twine support system
Drive strong T-posts or heavy tomato stakes around a group of dahlias. Run garden twine around and between the stakes at about 18 inches and again at 36 inches to create a simple support grid that holds plants upright.
Use a tomato cage
Place a sturdy tomato cage around a single plant and allow the dahlia to grow up through it.
Stake each plant individually
Use one strong stake per plant and tie the stalk in as the plant grows taller.
Grow dahlias in containers
If you're growing dahlias in pots on your deck or patio, you can simply tie the plant to a deck railing as it grows.
Build a bamboo wigwam
Create a “wigwam” with bamboo stakes by tying them together at the top and allowing the plant to grow up through them.
This list isn’t exhaustive — there are lots of creative ways to support dahlias.
The key is simply making sure the support is strong enough.
When Should You Stake Dahlias?
Many growers install their supports at the same time they plant their tubers.
This has two advantages:
You won’t forget later in the season
You avoid accidentally spearing a growing tuber when adding stakes later
If you prefer to wait, just make sure you add support by June or July, when plants are about 1–2 feet tall.
Because nothing is sadder than a beautiful dahlia plant flopped over in a summer rainstorm with flowers in the mud.
Do Dahlias Always Need to Be Staked?
Most dahlias benefit from staking, especially varieties that grow taller than three feet. Larger decorative and dinnerplate dahlias almost always need support to keep stems upright and protect blooms from wind and rain.
What Happens If You Don’t Stake Dahlias?
Without support, dahlia plants often flop over during storms or when blooms become heavy. While plants sometimes recover, stems can bend or break and flowers may end up lying in the dirt.
Growing Dahlias This Year?
If you're planning your garden this season, you can browse the dahlia varieties I'm growing and sharing from my small flower farm.
Several varieties have already sold out, but there are still beautiful options available.