Dahlias in the Cut Flower Garden
Dahlias are an absolute must for the cut flower garden. Do you love the idea of snipping flowers from your very own yard to make florist quality hand tied bouquets? It’s the best, right?! You need to add dahlias to your cut flower garden this summer. And I’ll help you get the most bang for your Dahlia buck by starting your Dahlias early!
How to Grow Dahlias
Some flowers, like zinnias and sunflowers, grow from seeds. Other flowers, like ranunculus, grow from corms. Dahlias, on the other hand, grow from tubers.
Dahlia tubers look similar to potatoes. Picture a potato with a stem. In order for your tuber to grow, you need to have a body (the potato looking piece) with a neck and an eye. The eye can be a tiny bump…that’s where your new plant will grow.
Dahlias love full sun and warm weather. If you can dig a small hole, you can grow dahlias! There’s not much to it.
Where to Buy Dahlias for a Cut Flower Garden
The cool thing is you can buy dahlia tubers at just about any nursery, including Lowes and Home Depot. You can pick them up in bags in late winter/early spring, and plant them in the garden after your last frost. A few weeks later you’ll see green shoots and get blooms in July or August.
Another option is to order dahlia tubers online. While I do make the occasional impulse buy at Lowes, I order 95% of my dahlias from Longfield Gardens. I love ordering online due to the vast options in dahlias. You can choose for colors, plant height, growth habit, and bloom shape. Also, most online stores will send your dahlias in the mail when it’s time for your specific planting time.
If you’re new to growing dahlias and you want a small cutting garden, I would suggest picking about 3 dahlia varieties. Many dahlias are sold in pairs, so that would give you 6 plants.
Be sure to choose coordinating colors in different shapes. That way, when the dahlias bloom, you can choose any flower from your cut flower garden to make a gorgeous, coordinating, mixed bouquet.
Early Dahlia Blooms for a Cut Flower Garden
You can absolutely plant your dahlia tubers directly in the ground when all threat of frost is gone. Some people suggest waiting an additional 2 weeks for the soil to warm up. Dahlias like it hot!
I, however, am cheap/frugal and like to maximize my flower potential. I want flowers from June through October! And if I plant in mid-May, I won’t have flowers until sometime in mid or late July.
I prefer to get a jump on the season by starting dahlias in pots about 4-6 weeks before my last frost. For reference, I live in Pittsburgh, PA. It’s a zone 6, where my last frost is roughly mid-May. I start “pre-sprouting” my dahlias in April. Mid-April is perfect.
So how is it done? Fairly easy and without anything special if that’s how you role!
I like to use old plastic pots from perennials I bought in previous years and whatever soil/potting mix/compost I have on hand. Simply throw some potting mix in a pot with holes (you need drainage to avoid rotting the tuber), add the tuber, put a bit more soil in, and wait for your flower to grow. I keep the potted plants in a plastic bin in my warm basement until they begin to grow. Then it gets fun! Don’t worry, I’ll explain more.
If you don’t have leftover flower pots, you can use any container that drains (has holes) and holds soil. Large yogurt and cottage cheese containers work well for small tubers. Gallon milk/water jugs with the top portion cut off would work for bigger tubers. Just remember to poke holes in the bottom so water can drain. But because these are in our houses, we have to keep the pots in a bigger water tight container so our house isn’t covered with dirty water. I like to use big storage totes to keep several pots in at a time.
Pre-sprouting Dahlias for a Cut Flower Garden
When you get your tuber and you’re ready to pre-sprout (that simply means we are putting them into some soil to start the growing process), it may look a little shriveled. But that’s okay.
Gather your supplies! Pots with drainage holes, potting mix, dahlia tubers, snips, and plant tags.
Step 1
What you want to do is remove any tubers that are dangling / broken. Just a quick snip will get rid of those. They won’t grow and could risk rotting, therefore hurting the rest of the plant.
Step 2
Next we are going to fill our predrilled pots with a couple inches of potting mix.
Try to get potting mix without added fertilizer. Or if you have compost at home, you can use that too. You can use straight compost, or mix it with peat moss and perlite.
Don’t get hung up on what “soil” you’re using. I’ve used potting mix, cow manure, my own compost, dirt from the ground mixed with equal parts peat moss and some perlite – – I use what I have or what I have access to. I do try to avoid anything with added synthetic fertilizer as I’m trying to help my native soil/ecosystem. But that’s up to you.
On this day I am using bagged “garden soil” and perlite to help lighten it and facilitate drainage.
Step 3
Place your tuber, with the eye facing up, on the soil you just put in the pot. Then cover with just enough soil that the tuber is covered.
We aren’t burying deep because A) dahlias only like to be buried with 1-2″ of soil over them, and B) we want to see quickly when the plant begins to grow.
Also, we aren’t going to water these until we see life. The tuber is dormant and doesn’t need much moisture yet. We are waking it up with the warmth of our house. Not water. However, if your potting mix was completely dry, you can ever so lightly add a bit of water.
And that’s it for planting! In about 4 weeks you’ll have a dahlia plant, like the one below, ready for the garden.
When Pre-sprouted Dahlias Begin to Grow
When you see the first signs of life (the plant is shooting up a stalk) it’s time for a bit of water, and a bit of light.
So here’s the thing. If you have a grow light, or an LED shop light, you can place your dahlia under the lights. I don’t have space under my lights so I take my dahlia pots outside.
Dahlias need warm temperatures. But spring isn’t always warm. So you have a couple of options.
On warm days, you can place your dahlias outside in the sun. But on cooler days, like below 55, I’ll place them outside with frost cloth over them, or with a clear plastic tote placed over them.
When the day is ending, bring the plants back inside to keep them warm at night.
And repeat this every day until the nights stay above 50 degrees.
Some years I will set up my cheap plastic “greenhouse” and just pop the plants in there until mid-may. I still watch the nighttime temperatures. If the temperature is dipping below freezing, I’ll bring the plants inside just to make sure they survive.
Dahlias foliage will “melt” at freezing temperatures. So make sure you don’t leave your plant outside at night if the temperature dips to 32 or below.
Planting Dahlias in the Cutting Garden
When you no longer have frost at night, it’s time to plant! Dig a hole about 6″ deep, place your dahlia in the hole, and cover with soil.
It’s a good idea to place a stake in the hole when you plant your dahlia in the cutting garden. Most dahlias suitable for cutting are over 36″ tall. They can start to flop over. It’s a good idea to get a stake in early so you don’t accidentally spear a tuber.
I like to stake dahlias individually. Every dahlia gets tied to its own stake. If you have a fence, dahlias can be tied to the fence and look beautiful from both sides.
You can space your dahlias about 12″ to 18″ apart. If you are going to be cutting a lot, then place each plant about 12″ apart and watch as they grow into a spectacular show!
I hope you decide to add dahlias to your garden this year! Whether you add dahlias to your cut flower garden or to your landscape, I think you’ll be in love!
Are you starting a cut flower garden this year? I’d love to know in the comments below. Thanks for stopping by!
