Ok, ok, out of all the flowers we grow, dahlias are our absolute favorite. We have learned quite a bit over the years, and these beautiful ladies are hard to maintain during the hot, hot central California summer. This page and all. our posts are dedicated to those who love these beautiful flowers and want to grow them in the garden to adorn their landscape, as well as cut them for amazing flow bouquets.
Last year was the first year we grew dahlias from seed and I am hooked! This method of dahlia propagation is simple, and creates a great surprise in spring. Why? Dahlia seeds are not true to the mother plant, so every seed is a new and unique variation. You never know what kind you will get! The only way to get a true replica of your mother plant is to divide the tuber, or take cuttings (Dahlia Propagation Through Cuttings article). You get such a broad and wide range of dahlia flowers from planting seed, it is truly amazing, and you can keep the variations you like, dig up that dahlia tuber, and propagate for more.
The Steps – Growing Dahlias with Seed
The dahlia from seed method is simple, and the dahlia seeds grow fast. Here is how to propagate dahlias from seed:
Find a pot or seed tray and fill it with a seedling mix or a mix of soil and vermiculite.
Wet the medium and pock holes with a seed planter/dibber that are about 1/2″ deep, and about an inch or so apart.
Place your seeds in the holes and cover with soil mix.
The seeds will germinate in about 2 weeks, but if you apply bottom heat with a seed mat, it will speed up the process (This season mine popped in 7 days).
Water daily, and provide plenty of light, either with a grow light or place in a south facing window.
Soon you will have a whole set of seedlings.
Once they are about 2-3 inches or their leaves are touching, you can move them to small pots (3 inches) and continue to grow.
Before you move the little propagated dahlias to the garden, “harden them off” by exposing them to the outdoors, gradually over a week more and more.
Pro Tip – When the dahlias you grow from seed are 12-18″ tall, snip the center growth bud with garden snips/scissors. This will encourage branching and give you a bush with more flowers!
Wait for the fun!
These dahlias from seed will grow an amazing tuber you can lift if you like the variety you have produced. This tuber will produce the exact flower, and you can then use tuber division to multiply you bounty.
Starting to propagate my dahlias this week, and using a couple of techniques. In this article i will outline how I am taking tuber cuttings to multiply my stock. First off, at the beginning of my season, i put my tubers into containers indoors, and cover them about half-way with potting soil so i can catch all the action. Depending on the type, and the warmth, it usually takes a few weeks before the eyes start sprouting, and another one or two before i can start propagating the dahlias. Below is an overview of the technique:
Once the tuber has a number of sprouts, I select ones that are 3 or 4 inches in height for my cuttings.
Tuber with multiple shoots for taking cuttings for propagation
2. Once I have selected a Dahlia shoot with two sets of leaves, I then use a sharp instrument (Exacto Knife), to take a cutting. Note: You want to get a bit of the dahlia tuber at the base to insure the best chances for rooting.
Take a bit of the Dahlia Tuber with the cutting
3. I take off the bottom set of leaves once I have the cutting.
Dahlia cutting with a bit of tuber and lower leaves removed
4. This step is optional, but if you have rooting hormone, it can aid in getting the dahlia cutting to root more quickly.
Dip the Dahlia cutting in rooting hormone for improved success rates
5. Finally, take your cutting and place it in a mix of soil and vermiculite. The loose soil will give roots free reign, and encourage growth. Note: I also apply bottom heat and cover the cuttings with plastic to create a complete propagation environment.
The propagated cutting ready to grow.
In about two weeks or so, the baby Dahlias will root. You can check by gently tugging on the cutting.
Ground Temp: 60°F PH level: 6.5-7.0 Spacing: Bedding Dahlias – 9-12″, Small Flowering 2′, Large 3′ Depth: 6-8″ Time to Bloom: 8 weeks Notes: Do not water right after planting, wait till sprouts appear.