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 trtue to the mother plant, so every seed is a new and unique variation. 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 flowers, it is truly amazing, and you can keep the variations you like, dig up that dahlia tuber, and propagate for more.
The 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.
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.
Dahlia is a perennial plant native to Mexico; bushy, tuberous, herbaceous and revered for their amazing beauty. A member of the Asteraceae (or Compositae), dicotyledonous plants, related species include the Sunflower, Daisy, Chrysanthemum, and Zinnia. There are 42 species of dahlia, with hybrids commonly grown as garden plants. Flower forms are variable, with one head per stem; these can be as small as 2″/5cm in diameter or up to 12″/ 30cm (The dinner plate variety).
Dahlias grow naturally in climates which are frost free (USDA Zone 8), and they are not adapted to withstand below freezing temperatures. But their tuberous nature enables them to survive long periods of dormancy. This characteristic means that gardeners in temperate climates with frosts can grow dahlias successfully, as long as the tubers are extracted from the ground and then stored over the winter in a frost-free environment. Planting the tubers quite deep can also provide frost protection. When in growth season, modern dahlia hybrids require free-draining soil, and thrive in maximum sunlight. Taller cultivars typically require some form of staking as they grow, and all garden dahlias need deadheading regularly, once flowering commences, to continue blooming throughout the entire season.