Step by step sowing of dahlias: from seed to flower

For most dahlias, you put a tuber in the ground to be sure that you see that particular variety bloom. Tubers are always true to type. This means that, even if you take cuttings from them, they always produce the same variety. But did you know that you can also sow dahlias ? It is fantastic to sow them in March and see them bloom for the first time that same summer. What makes sowing so special is that you are never sure what you will eventually see. Each seed contains a different gene and is therefore unique. Cross-pollination makes it impossible to get the same flower as the mother plant. It is like playing the lottery. And I think that is fantastic. There is something magical about not knowing what will happen. At the beginning of summer I look at the flowers from their buds. Not all dahlia seedlings are equally special, but they are always unique and therefore do not exist in theory.

New varieties are created through manual or natural cross-pollination. Every variety on the market today was once a seed. Quite special, isn't it? Through intensive selection by growers (dahlias often have to meet many requirements), gems are discovered. Only when a new variety remains stable for years, it is introduced and you can plant it in your garden.

There are two different ways to cross-pollinate . Either you let Mother Nature do her work, and let pollinators do the work, or you do the pollination manually - by hand. If you are just starting out with dahlias, it is much easier to let nature do her work. You only have to let some dahlias bloom and that's it. With manual pollination, you select 2 parent plants and then shield them with mesh, so that bees cannot get to the pollen. You often have to remove the upper petals to see the pollen. At the ideal moment, preferably around noon, you bring the two dahlias together and rub them against each other. It is not very exciting, this somewhat forced thing with dahlias, but it does ensure you have the right properties .

There is a good chance that you will see open flowers after sowing dahlias. The real pompom, ball and giant dinner plate dahlias are often a bigger challenge. Because our plants are often mixed together and there is a lot of cross-pollination, it is more likely that you will get open types . And you should not be sad about that, because bees, bumblebees and butterflies love those types of flowers. Due to the open heart, there is a lot of pollen and nectar available and that is exactly what these loyal allies in the garden are looking for. The more open dahlias, the more there is to eat. Because although I find those thick flowers of dahlias incredibly beautiful, it is the so-called single or open flowers that make my heart beat a little faster. The variation, the colours and the incessant visits of everything that floats and flies around in the garden: every summer and autumn I bounce with enthusiasm. The single dahlias are ideal garden plants, but slightly less suitable for keeping in a vase. They wilt faster because of the lack of many petals. Therefore, combine them both in the garden, then you have enough dahlias to pick and at the same time keep the bees, bumblebees and butterflies happy.

Dahlias produce dark brown to sometimes black seeds. They are quite flat with a small thickening at the back. Each seed has the potential to become a large plant with large tubers and unique flowers. Sow dahlias from the end of March and the beginning of April . Do not start too early, because dahlia seedlings are known to grow quickly.

It takes an average of 1 week for the seeds to germinate and another week to a week and a half before the first real leaves appear. At that point, quite a few roots have formed and you can give each plug its own pot. P9 pots are very suitable. At that stage, I use peat-free potting soil to let the seedlings grow further until they can go into the ground in May. Dahlia seedlings grow very quickly and only need 4 to 6 weeks to evolve from seed to plant. Keep in mind that they are sensitive to frost and, like the tubers, cannot tolerate frost.

The rest of the process is similar to that of pre-grown dahlias. Plant in the ground, about 30 to 40 centimetres apart, water well, mulch and you're done. Feel free to also add some well-rotted manure or lava meal to the planting hole, which will benefit the growth of the plant. In theory, you could plant seedlings much closer together. This is mainly done by breeders, because they have hundreds, if not thousands of seedlings in the hope of being able to select a few promising ones. Because make no mistake: not every seedling will make it in the end. Strict selections precede this. Usually, people choose on the basis of colour, shape, firmness of the flower stems, closed hearts and so on. In that case, most breeders apply the principle of "kill your darlings" . It is impossible to keep them all. But let's be honest, we hobbyists mainly want to enjoy them. It doesn’t always matter whether a flower produces completely closed hearts or forms large stems, because they would do better in bouquets. It is the run-up to the first flower unfolding, the process from seed to flower, that makes it interesting and very captivating. It is pure magic when you consider that after 1 season, because I probably haven’t told you that yet, you already get to see flowers. I put seeds in the ground in the spring with the intention of being surprised by what color or shape the dahlia will eventually be. It feels a bit like playing the lottery every year. With the exception that in this game you always win of course.