The tubers of the dahlias must be dug up before winter and overwintered frost-free. From spring they are then planted out in the garden again to reveal their true beauty again. However, since the summer blooming plants cannot tolerate icy temperatures, you have to wait until winter is actually over. Only in permanently frost-free soil can dahlias sprout without problems and develop into stately plants at a rapid pace during spring.
Location
A sunny location offers ideal conditions for dahlias. The soil should be sandy and slightly acidic. Clay soils are not recommended for dahlias, as there is a risk of waterlogging here.
Ideal planting time
If you want to plant dahlias, you should first distinguish whether they are tubers, young plants or cuttings. Tubers are usually planted directly in the garden bed. Alternatively, it is also possible to put them in a bucket or a cold frame. In all cases, the time of planting is different. Once planted, dahlias should not be watered unless the soil is very dry or when planted very late.
Plant tubers outdoors
After the rest period in winter, dahlias can be planted in the bed from the end of April to the beginning of May. It is important that the
correct planting depth is maintained and the soil is somewhat dry (do not plant in the wet soil). If the likelihood of severe frosts is low, dahlias can also be planted a little earlier. But quite apart from the spring frosts, there is another reason against planting the too early Dahlias: In cold soil (especially when wet) the budding is delayed, so that the bulb and preformed eyes underneath To suffer. Dahlias planted later have a better start and grow faster.As a rule, the frosts that occur from the end of April are only short-term and superficial. Therefore, the tubers, which are five centimeters deep in the ground, do not need additional protection. If you want to be on the safe side, you can put an upturned flower pot over the planting area and secure it all around with a little leaves. If the dahlias are sprouting, the pot must be removed as soon as possible.
Tip: It is better to first plant very small dahlia tubers in pots and let them grow a little in the greenhouse (or a cool, bright room in the house). Then put them outdoors from mid-May.
Plant cuttings outdoors
Cuttings may only be planted outdoors after the ice saints, when there is practically no risk of frost. Since the cuttings do not initially have a tuber, but only fine roots, they would
Can't survive freezing temperatures.Plant in the cold frame or greenhouse
A greenhouse protects the freshly planted dahlias to a certain extent from cool temperatures. Insofar as the outside temperatures from the middle to the end of March only move around the freezing point to slightly minus degrees, they can - in one Planted in a pot - to be embedded in the ground in a cold frame, provided that they are later intended for planting in another bed. Transplanting dahlias that have already spread their roots in the ground is difficult because they are often damaged when they are removed. If the dahlias are to spend the whole summer in the cold frame, they can be planted directly in the ground.
Tip: Dahlias rarely suffer from soil fatigue. Therefore, they can be planted on the same beds over and over for years - provided that the soil is tilled properly and there is sufficient fertilizer.
Drive
To give the dahlias a good head start, many gardeners plant them in flower pots and early in the year place them up to the ice saints bright and cool but frost-free (garage window, cellar window, hallway or Glasshouse). In this case, the tubers can be planted in the flower pots or tubs from the end of February to mid-March. It is very important that the dahlias are bright.
Planting depth
Larger dahlia bulbs are inserted about a spade deep into the earth, so that they are only covered with a few centimeters of earth. Planted too deeply, their shoots first have to laboriously torture themselves into the light. If the layer of soil that covers the tuber is too thin, it does not grow well and is also not protected against light late frosts. The rule is: Cover with about a hand's breadth of loose soil.
Plant spacing
If the dahlias are planted in their final location, it is important to maintain the correct planting distance so that the plants can develop well and not light each other
and compete for land.- very tall varieties: 70 to 100 cm
- medium-high varieties (pompom, frill and ball dahlias): 60 to 70 cm
- low varieties (mignon, bed dahlias): 30 to 50 cm
Put tubers in water before planting?
Opinions are divided on this question. The fact is that the tubers are often very dried out after the wintering phase. For better growth, many gardeners recommend placing the tubers in room warm water for a few hours or even days. Nothing contradicts this philosophy as long as the weather at the end of April is warm and with little rain. However, if the garden soil is very damp - which is often the case in April - this procedure is not recommended. In the cold April soil there is a very high risk of rot for the tuber.
Divide the tubers
If the dahlias are older and the tubers are relatively large, they should be divided. Strong gardeners can break them apart by hand, it is easier with a knife. The interfaces do not need special treatment. However, it makes sense to let them dry out slightly before they get into the damp soil. A division is necessary because too many tuber parts interfere with each other when new, young tubers are formed. The shoots are then often only weak and small. The tubers should only be divided before planting, otherwise they will dry out during the long wintering phase. At least one eye must be visible on each root neck when it is divided.
Tip: If in doubt, the dahlia bulbs can simply be placed in the light and in the warmth for a few days. Then they start to drift slowly.
Conclusion
While cuttings and pre-grown plants are only planted in the bed from mid-May after the ice saints well-formed tubers can already be in the between the end of April and the beginning of May Garden soil. To give the dahlias a head start, it is possible to let them grow indoors or in the greenhouse from the end of February. Planting dahlias in the cold frame is recommended from the end of March, provided that there are no permanent frosts in the double-digit minus range.
