What to know about Dahlias
Dahlia is a large plant group originating from Mexico. Dahlia can be divided into several different subgroups, most often characterized by flower shape, flower size, and height. More on this in the following sections, but first, we'll provide some general care instructions for dahlias.
When should the tubers be planted?
Dahlia tubers should be planted in the spring when the soil temperature is 8-10 degrees Celsius. Make sure the risk of night frost has passed. This could, for example, be after May 1st, depending on the weather. Plant your dahlias no later than Midsummer's Eve, allowing them still to grow 1 meter and produce flowers for bouquets in August, September, and October.
The soil you plant your dahlias in should be good, nutrient-rich garden soil. Plant the tubers 10-20 cm deep. You can plant your dahlias both in pots and in beds.
Care and Fertilization
When planting, add 30-40 g of fertilizer, e.g., 'Garden Fertilizer No. 1'. After this, add 10-20g per square meter 2-3 times with a month's interval. This will result in beautiful plants.
Snails...
Dahlias are very beautiful. But we are not the only ones who love dahlias. Snails do too. Snails can be kept away with ferric phosphate, slug traps, or copper tape.
Flowering
Dahlias typically bloom from July until the first frost arrives.
Dig up and store
Before the first frost in autumn, dig up your dahlia tubers. The tubers should be overwintered in a frost-free and dry place.
Dinnerplate, Giant, and Large-flowered
This group consists of dahlias with flower heads 25 cm or larger, while the large-flowered dahlias have flower heads of 20-25 cm.
This group is suitable for bouquets, and the more flowers you pick, the more flowers will appear. They bloom from July and can, in good years with mild and dry weather, continue to bloom into October.
This group of dahlias grows quickly, and if you pinch off the top shoots at 15-20 cm and again at 35-40 cm, you will get a bushier dahlia. These dahlias typically reach a height of 80-120 cm.
Medium-sized and Small-flowered Decorative
This group consists of all classic, double dahlias with medium-sized (15-19 cm) and small (under 15 cm) flower heads.
This group is suitable for bouquets, and here too, the more you pick, the more flowers your dahlia plants will produce.
These dahlias bloom from July and, in good years without early frost and with a dry autumn, can bloom into October.
The plants grow quickly, and if you pinch off the top shoots at 15-20 cm and again at 35-40 cm, you will get a bushier plant.
These dahlias will reach a height of 80-120 cm.
Ball and Pompon
This group consists of dahlias that all have spherical flower heads, hence the names 'Ball' and 'Pompon'.
Ball types have a flower size of 7-12 cm, and pompon types have a flower size of 4-5 cm. These dahlias have a plant height of 80-120 cm, which depends on the individual variety.
These are well-suited for colourful bouquets. Again, the more flowers you pick, the more flowers will appear.
To get a bushier plant, pinch out the top shoots at 15-20 cm and again at 35-40 cm. This results in a bushier plant with more flowers.
The Low
This group of dahlias consists of those dahlias that have a height of 30-70 cm. All of these dahlias are good for pots, containers, and planting in the foreground of beds.
The flowers vary from decorative to cactus-flowering and single-flowered, top mix. The size of the flowers is 6-20 cm. However, there may be varieties with larger heads of 25 cm, including low-growing Dinnerplate hybrids.
If you pinch off the top shoots of the plant 1-2 times during the early growth period, you will get a plant with a more bushy growth.
Bee, Insect & Butterfly Friendly
This group of dahlias share the characteristic of having single flowers that offer pollen and nectar to bees, butterflies, and other insects. In this group, you will find anemone-flowered, collarette dahlias, peony-flowered, Honka, orchid-flowered, mignon, and the 'wild' tree dahlia called Dahlia imperialis.
With such insect-friendly dahlias, you can facilitate an increase in insect life in your garden.
Dare to mix?
Dahlias are a fantastic group of flowers that provide lavish blooms year after year. They do need to be dug up, but the effort is well worth it. Go wild with dahlias and create colourful beds.