Dahlia Perch Hill

How do you plant dahlias correctly?

Planting time:

Dahlia tubers are planted from the beginning of May, when no more night frosts are expected.

Location:

Any normal, nutrient-rich, and well-drained soil in a sunny location is suitable for planting. The sunnier the Mexican dahlias are, the better; planting them under trees is therefore not recommended. They will also thrive in partial shade, but not quite as lushly. Since dahlias don't tolerate waterlogging, clay soils should be enriched with a little sand. This allows for better drainage.

Planting depth:

The planting depth depends on the tuber size; 15 centimeters, or at most a spade's depth, is ideal. The sprouting points at the base of the root collar should be covered with about 3 to 5 centimeters of soil. The tubers are placed loosely in the planting hole.

Planting distance:

The planting distance between tubers or neighboring plants depends on the height of the dahlias. As a rule of thumb, the plants should be half as wide as they are tall.

• 80 to 100 cm for tall varieties up to a maximum of approx. 180 cm
• 60 to 70 cm for medium-height dahlias up to 120 cm high
• 30 to 40 cm for low bed dahlias

Flowering time:

Depending on the species and variety, dahlias bloom from July until the first frost.

Pour:

To prevent rot, do not water the tubers immediately after planting. Water only during dry periods and after the first shoots appear. Generally speaking, dahlias in a bed with normal soil only need to be watered during dry periods. However, in light sandy soils, watering may be necessary every two to three days in summer. In hot summers, dahlias need regular, sufficient water to continue producing new blooms. Stationary drip hoses are ideal, as they reduce fungal infections and reduce the amount of watering required. If you do water with a watering can, always water directly at the soil, never above the leaves.

Care tips:

Dahlias like loose soil, so it's recommended to loosen the soil occasionally with a cultivator or hoe during growth. To encourage the plant to bloom again, dahlias need to be pruned regularly. This means removing dead flowers and seed heads. The plants will then form new buds instead of seeds and bloom until the first frost. If the garden soil is good, fertilization is not necessary. Otherwise, fertilize with a heaped tablespoon of organic fertilizer or a complete mineral fertilizer about 2 to 3 weeks after the shoots appear. This process can be repeated in July, before flowering begins. Stop fertilizing in the fall to allow the tubers to ripen better. Dahlia varieties that grow taller than one meter should be supported and tied with stakes when they reach a height of about 40 centimeters.

In winter:

Dahlias are perennial, but not winter hardy in German climatic conditions. After the first frost, when the above-ground parts have died back, the plants are cut back to about 15 centimeters. The tubers are left in the ground for about another week to ripen. Then, if possible in dry weather, they are carefully dug up with a digging fork. Gently shake off the soil. The tubers are best stored in a frost-free, cool, and dry place, such as a shed or cellar. Temperatures of 4 to 8 degrees Celsius are ideal; if stored too warm, the tubers will dry out. Remember to mark the tubers so you know which variety they are next year.