+ When to plant.
Tulips, daffodils, crocuses and other bulbs that flower in spring, have to be planted in autumn, from mid September until late December.
Dahlias flower in summer and should be planted in the spring. They are not frost-resistant so they usually are planted after 15th of May. After that date frost is very unlikely.
Gladiolus and Anemone de Caen also flower in summer. They can be planted after mid April..
+ How to plant.
For almost all kinds of bulbs a hole is made with a depth of 3 times the height of the bulb. Dahlias are an exception to this rule: make a wide and shallow hole, plant the tuber and make sure that there is a layer of no more that 2 cms of soil on top.
+ Distance between the bulbs.
As a rule there should be a gap as wide as 2-3 bulbs.
The distance between dahlia tubers is 40-50 cms.
+ How to plant bulbs in pots.
Fill two thirds of your pot with potting soil. Then plant the bulbs and fill it up with more potting soil. You may plant one variety in each pot, or mix different bulbs in one pot. In a pot the distance between the bulbs can be as narrow as 1 cm. This gives a rich display of flowers. Keep the soil slightly moist.
If you decide to plant more vatieties in one pot, you can also plant them in layers. Start with a layer of soil, then a layer of tulips, another layer of soil, then daffodils or hyacinths. Cover with another layer of potting soil and then a layer of smaller bulbs like crocuses, grape hyacinths or chionodoxa. This will be enough to enjoy a variety of flowers over a long period.
Please note: spring flowers like tulips, daffoldils or grape hyacinths need a cold period of 8 to 16 weeks before they can flower. After potting, they have to stay outside, but if it is frosty, keep them in a cool shelterd place. After 8-16 weeks you can place them inside the house and enjoy early flowering in your home.
Dahlias can also be potted indoors earlier, and after 15 May they can be planted in the garden or left in a pot outside. Dahlias should be planted no deeper than 2 cm under the surface.
+ What to do when the flowering is over.
If bulb flowers in your garden are out of bloom, just leave them in the ground. Don't cut the green leaves, they keep the bulb alive. When the leaves have dried you may cut them off. Many bulb varieties are perennial. If they are in a good place, they will flower again for many years, especially daffoldils, crocuses, grape hyacinths and our special bulb flowers. Many of them will naturalize. It may also happen that they diminish year after year until nothing is left. The reason for this is often the ground, either too dry or too moist. But on the whole bulb flowers are quite easy to maintain.
Tulips are special chapter. Botanical tulips are perennial. Tall tulips often only live for one season. Exceptions are Queen of the Night and the Impression varieties. They often return year after year.