Skip to content

Gladioli overwinter and propagate: How to get the flowers healthy through the winter

Gladioli are among the most beautiful exotics in the garden and delight the eye of the amateur gardener in summer and autumn. They also enjoy great popularity as cut flowers and are indispensable in autumn arrangements and bouquets. However, after the end of the flowering period, you need to winter gladioli. In today’s article we will explain how to do this.

Overwinter gladioli outside: Is it possible?

Gladiolus overwintering instructions for autumn and winter

Gladiolus is not a native flower and does not tolerate frost, sub-zero temperatures and strong winds. In regions with mild climate, it can spend the winter outside. It is assigned to winter hardiness zone 9 and can survive temperatures as low as -6° Celsius without damage. However, in Central and Northern Europe, the plant is brought to the winter quarters after the end of the flowering period. If you leave the gladiolus bulbs outside, you risk them freezing.

Overwintering gladioli: this is what you should pay attention to!

Planting gladioli in spring gardening tips

If you overwinter your gladioli, there are a few things you should keep in mind. Only in this way can you be sure that the delicate flower will get through the winter well and will bloom again the next year.

Overwintering gladioli: When should you cut back the flower?

Wintering and storing gladioli in November

Depending on when the bulbs were planted in the garden in the spring, the flowering time of gladiolus can vary greatly. By the end of September at the latest, all the flowers wither. Therefore, in October and November, you can cut back the flower close to the ground. When doing so, cut off all above-ground parts of the plant. If it does not rain for 3-4 days and the soil is dry – then you can also dig up the bulbs.

Wintering gladiolus bulbs: instructions.

Gladioli overwinter and propagate instructions and useful tips

First, very carefully dig up the bulbs. The best way to proceed is as follows: Dig up the gladiolus bulbs along with some soil. Then carefully shake off the soil or carefully remove it with a cotton cloth. Then thoroughly inspect the gladiolus bulbs for diseases and pests. Sort out any damaged bulbs. Then place the gladiolus bulbs in a moving box and let them dry in a cool, sunny place. The best place for this is a winter garden or a greenhouse.

After 4-5 days you can remove the bulb casings and cut off withered roots. Place the bulbs in a cardboard box. It is best to leave some space between the tubers. Then mix some substrate with sand and cover the flowers with it.

Overwinter gladioli: In the cellar, in the greenhouse or in the winter garden?

Gladiolus overwintering instructions in the fall after flowering time

The choice of winter quarters is very important. Gladioli need a dark, cool room to do well through the winter. They do not tolerate temperature fluctuations. If temperatures fall below 5° Celsius, then they can freeze to death. If temperatures rise above 10° Celsius, then the flowers will sprout as early as winter. Room temperature of 8°- 12° Celsius and low humidity are optimal. Suitable winter quarters are:

  • the garage
  • the unheated cellar
  • a dark and cool room (e.g. empty guest room)

Gladioli overwintering tips for amateur gardeners

Unsuitable are:

  • the bright and warm greenhouse
  • the unheated garden house
  • the glazed terrace or balcony

Wintering and propagating gladioli

Gladioli overwinter in egg cartons tips

Autumn is the right time to propagate gladioli. The flower can be propagated not only by bulbs, but also by seeds. However, most amateur gardeners cut off the seed pods in the summer before they open. This prolongs the flowering period. Therefore, propagation in the home garden is usually done by brood bulbs. Proceed as follows:

  • After the end of the flowering period, dig up the bulbs. Shake off the soil and store them in a sunny place for 4-5 days.
  • Most tubers form the so-called brood bulbs during the drying period. These are much smaller than the mother bulb. The brood bulbs take 2 years to fully develop and do not form flowers until the third year.
  • Some bulbs also form daughter bulbs. They are white in color and can still form flowers the next year if well cared for.
  • Sort out the daughter bulbs and the brood bulbs. Store the three types of bulbs in separate moving boxes.
  • Next year, plant the mother bulbs as a group in one flower bed and the daughter and brood bulbs in another flower bed.
  • You can then overwinter the daughter bulbs that formed flowers the first year along with the mother bulbs in the fall.

Planting gladioli

Planting gladioli in spring tips

Since gladioli do not tolerate frost, they should not be planted in the garden until early May. Dig a hole 15 cm deep for each flower and place the bulbs at least 20 cm apart. The choice of location plays a crucial role for gladioli. It should be sunny and protected from the wind, so that the flowers feel comfortable there.