Over-wintering summer-flowering bulbs

Summer-flowering bulbs often cannot spend the cold season in situ and you must lift them from the ground and plant them again next year. It is the right time to create some space in the flowering beds and borders for winter!

Over-wintering summer-flowering bulbs
Whether large or small flowering, Dahlias are easily kept from year to the next.
Over-wintering summer-flowering bulbs
Cannas end up forming large, impressive stumps.

Keep or replace?

A lot of summer flowering bulbs have already built up their reserves for the following year when the first frosts arrive. Well stored, these bulbs or tubers can be replanted next year. It is the case for Dahlias, Cannas, Begonias, Gladiolus… The rhizomes of Dahlias and Cannas even become more beautiful and bigger as the years go by. They can even be divided after two years. They are all the more so, easily stored, as all they require is a cool room and they do not need any light to patiently wait until the following spring.

For the other summer-flowering bulbs such as Arums and Gloriosa Lilies (or Malabar Lily) keeping them out of the soil is more delicate and it is often better to replace them.

Well stored

The easiest is to wait until the first frosts have blackened the foliage and the stems of the summer-flowering bulbs. The plant has then received the message to enter in its dormant season and there is no risk of the plant wanting to carry on growing after it has been lifted from the soil. As the blossoming season can sometimes be lengthy in some areas, it would be a shame to go without it! You need a cool, frost-free, well- ventilated room. Too much heat and the tubers will dry out. Too much humidity and they could rot. A cellar kept at between12 or 15°C is perfect. They can also be stored in the vegetable compartment in the refrigerator.

Step by step

1 Cut the stems approximately at 10 cm.

Over-wintering summer-flowering bulbs
2 Lift/fork the plant carefully so as not to break out the large roots.
Over-wintering summer-flowering bulbs
3 Shake gently so as to remove excess soil.
Over-wintering summer-flowering bulbs
4 Place on a bed of sand or ashes, in a box.
Over-wintering summer-flowering bulbs
5 Cover up part of their base with dry sand or ashes.
Over-wintering summer-flowering bulbs
6 Store like so in a cellar.

Over-wintering summer-flowering bulbs

The ones that can be left in situ

A few summer-flowering bulbs can be left in the ground, depending on the area and the type of soil. Highly sandy soils, where water never stagnates are more suited to spending all year round in the ground. Small-flowering Dahlias, Italian Gladiolus and Cannas (where the soil does not freeze in deeper than 5cm deep) are amongst the summer-flowering tubers which can spend winter in the garden. Protect the site with a layer of dead leaves, approximately 10cm thick.

M. Jean-Michel GROULT
 
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