How to Prepare Daylilies and Irises for the Winter

In Daylilies and Irises by Christine Moore

Bearded Iris hybrids growing in my garden

Autumn is one of the most looked forward to season by any keen daylily or Iris gardener. This is the time when the drooping and faded daylilies and bearded Irises will have another flush of flowers. They may even re-bloom if they do they will be the centre of attraction in any garden. Given that while gardening in autumn is also the time to think of the harsh winter season ahead as daylilies and bearded Irises have the tendency to go dormant during heavy winters in Australia. People living under these circumstances will have to prep up these plants in the autumn so that they get ready for the forthcoming spring.

Before frost sets in

There would be dead and brown leaves on the daylilies and around your bearded iris. Undoubtedly an annual task is to tidy up the plants as needed.

  • Remember to sanitise garden tools before cutting each different daylily clump.
  • Trim the daylilies about 20 cm high so you can see to get into the clumps and pull off the old leaves before the first frost.
  • This time of year, the old flowers and brown stems should come off clean at the base of the rhizome and crowns on both different varieties.
  • Any flower that looks like it is going to fall or has turned brown in colour also needs to be cut off at the leaf level to prevent seeds.
  • Removal of the yellow and browned off leaves will need to be picked up to prevent diseases.
  • Keep your eye out for aphids they are white on daylilies and grey on bearded iris. If you see them, they need to be sprayed with white oil.

Well kept Irises and daylilies will help in protecting the roots and rhizomes from rotting during the winter. This way you can be sure of seeing the new buds during spring time.

The area around the daylilies and Iris needs to be kept cleaned and cleared. This will prevent the slugs and snails, millipedes and slaters to find rest places in the soil and around the plants. These bad news bugs and molluscs can affect the development of roots and rhizomes and buds on the plants even in the winter when they are dormant.

Winter Dormant and Semi Evergreen 

With my experience in cold climates daylilies and bearded iris go dormant, whether they are classed as dormant or deciduous losing all their foliage or if they are classed as evergreen. It is too cold for the daylilies and irises to grow this time of year they lose their ability and urgency to grow and flower. Winter in Australia gives the daylilies that well earned rest in cold climates even though evergreen daylilies still maintain all their leaves they remain dormant. Plants that lose their leaves should all be called deciduous but for some reason, this is not the case with daylilies.

However, in warmer climates daylilies have that extra growing period over cold climates where the daylily and bearded iris continues to grow during their warm winter months but the down side is that bearded iris may not bloom.

Bearded iris while dormant naturally has shorter leaves in the winter months.


Doing a little bit of smart gardening just before the winter sets in will help in keeping the daylilies healthy during the extreme winters. Daylilies and irises have great resistance power and with a little bit of care will be able to survive the cold winter months easily.


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