I like to leave the seed heads of flowering plants on over winter for two reasons. One, because they are attractive when frosted at a time when there isn’t a great deal of interest to be found in the garden and, two, because birds such as Goldfinches, Greenfinches and Siskins eat the seeds. It saves a bit on buying bird food, it gives us something to marvel at when we see the birds taking the seeds and the birds themselves will benefit from finding them.
Seed pods of Evening Primrose
What I hadn’t known until last autumn, when someone described it to me, is that Goldfinches carefully peel open the seed pods of the biennial Evening Primrose (Oenothera biennis) to find the seeds within. With that in mind, I left all of the old plants to stand over winter and went out regularly to see what was happening. Sure enough, starting at the bottom of the stem, the pods were gradually being teased open by sharp beaks and emptied. A few will have fallen to the ground and some will be found by Dunnocks or Robins. What remains will ensure a supply of plants and seeds in coming years, but not so many that we will have a forest of them.
Other plants in the garden here that have seed heads which attract birds are the purple coneflower, (Echinacea purpurea).
Seed head of Echinacea purpurea or Deam's coneflower
Globe thistle (Echinops ritro), Lavender, Asters, and Verbena bonariensis also provide winter seed for birds. Having recently been given a large clump of Rudbeckia laciniata, which is now divided into three smaller clumps, I am looking forward to seeing which birds their seed heads attract next autumn.
Deam’s coneflower, (Rudbeckia fulgida var. deamii) is another one to try.
Of course, one of the best things about not cutting down all the dead plants in autumn is simply that you don‘t have to go out there and do it. Even better, you‘re doing the birds a big favour. So, leave cutting back those plants till late winter or early spring and enjoy the show.