Why you Should - or Should Not - Deadhead Flowers on Plants

Moluccella laevis - Irish Bells Winter seedhead display.

Deadheading flowers on plants is done for a variety of reasons. As you would expect, not all plants are deadheaded the same way if at all - nor for the same reasons. For instance deadheading a rose is not the same as deadheading a pansy. There are several basic reasons why you should take the faded flowers off plants, and there are several ways in which to do it according to plant. Some plants are better not deadheaded!

In talking of deadheading plants, we include bedding plants; shrubs; perennials; herbs. Most plants in the garden will benefit from having their dead flowers removed. There are also some valid reasons why some plants should not be deadheaded.

The main reason why deadheading is important, is to prevent the flower from moving into the seed-production phase. Once this starts, the vigour that would otherwise be available for new growth – and new flowers – is diverted into seed production. Removal of the seed-making potential allows more flowers and growth to be produced. In many instances, the plant will produce another crop of flowers in its attempt to produce seeds.

With true annual plants, the production of seed is the ultimate goal in order to continue survival. Without seed production, annuals cannot survive even until the next year, for their purpose is to grow, flower and set seed all in one year which will then ensure their survival from year to year.

Perennials differ in that even if they do not set seed, they will still grow the following year – and many years after. They have inbuilt food reserves in many parts of their plant including the roots, stems and in some instances the foliage. They can survive the winter as hardy evergreens or herbaceous plants - storing food reserves throughout winter dormancy.  

Reasons Why Not to Deadhead Faded Flowers

There are certain plants which should never be deadheaded other than for preventing further self-seeding. Most biennials fall into this group and in particular, Foxgloves or Digitalis to give the proper name.

Foxgloves survive for many years in the same patch by producing seeds which generally fall nearby – generating new plants for flowering the following year. They are not perennial plants as is often thought. The flowering plant dies after flowering in the first growing season. Other self-seeding plants include Alchemilla, Forget-me-not and many more. The list can be followed here.

There are several reasons why you may decide not to deadhead your faded flowers and are happy to see the seeds develop – even at the expense of not having a prolonged flowering period. You may simply decide that it is not a ‘natural’ thing to do.

Flowers can be allowed to run to seed – or set seed – to provide food for wildlife in the winter. Many different birds may be attracted to your garden in the winter months in their search for food. For smaller birds in particular - such as Finches and Tits - the winter seed harvest can be a vital factor in survival. They are certainly a pleasing sight as they sway back and forth on slender stems full of inviting early and mid-winter snacks.

Larger birds such as blackbirds with relish the stripping of your Pyracantha berries – as will wood pigeons. A spectacular display of berries can be gorged in just a few visits!

The collection of seeds is another reason to allow the seeds to set. Many gardeners are happy to save seeds and money, by harvesting and storing the seeds of many different plants to start them into growth again the following spring.  

The growing of ornamental grasses will be almost meaningless for many varieties without the spectacular autumn and winter display of nodding plumes of seedheads.

• Self-seeding Biennial Plants
• Self Sown Seedlings importance
• How to Deadhead flowers on plants