Perennials in the Garden - Advice & Information

What is a Perennial?

Basically, a perennial is a plant that lives for more than two years. If the plant has a natural life cycle of two years, then it is a biennial. If it lives for just one year or less, then it is an annual.

If you buy a plant for your that is labelled as a perennial, and you fail to look after it properly, and it dies after a few months, it is still a perennial. But, it is now a dead perennial!

All manner of plants can be perennials. This includes most shrubs and trees, for they all tend to live for more than two years. However, for the sake of simplicity, we simply call them trees or shrubs. Much easier. But, they are true perennials.

For the garden, perennials normally mean that group of plants which live a few years or so, and popularly include plants such as Lupins, Daisies, Delphiniums, Sedums, Yellow Alyssum and the like. Some perennial plants die down in the winter, and then re-grow the following spring. Others are evergreen and do not die down in the winter. The perennials that die down in the winter are known as 'herbaceous' perennials/plants.

'Herbaceous' simply means that the plant dies down in the winter to grow again next year. It hides from the winter weather - sensible. Annuals that die completely in the winter, and do not re-grow, are not herbaceous. They are dead plants!

Some plants are mistaken for perennials because they seem to grow again each year, when in fact, it is not the same plant, but young seedlings from the mother plants. Plants such as Forget-me-nots live forever it seems - once you have them Wrong! The Forget-me-not (Myosotis) plant only lives for maximum of two years. But, before it dies - right after flowering - it re-seeds itself, with young babies which will turn into flowering plants the following spring. It is a biennial! If you mistake the young seedlings for weeds and hoe them up, then you will soon be without Forget-me-nots.

So, if your garden plant lives for more than two years, and it is not a tree or a shrub, then you can safely assume that it is a Perennial. It may or may not be a 'herbaceous' perennial. But, it is a perennial!

Just to confuse things a little. There is also a group of plants which will only live from year to year if you protect them in the winter. These are called tender or half hardy perennials. Plants that fall into this group include Dahlias. Dahlias are normally dug up in the late autumn after flowering, and dried off in a frost free environment - garage or greenhouse - for the winter. These half hardy or tender perennials will live many years if they are looked after in this way.

Most houseplants are also perennials, but we will not deal with those here. here, we talk about perennials in the garden!