Perennials

Perennials are plants that last more than a year. Bulbs and fruit are perennials, but I consider those on their own pages. Most of my flowers are perennials, and these are discused below.

Perennials have to survive the winter and are therefore, if you're sensible, hardy. If you have a tender or half-hardy perennial, then the frost will kill it, unless you protect it in some kind of way or even remove the plant to a frost-free place. I don't do this type of gardening! You can treat perennials as annuals, and replace them each year, if you want.

Perennials start as seeds. They grow and form a smallish plant in the first year. In fact they may not even flower in their first year. Then rather disconcertingly, they may die back in the autumn. They are not dead - they are deciduous, but unlike trees, even the stems may die back to ther ground. They certainly look dead! But don't dig them up. Cut the dead stems off and wait for spring, when new shoots grow again.

The plant gets bigger in two ways. The actual plant may get taller, or have more flowers. Plus it may produce more plants to form a clump (or some some cases a line). This tendency of perenniel plants to get bigger is certainly a good thing, but you may feel that a plant is too big. You can always cut off bits round the edge and throw them away. But if these edge parts have their own roots (which often happens) then you can replant these elsewhere, and increase your plant stock! These edge parts are often more vigorous than the central bit, which can even die off, sometimes. Or you can give them away to friends, etc. There may be a large central root ball with lots of stems, which you can divide in two using a spade. Or there may be just one central stem and all the roots come from this, and then you can't get new plants from it. These different behaviours depend of the type of plant, and you will no doubt learn what you can, or cannot, propagate.

If you take over a garden, and something is growing which dies back in the autumn, is is a dead annual, or is it a perennial? First, try snapping off a bit of stem. If it bends, then it's not dead, so leave it. But if it does snap, then that part is dead, but the whole plant may not be. I suggest cutting it off at ground level (if everything above ground is dead). If it's a perennial, this will encourage it to regrow next spring. If it was an annual after all, then the root that you've left below ground has died, and will gradually rot away, providing a small amount of instant compost to your garden!

Some perennials are ever-green, and so don't die back, and the leaves stay on all winter. At least you know that they're alive! Others drop their leaves, but the stems stay alive, and these shouldn't be cut back to the ground (although you may want to prune them in other ways).

The diagram above shows that perennials are grown from seed. They are, of course, but you don't need to! Mostly perennials are sold in pots as plants. See Planting out for more information on this.

You can grow perennials from seed. Growing perennials from seed isn't common, as you end up with a lot of plants that you don't need! And they may not work, or may die or get eaten when planted out. However, there is more choice in seeds than in plants, and there is a certain satisfaction to doing it. And you can give away the spare plants to other people.