Perennials

Perennials are a must for the mixed border.  While shrubs and small trees provide the structure perennials or herbaceous plants provide colour and seasonal interest.  Perennials, unlike bi-annuals, live for more than two years and often go on for decades.  Perennials were very popular in Victorian times when the herbaceous border was the 'must have' for a beautiful garden.  Although perennials are more labour intensive than shrubs or bulbs they are well worth growing and can very quickly create a 'mature' look in your garden.

Perennials grow quickly and spread fast, so make sure that you leave them plenty of room to spread.  If you find that they are getting too big for the space you have planned for them they can be dug up, divided and replanted.  This way you get two or more plants for the price of one, which is welcome as these days gardening is not a cheap hobby and a trip to the local garden centre or nursery can releave you of quite a large sum.

When planning perennial planting for your mixed border you are spoiled for choice.  For a dramatic look and instant height you could plant some of the tall delphiniums that will create an instant impact.  They come in white, cream and all shades of blue and purple as well as pink, the 'Camelot' series is particularly stunning, including the very dark blue King Arthur and light blue Guinevere.  Make sure you stake your delphiniums as they can be blown over or snapped off by strong winds.

Another dramatic plant for the border is the Bearded Iris which comes in a range of colours and looks very elegant.  Papaver orientale (poppies) create a more informal, cottage garden look and provide real splashes of colour.  Again you should support them as their heads can get quite heavy.  Among the slightly smaller perennials you might want to try Penstemons which come in a variety of colours and bloom from mid-summer right into the autumn.  They are easy to grow and maintain, and will keep flowering as long as you keep cutting of the dead flowers.

If you want to create a slightly informal or cottage garden look the one perennial you should plant is Verbena bonariensis.  It has plenty of stiff, upright branching stems which end in small heads of purple flowers and it blooms throughout the summer and into the autumn.  This plant is very attractive to butterflies and other insects.  It can thrive on poor soil but is does like a sunny border.  It does not like prolonged periods of freezing temperatures, especially when the soil is wet. 

When it comes to perennials the sedums are definitely a favourite in most gardens.  With their large heads of pink to red flowers they are the crowning glory of the autumn border.  You should leave dead stems in place until they become soggy and then remove them.  Sedum Autumn Joy and Sedum spectablile are among the best and most popular.