A true herbaceous border or bed is supposed only to contain herbaceous perennials, but a way round winter bareness is to plant strategically placed patches of spring bulbs throughout the area. These clumps can then be removed for the summer, and the spaces filled with summer bulbs (say gladioli), dahlias, or properly chosen bedding plants.
However, many plots just cannot afford the space for such a scheme, nor their owners the time for maintenance, but herbaceous perennials still have a purpose in a modern garden as the colours and flowers they supply are so totally different from those provided by trees and shrubs. One solution to the problem of trying to get a quart into a pint pot is the mixed border, where annuals, bulbs, shrubs, conifers, roses and herbaceous perennials all have a contribution to make. It is fairly important to spend some time planning such a bed or border properly or it can look unbalanced or bitty, but it can also be a very interesting feature if you get it right. If you are not keen on mixing everything up you can achieve some segregation by keeping the shrubs to the back (or centre in an island bed), and planting the perennials, and annuals if you want them, together towards the front.
If you want only a few perennials for additional summer interest, you can leave odd spaces for them in what would otherwise be an all-shrub border. When they are cut down in winter you hardly notice it, but make sure you position the clumps properly, or the effect can be rather gappy.
Similarly, if you still fancy the idea of a true herbaceous border but you are not keen on its aspect in winter, you can plant at regular intervals just a few shrubs which do not get too big and provide winter flower or foliate interest. These have to be chosen carefully for suitability — many of the winter-and spring-flowering viburnums are fine, also the daphnes and the witch hazels for flower (and a bonus of scent), whereas variegated evergreens such as some hollies, elaeagnus and photinia would provide leaf effects. If you are a real pedant and you want nothing but herbaceous plants in the bed or border, you could liven it up with evergreen perennials evenly distributed throughout the planting. Some suggestions for these are given at the end of this section.
To summarize therefore, the advantages of herbaceous perennials are that they can provide flowers and colour for both garden decoration and flower arrangement; they come up every year and do not have to be removed and replaced annually, and many of them attract wild life – mainly bees and butterflies — to the garden. The disadvantages are that they must be chosen carefully to make sure you have not landed yourself with the most awful rubbish; many of them require staking and tying during the growing and flowering season; they usually need dead-heading to ensure a subsequent flush of flowers; they have to be cut down at the end of the season; many of them only have one flowering period (e.g., irises and oriental poppies) so are not contributing much to the overall design for a large part of the year, and every three or four years, or when the clumps begin to look played out, they need to be dug up, split, and the newest growth replanted.