HERBACEOUS AND BORDER PLANTS
The garden border has evolved over many years as the place around the house to grow herbs for culinary use, flowers to cut for the home and grow a few colourful favourite plants. Plant explorers brought back new plants to try out and slowly the variety of border plants increased in range. These can include shrubs, roses, herbaceous plants, bulbs, climbers, ground cover, and anything else that happens to be popular at the time. Often in the early years before plants get established any bare patches can be filled with bedding plants and annuals from seed sown each year.
Borders next to buildings are often designed to link the hard building structure into a soft landscape, but with minimal maintenance in mind. Evergreen ground cover including conifers, are favourite and if the ground is on a slope choose plants that can bind the soil surface to prevent erosion such as flag Iris and Shasta daisies.
Borders are usually long and narrow to be viewed from the front with a solid and usually permanent backing. This may be the house wall, a fence or hedge. Although it is natural to have the taller plants at the rear and short ones at the front, try to vary this to give variety of height.
Each plant will have its own season from the Doronicums and Pulmonaria flowering in early April, Delphiniums in mid summer, to the Michaelmas Daisies in September and October. It is better to try and group plants together in their season to increase the impact, and choose plants that blend well together by height, variety of foliage shape or colour. Good combinations include flag Iris with Oriental Poppies and Pyrethrum, try day lilies with Lavender in adjacent drifts, Delphiniums and Phlox are excellent together for height and colour and at the end of the summer into autumn try Anemone Honorine Jobert with a range of Asters, (Michaelmas daisies). At ground cover height, the black grass Ophiopogon is dense enough to smother weeds and when underplanted with white snowdrops is the perfect combination for late winter.
Where ever a plant is a late starter, under plant it with early flowering bulbs such as snowdrops or crocus. Plants that have a very short season such as Pulmonaria can be mixed with Cyclamen hederifolium which begins to grow and flower in late summer and then retains its foliage all winter.
If the border is in shade or partial shade select appropriate plants such as colombines, (Aquilegia), Hostas, Trilliums, Meconopsis, Epimedium, and Primulas, Bergenia, Lamium and Persicaria for ground cover.
If the border is free standing and is not backed by a building, a hedge at the back can help to define its shape, give shelter from strong winds, add colour and give a green background to the plants when in flower.
If the back of the border is a wall or fence it could create an ideal spot for a climber to give added height.
Soil preparation and planting
Borders are often planted up in the autumn so ground preparation is normal in late summer. If the soil needs a lot of amelioration, add a fair bit of garden compost, dig it in then sow a crop of mustard in spring. Dig it in when it comes into flower but before it sets seeds. Allow it about a month before planting so the mustard is beginning to rot down and open up the soil. Make sure the soil is firmed and raked level and water if necessary before planting. Water again after planting.
Order plants well in advance as often the more popular ones sell out quickly. Your local garden centres will stock most of your needs, but it may be necessary to go to specialist growers for the best varieties. Blackmore and Langdon in Bath specialise in Delphiniums, Phlox and Aquilegia, and Claire Austin in Shropshire specialises in hardy plants. She has some terrific varieties of flag Iris, Daylilies and Oriental Poppies. They both have websites.
Most plants display best when planted in bold drifts.
These tend to be lower growing than the majority of herbaceous plants, and may not die down in winter such as border carnations and Pinks, Lavender, Rosemary, Kniphofia, Sedum and Bergenia.
They add interest in the winter months when other herbaceous plants are dormant and have died back to ground level. Many rock garden plants can be added to the front of borders to soften edges such as the Delosperma, a succulent sun loving plant packed with yellow flowers in May and grows quickly, though no higher than three inches.
Flag Iris have always been my favourite. They are so easy to grow and come in some fantastic colours, though you need to buy from the specialists to see a good range. Daylilies also have a wide range of fantastic colours that will brighten up any border.
True herbaceous plants die down in winter, but they can grow very fast and there is always something in flower from April till the frosts come the following winter.
My season starts with the blue Pulmonaria and yellow Doronicums in April, then the Himalayan blue poppies and Euphorbias in late April or early May.
Soon there is a rush as the Peonies, Pyrethrums, flag Iris, Colombines, Campanulas, and Oriental poppies enjoy the warm weather.
As they finish, the summer flowers take centre stage with Phlox, Delphiniums, Daylilies and Geraniums.
Autumn is the time for the Michaelmas daisies, Agapanthus, Kniphofia and Anemone Honorine Jobert. Most of these plants need to be in a large group to have full impact.
Spring flowering snowdrops, aconites and crocus are perfect in any spare space, and even narcissus, tulips and hyacinths can be found a spot. Many drifts of low growing plants will not mind a few summer flowering lilies planted at their feet.
Wherever possible I tend to only grow those plants than can stand up without needing support, but some essential types such as the Delphiniums will require staking. Weeds are usually only a problem early on as once the plants grow they will soon smother out any weeds.
After three or four years some clumps will require dividing and replanting.