Post category: Border Perennial Flowers
Border perennial flowers are used in mixed plantings with shrubs, or on their own in herbaceous borders. Traditionally, the non-woody border perennials were restricted to the herbaceous border, which can be a stunning feature, but demands a lot of attention.
A mixed border of herbaceous perennials and shrubs has several advantages. Its shrub content needs little attention, and provides interest in winter, when the border perennials have died down. The border perennials provide colour and lush foliage in summer to soften the harsher outline of the woody plants. The shrubs provide valuable shelter, and shade in some cases, for the herbaceous perennials that fill in around, between and underneath them. In large gardens, where there is plenty space, island beds of border perennials and shrubs can be planted. Perennial flowers can be used as temporary filler plants until shrubs take up the space. Many border perennials provide good cut flowers.
Border perennials can be raised from seed sown in trays indoors in April, or in seed-beds outdoors in May or June for some kinds. Time and method of sowing varies but the seed-packets give good instructions.
Lift and transplant the seedlings into nursery beds at 30 centimetres apart. Grow them on until they are large enough for planting into their permanent positions, usually on autumn. Raising plants from seed is a cheap way to acquire a stock of border perennials.
Geranium x magnificum
Alternatively, plants can be purchased, or divisions exchanged. Division, by pulling the crowns apart, or by cutting with a spade, is the main method of plant raising. Plants can be divided at any time during the dormant season, but the usual months are October/November and March/April.
Plant border perennials in good, well prepared soil with no perennial weeds. Dig over the site and work in plenty of well-rotted manure, compost, straw or peat. About 100 grams of general fertiliser per square metre should be applied. The site should be sunny for most types, and the soil moist but well-drained. Some types, however, enjoy damp conditions; some like shade, and a choice can be made for hot, dry, conditions too.
Planting time is October/November or March/April, when the soil is moist but not wet. Place the crowns a couple of centimetres deeper than they were before lifting. Plant in uneven-numbered groups for best informal effect.
Aftercare for perennial flowers
Hoe around the plants in spring, to prevent weeds becoming established. Mulches of well-rotted manure or compost help to feed the plants and conserve moisture, but some kinds of mulch can bring weed problems too. Dig out perennial weeds, or paint on Tumbleweed or Roundup when they appear.
As the plants grow, some types need to be staked. Place a few sticks or canes close to the plant and run twine around and through the clump of shoots for support. Put support in place in time to prevent plants flopping around. Some plants will need watering when young, and in a dry summer. Watch for signs of drought, then water heavily.
An attractive combination of blue, pink and yellow
When the flowers fade, the plants begin to die back for winter. By October, most of the nutrients in the flower stalk and foliage will have been re-absorbed by the plant. Leave on the withered flower stems and seed heads – these can be very decorative during winter. As the tops become untidy, they can be cut away and the area tidied up. Every few years, the more vigorous plants will have to be lifted, divided and re-planted to keep them to a reasonable size.