About Perennial Flowers and Planting Perennial Plants
Preparing for Perennial Flowers
The best time for planting perennial flowers is early to mid autumn when theis still warm. Alternatively, plant perennials during spring — container-grown perennial plants are widely available from nurseries in spring and can, in fact, be planted at any time of year during fine weather.
Several weeks before planting make a plan for the bed or border, ensuring that ultimate flower colours and heights of the perennial plants are correctly balanced.
For autumn planting, dig the bed thoroughly in early autumn to give the soil a week or two to settle, adding a bucketful of manure or gardenper sq m/yd. Just before planting, break up any large clods of soil and tread the surface of the bed. Finally, sprinkle a couple of handfuls of general-purpose fertilizer, such as Grow-more, to each sq m/yd and rake it into the top 2.5cm (1in).
Planting Perennial Flowers
Perennial flowers are best planted on a dull day. Begin by marking out the planting area as for. Working from the centre of the bed outwards, lay the perennial plants out one section at a time. Space them evenly, allowing room for the eventual spread of the foliage.
For plants with a small root system, use a trowel to take out circular planting holes; for larger ones, use a spade. The hole should be large enough to take the spread out roots of bare-root plants, or the entire root ball of container-grown plants.
Insert the plant upright and fill in around the roots with fine soil until levelled off. Firm the soil well, with your fingers if the soil is moist and lumpy, or with your heel if it is fairly loose and dry. Make sure that the plant when firmed is no more than 2.5cm (1in) deeper than it was before being dug up.
When planting container-grown perennial plants, check that the root ball is not tight and spirally congested — tease away long roots by hand and spread them out in the planting hole before infilling with soil. Pot-bound perennial plants not treated in this way won’t grow well and may show leaf browning a month or so after planting. If these symptoms do appear, lift the plant, loosen the soil around the roots and replant immediately.
Plant prostrate perennials, such as artemisia and thyme, which are intended for spreading ground-cover, in groups of three or four plants. Bunch the roots and stems together to form one plant and insert them as a clump. This will encourage the stems to grow out in all directions and so produce a very much more even coverage of the soil surface.
After the bed has been planted with your choice of perennial flowers, prick the soil with a fork — using only the tips of the prongs — to aerate trodden areas.
Some autumn-planted perennial flowers will show no signs of growth until well into the following spring. If you have not made a plan showing the position and name of each plant, label them clearly. Use metal or wooden labels and write names in pencil or indelible ink. Special plant labels are available on which the name can be scratched or etched.