HERBACEOUS PLANTS

Wairarapa Times-Age, 6 January 1939, Page 9

HERBACEOUS PLANTS

PROPAGATION POSSIBILITIES

Summer may not seem the ideal time in which to propagate herbaceous and rock plants. It would certainly be folly to transplant at this season plants that are just coming into flower, but in the case of those that have already bloomed it is a different matter. Polyanthus and primroses have by this time completed their first growth and are resting for a time before they make fresh leaves and roots. These may be lifted and divided with perfect safety, provided they are replanted at once and without exposing their roots unnecessarily to the sun. They should also be watered thoroughly for the first week after replanting. Not only is this a useful method of increasing stock, but is also of definite value to the plants. Old clumps tend to lose vitality and to become hard and woody at the centre, and unless they are lifted and divided periodically the quality of the flowers is bound to suffer. If possible all dividing should bo done with the fingers alone, a sharpened stick or the knife used only in an emergency. If clumps are pulled apart by hand there is little danger of serious damage being done to the roots, but when tools are used great care must be taken. The mossy Saxifrages, which have been making such a good show, can also be divided now. Large old clumps often turn brown in the centre and die right away especially if they happen to be growing in a sunny, dry place. Timely division will prevent this, and will enable a supply to be kept up of those close, hummocky plants that are such a delight, even when they are not producing flowers. All the subjects so far mentioned will do far better after division, if planted temporarily in a shady border.

For preference, this should be close to a wall or fence with a southerly aspect, and not under trees: but if a border shaded by trees must be used, water the plants thoroughly. Trees fill the soil for an astonishing distance with their roots, and extract most ol the natural moisture from it. A little leafmould worked in will help the plants considerably. If the soil is of a heavy nature, it can be be further improved by digging in some gritty sand. Another plant which may be divided as soon as it has finished floowering is the familiar bearded iris. It is interesting to see how this plant starts to make a fresh set of roots almost before the flowers have faded. This is the signal for the propagator to commence operations, for if the plants are lifted without delay, and carefully divided, they will soon re-establish themselves. These divisions will produce first-class flowers in the following season. The rootstocks or bearded iris are quite different from those of many other herbacious plants. They form thick, creeping rhizomes, which in a

well-established plant lie just on the surface of the soil, and from these the feeding roots are formed. It is a great mistake when planting these iris, to bury the rhizomes too deeply. Though they should not be left on the surface, cover only with sufficient soil to enable them to be firmed up and to keep the foliage erect until new roots take hold of the soil. Later, on partly by a natural lifting on the part of the plant, and party by washing away of the soil, the rhizomes will resume their natural position.