Pinching Plants for Growth, Stopping and Deadheading
Pinching Plants, Stopping and Deadheading
Left to their own devices, the majority of soft-stemmed plants — annuals, biennials, bulbs, corms, tubers and perennials — will develop a reasonable shape with a good display of flowers. Woody plants, on the other hand, invariably need at least some routinein order to produce and maintain an attractive shape and to retain vigour for subsequent growth.
However, all plants traditionally grown for exhibition — such as, dahlias and carnations — and many others besides, produce much better or larger individual flowers or heads of flowers if the growth of shoots and buds is controlled carefully from an early stage. Many foliage plants make a better and more pleasing shape when shoot growth is modified.
Stopping is the process of removing or pinching out the growing tip of a plant to encourage the formation of breaks — side-shoots — and control the flowering habit. Chrysanthemums and carnations are commonly treated in this way, both under glass and for garden cultivation. Some side-shoots may require further stopping at a later date — known as second stopping.
When planting small, young plants into their final growing site — annuals and biennials, in particular — any which are not developing the required bushy shape naturally should be encouraged to do so by pinching out the growing tip from the main stem. However, some species, such as foxgloves and hollyhocks, only ever produce one main stem and no stopping is required.
Stopping is especially desirable where young plants have become lanky through poor cultural conditions in the early stages of growth — a seemingly weak, straggly plant can often be prompted to develop a better shape by pinching out the growing tip together with one third or more of the main stem. Don’t be frightened of being harsh with plants in their early stages since they invariably give better results in the long run. The restriction of top growth may also encourage more energy to be put into root growth, so a transplanted specimen will get a hold quicker.
Pinching plants generally produces new, soft side-shoots immediately and these may be more tender and susceptible to damage from cold or wet than the rest of the plant. For this reason, do not stop plants any later than early autumn — the new growths will not have time to harden before the first frost. Plants should have produced several pairs of fully developed leaves before they are stopped. If they have not reached this stage by early autumn, leave pinching out until spring.
Plants bought from a nursery in the spring may already have been stopped — look to see if the growing tip has been pinched out. If they need to be stopped, wait for damp weather in the early morning when stems are full of moisture and so break more easily.
Usually the growing tip will snap out cleanly — hold the stem between finger and thumb at the base of a leaf joint, then, holding just above the joint with the other hand, bend the stem sharply down. If it does not snap, bend the stem to the other side at right angles. If this fails, do not pull at it — instead, cut it cleanly with a sharp knife as close above the joint as possible. It is best to remove the growing tip together with at least one pair of expanded leaves, otherwise breaks may appear only near the top.
Chrysanthemums must be stopped to get good flowers — if allowed to grow naturally, they develop into bush-like plants, with a mass of small flowers. Stopping also brings the flowering season of large-flowered types forward since many varieties, if left to grow naturally, would bloom late and be spoilt by autumn frosts. Spray types usually break naturally and don’t require stopping.
With large-flowered dahlias, plants send up strong centre growths, but make little side growth until the centre shoots develop flower buds. Two or three weeks after planting, pinch out the growing point — usually late spring or early summer. A fortnight later, six or more growing points will be seen developing in the leaf axils. Again remove the uppermost pair of shoots to promote vigorous growth in the lower side-shoots.
These side-shoots will each produce a bud at the tip, with ‘wing’ buds just below it. For large blooms, pinch off the wing buds when they are big enough to be removed without injuring the terminal bud. To promote longer-stemmed side-shoots and encourage growth in the upper part of the, cut off leaves that grow from the main stem a few inches from the ground.
grown outdoors must be stopped after about four good trusses of fruit have set in order to prevent further flowering. If growth continues, the fruit will not swell and ripen before autumn. Using a sharp knife, cut off the growing point two leaves above the top truss.