Is ignorance bliss? Knowing why and when to prune
Plants produce flowers which is the first step in the production of seeds or fruits; the future progress of a plant’s growth is dictated by how it is pruned, which is aided by the knowledge of why and when to prune.
The exercise of regular, unnecessary pruning negates the production of the process. Pruning removes potential flower production which follows that there will be no seed or fruit. Is ignorance bliss………..?
Pruning is carried out for several reasons: to remove dead or diseased wood; control shape and thus future growth to enable ongoing pruning; to remove weak or crossing branches thus keeping a balanced branch system. The latter is especially important in encouraging “outward” growth of branches whilst allowing light infiltration to the centre of the plant which encourages new growth from this area.
When transplanting, pruning of the young, soft growth will assist in a quicker establishment of the plant’s growth. Old, neglected plants can often be rejuvenated by careful pruning resulting in an attractive addition to the garden.
Growth rates in Bermuda are usually constant; with oleanders, for example, it is rapid, especially after pruning. Older, thicker-stemmed oleander branches should be pruned back; where numerous branches need to be pruned, do so in a tiered effect. The pruned cut will then develop new growth at various heights, creating a green face to plant and, not as often seen, a crew cut atop bare branches.
This approach can be used on many shrub types, removing the older growth opens up the centre of the plant which encourages more light and thereafter, new growth.
Pruning is often dictated by the design of the planting being overly heavy with not enough growing space between plants, thus necessitating the need to prune!
Allowing foundation planting to fill in naturally creates a healthier plant with a more natural appearance. Timing for pruning is important as it is best carried out during the growing season. I suggest pruning, at most, three times during the year: late March, to remove wind-damaged growth, and August – especially if has been a wet summer creating much growth as this reduces the impact by wind. Prune to allow a filtering of the wind through the branch system which reduces damage, especially as this is the hurricane season. A further pruning can be done in late October to generally clean up growth for the winter months.
The “how to prune” is a major component for success. Pruning tools include secateurs, loppers, pruning saws, and chainsaws for larger pruning needs.
Small branches not thicker than a pencil should be cut with secateurs. If branches are too thick and the cut is not clean the result is a snagged end which can be a problem if not given a clean cut. Loppers can be used on thicker material and chainsaws – various size blades – on trees.
When dealing with the pruning of mature trees it is recommended that such work be carried out by a tree surgeon, especially if large branches require removal.
The parts of a tree/plant are many. Roots anchor the plant and, on occasion, may require pruning. Terminal buds are located at the growing point; if damaged, lateral buds will grow to replace them.
Branches are shoots that originate from a main axis. A stub is a branch cut back incorrectly and can be a future problem for the plant if not removed. A leader is the growing point of the main stem; avoid double leaders as these will weaken the plant and can cause splitting.
Always prune to an outward pointing bud as that creates a natural growth. An inward pointing bud will invariably create a situation of crossing branches and rubbing of bark, which is not good practice. Make a slanting cut with the slant being opposite the potential new growth – the bud. This protects the bud from becoming overly wet from water running down the stem. Always ensure the finished cut is clean and if need be, clean the edges with a sharp pruning knife or similar.
To create an all-round natural shape to the plant, use the tier-pruning approach which will create growth at all levels and has the potential of producing a wider coverage of flower, seed and fruit. Branching out stems from staying a cut above the rest – which shows in the long term!
Malcolm Griffiths is a trained horticulturalist and fellow of the Chartered Institute of Horticulture in the UK. He is also past president of the Bermuda Horticultural Society, Bermuda Orchid Society and the Bermuda Botanical Society