One of the prime benefits of pruning outdoor plants is that insects and pests are better managed. A wide variety of pests, worms and insects live and build nests on the plants around your home. Most of these organisms eat the foliage, while others suck sap from surrounding plants. As they feed, these pests weaken the plants, spread diseases and may even eventually kill these plants that you’ve spent so much of your free time on. Some of these animals may also crawl or fly into your house and become pesky uninvited guests. Pruning offers an excellent means for controlling them.
UK’s University of York and Canada’s University of Calgary published a report in 2009 that explains how pruning encourages plant growth. The report was based on studies in molecular genetics and computational modeling. Findings from the report indicate that the different shoot tips on a plant influence the growth of each other. This way, the main growing shoot tends to inhibit the growth of the other shoots. Therefore, when the main shoot is pruned, the growth of the other shoots is encouraged.
Pruning reduces the amount of wood on a plant, making more energy available for the development of large, healthy flowers. When pruning is timed correctly, the practice will increase the number of young shoots that grow to bear flowers. Some shrubs have stems that are beautifully colored. The best and most intense colors appear on young stems. Pruning encourages the growth of such young stems.
SOURCE: ABC Home and Commercial