Final answer:
The pruning technique to make the canopy of a shrub less dense is thinning-out. Thinning-out selectively removes some branches to improve light and air flow while preserving the plant's natural shape.
Step-by-step explanation:
The pruning technique used to make the canopy of a shrub less dense is thinning-out.
Thinning-out is a pruning technique that involves selectively removing some branches at their point of origin or at a lateral branch. This method is preferred for making the canopy less dense because it improves light penetration and air circulation within the plant without significantly altering its natural shape. Thinning-out helps maintain the health of the shrub by removing weak, diseased, or intersecting branches, which can prevent disease and pest infestations. Unlike hedging, lopping, destemming, or scalping, thinning-out targets individual branches and maintains the integrity and aesthetics of the shrub. Consistent thinning out over time is the most effective approach to ensure that the shrub grows strong and maintains its desired appearance.
To make the canopy of a shrub less dense, the pruning technique that should be used is thinning-out.
Thinning-out involves selectively removing branches from the shrub's canopy to allow more light and air to reach the inner parts of the plant. This helps to reduce the density of the foliage and promotes healthier growth.
By thinning-out the canopy, the shrub will have better air circulation, which can reduce the risk of disease and pest infestations. It also allows more light to reach the lower branches, which encourages their growth and prevents them from becoming weak and leggy.