Summer pruning apples and pears allows sunlight to ripen the fruit and ensures good cropping the following year. For instance, you may want to prune azalea or forsythia plants. Ideally, prune before the new leaf buds open, so that energy is directed into the remaining stems. This is the main method of pruning for restricted … Pruning Bougainvillea in Summer: I’ve gotten comments like “why is my bougainvillea not blooming” or “my bougainvillea was blooming was blooming when I brought it home but now it’s not”. Pruning these plants in the summer allows you to control their size and/or improve their structure, while still allowing ample time through the end of the season for the plant to form flower buds that will bloom next year. Summer is a good time to prune plants that flowered early in the spring. There are multiple answers for both (the most fundamental is that bougainvilleas need full sun and warm temperatures to flower successfully) but there are only 2 reasons I want to address in this post. The main aim of pruning evergreens is to maintain their shape, control their growth and remove any frost-damaged stems. Discover eight reasons to prune in summer..