Final answer:
Plants that flower in the spring should be pruned just after flowering to allow healthy recovery and to prepare for the next growth cycle, avoiding any negative impact on future blooms.
Step-by-step explanation:
If a plant flowers in the spring, it should typically be pruned just after flowering. Pruning just after flowering allows the plant to recover and prepare for the next cycle without affecting the next year's blooms. Pruning at this time also helps to maintain the health of the plant by removing any spent flowers or dead growth, which can help to minimize the risk of disease and pest infestation.
This is in contrast to late summer, which can be too close to the winter dormancy period and could potentially harm the plant if new growth is encouraged too late in the season. Pruning after the cold of winter, but before new growth is generally a recommendation for plants that bloom later in the year or for non-flowering pruning needs to shape or manage growth.
Understanding the life cycle of a plant, including when tubers are planted and harvested, as well as recognizing the effects of photo-period on flowering such as through experiments with controlled light conditions, helps in making informed decisions about when to prune.