How to Prune Rieger Begonia After Blooming
As a highly ornamental flowering plant, the management of Rieger begonia during the full bloom period is particularly crucial. When the brilliant flowers gradually fade, scientific pruning not only promotes secondary flowering but also reshapes the plant. Mastering the correct timing and method of pruning, along with subsequent care measures, can keep your Rieger begonia vigorous.
Ⅰ. Core Steps for Post-Blooming Pruning
1.1 Precise Pruning of Withered Flowers
Rieger begonia can bloom for up to 20 days per flower, but the collective flowering consumes a lot of nutrients. It is recommended to start pruning when 80% of the flowers show signs of wilting, cutting diagonally at a 45-degree angle from the base of the flower stem up to the second node, leaving a 1-2mm stub to avoid damaging new buds. If there are some open flowers on the same flowering branch, remove the withered petals first and then handle the entire branch after it has completely wilted.
1.2 Comprehensive Branch Pruning
After clearing the withered flowers, a comprehensive pruning of the branches is necessary: first, cut off the withered old leaves and woody stems, then thin out the crossing branches in the center, and retain the robust branches growing outward. For new shoot branches, keep 3-4 nodes and cut them short to promote lateral bud differentiation. Special attention should be given to retaining a main stem of 5-7cm at the base, as this is the key area for new flower bud germination.
Ⅱ. Solutions for Special Conditions
2.1 Treatment of Diseased Branches
If black rot is found on branches, immediately cut down 2 nodes and apply carbendazim powder to the cut. For branches infected with gray mold, it is recommended to use alcohol flame to quickly burn the cut, which can both disinfect and promote the formation of healing tissue.
2.2 Techniques for Shaping Pruning
To create a full plant shape, a reduction pruning method can be used: retain 1/3 of the length of the branches sticking out of the canopy, and combine with pinching to promote branching. For hanging varieties, focus on retaining the pendant branches, with each branch keeping 5-7 functional leaves to ensure the efficiency of photosynthesis.
Ⅲ. Key Points of Care After Pruning
After pruning, stop watering for 2 days to promote wound healing, then gradually resume watering. It is recommended to use a phosphorus-potassium liquid fertilizer (N-P-K=5-15-30) for topdressing, applied once every 10 days. Maintain an ambient temperature of 18-25°C, combined with 4 hours of scattered light exposure per day, and new buds can be seen in about 30 days. Healthy branches pruned can be used for propagation with vermiculite, achieving plant renewal.
Through systematic pruning management, Rieger begonia can quickly recover and also achieve annual flowering through flower bud differentiation control. Regularly observe the plant's condition, combined with water and fertilizer management, can keep this 'four-season begonia' continuously blooming with charming charm.