In what year did Lagerstroemia indica bloom?

Generally, in 3-4 years, the flowers of Lagerstroemia indica grow on the spring shoots that germinated that year. Apply shoot-pulling fertilizer in early March, combined with nitrogen, phosphorus and potassium: apply phosphorus and potassium once from late May to early June to strengthen branches and promote flowers; Apply a flowering fertilizer at the end of July and the beginning of September. The fertilizer is cake fertilizer and water to make the flowers bloom brightly.