Maintenance of paeoniarockii after flowering is crucial for its recovery and flowering next year. The following are key maintenance points:

1. Timely pruning of residual flowers
   Cutting off residual flowers: Cut off the residual flowers immediately after the flowers fade (keep 1-2 leaves below the pedicel) to avoid seeding and consuming nutrients.
   Keep leaves: Keep healthy leaves for photosynthesis to accumulate energy for root system and flower bud differentiation.
   Autumn thinning: After autumn, cut off diseased and weak branches and overcrowded branches, maintain ventilation and light transmission, and reduce diseases and insect pests.
2. Reasonable nutrient supplementation
   Post-flowering topdressing: Apply phosphorus-potassium compound fertilizer or decomposed organic fertilizer (such as cake fertilizer) once within 1-2 weeks after flowering to promote root system and flower bud development.
   Autumn base fertilizer: Deeply apply decomposed organic fertilizer (such as sheep manure, bone meal) in September-October, mixed with a small amount of phosphorus-potassium fertilizer to enhance wintering ability.
   Pay attention to dilution: Avoid burning roots with concentrated fertilizer, apply thin fertilizer frequently, and water after fertilization to help absorption.
3. Scientific water control and waterlogging prevention
   Watering principles: Keep the soil slightly moist, add water appropriately during drought, and avoid water accumulation and root rot.
   Drainage in rainy season: Clean the drainage ditch when it rains a lot in summer, and raise the planting or add sand to improve the soil in low-lying areas.
   Irrigation before winter: In cold areas in the north, irrigate the soil with “freezing water” before it freezes to improve cold resistance.
4. Disease and pest control
   Disease prevention: Spray carbendazim or mancozeb after flowering to prevent leaf spot and gray mold, and deal with diseased leaves in time after rain.

• Pest control: Spray imidacloprid or matrine when aphids and red spiders are found, and cut off the affected branches and leaves in severe cases.
  Environmental management: Keep the area around the plant clean to avoid accumulation of fallen leaves to breed pathogens.

1. Shade and sun protection in summer
   Moderate shading: Use shade nets to block the strong light at noon during high temperatures in summer, or plant in a position with scattered light on the side.
   -Avoid exposure to the sun: Special attention should be paid to prevent leaf burns in the southern region, but at least 4 hours of sunlight per day should be guaranteed.
2. Soil and root management
   Loosen the soil and ventilate: After flowering, lightly loosen the topsoil (avoid root damage) to enhance air permeability and suppress weeds.
   Improve soil: Heavy clay soil can be mixed with river sand and leaf humus, and organic matter should be added every autumn to keep it loose.

Precautions
Avoid pruning too many branches and leaves immediately after flowering, which will affect nutrient accumulation.
It is recommended to change the pot after the purple peony in the pot blooms, add new soil and prune the aging root system.
Through the above maintenance, the purple peony can effectively restore its growth, promote flower bud differentiation, and lay the foundation for more colorful flowers next year.