The Reasons for the Yellowing and Falling of海棠 Flower Leaves
As a traditional famous flower in China,海棠 flowers are deeply loved by horticulture enthusiasts for their brilliant blooms and elegant tree posture. However, when the leaves turn yellow and fall off, it not only affects the ornamental value but also indicates that the plant's health is in danger. This article will analyze the causes of yellowing leaves of海棠 from four core dimensions and provide systematic solutions.
I. Imbalance in Soil Environment
The Dangers of Imbalanced pH Levels
海棠 is a typical acid-loving plant (pH 5.5-6.5), and long-term use of tap water for irrigation can lead to calcium deposits in the soil, causing alkalization (pH > 7.0). Laboratory data shows that when the soil pH exceeds 6.8, the absorption rate of iron decreases by 60%, directly leading to leaf yellowing.
Scientific Soil Improvement Methods
It is recommended to test the soil pH with pH test paper every quarter, and when alkalization is detected, use sulfur powder (50g per square meter) or decomposed pine needle soil (30% proportion) for improvement. For potted plants, it is suggested to use a formula matrix of「peat soil: decomposed leaf soil: perlite = 5:3:2」to ensure good aeration and acidity retention.
II. Misunderstandings in Water Management
The Golden Rule of Dry-Wet Cycle
Adopt the principle of「watering when dry and wetting when seen\": Maintain soil moisture at 40-60% in summer and reduce it to 20-30% in winter. Use the bamboo stake method to determine, and water thoroughly when the top 2cm of the soil is dry. Special attention should be paid to the fact that terracotta pots lose water faster than plastic pots by 0%, and the watering frequency needs to be adjusted.
Optimization of Drainage System
Place a 3cm layer of ceramsite at the bottom of the flower pot as a drainage layer, and mix coarse river sand to enhance the permeability of the matrix. In case of continuous rainy weather,倾斜 the pot body at a 15-degree angle to accelerate drainage and prevent waterlogging and root rot.
III. Nutrient Supply Plan
Golden Formula for Fertilizer Ratio
Apply fertilizer monthly at the ratio of N-P-K=18-6-12 during the growing period, and switch to high-phosphorus and potassium fertilizer (N-P-K=5-15-10) during the budding period. Always remember the principle of「applying thin and frequent fertilizer\", dilute the standard concentration to 50% for use. Organic fertilizer, such as fermented sheep manure, is recommended, with 100g added to each pot to maintain a 3-month fertilizer effect.
Supplementation of Trace Elements
Apply chelated iron (Fe-EDTA) 1000-fold solution to the leaves every quarter, and use it in combination with magnesium (magnesium sulfate 500-fold solution) to effectively prevent yellowing leaves due to nutrient deficiencies.
IV. Light Control Strategies
Dynamic Management of Light Intensity
Ensure 6 hours of direct sunlight in spring and autumn, and use a shading net (40% shading rate) from 10:00 to 15:00 in summer. For north-facing balconies, use supplemental lights for 2 hours daily (light intensity 2000-3000lux). Regularly rotate the pot to ensure even light exposure from all directions and prevent biased growth.
By systematically controlling the four elements of soil, water, nutrients, and light, and combined with regular pest and disease control (focusing on the prevention and treatment of red spiders and (T-J) disease),海棠 flowers can regain their lush green leaves. It is recommended to record the growth status monthly and establish a personalized maintenance file to prevent yellowing leaves in advance.