What type of soil to use when repotting orchids
Repotting orchids is a crucial step in the care process, as the choice of planting material directly affects root development and flowering quality. This article compares the ecological habits of epiphytic and terrestrial orchids, combined with the characteristics of succulent plant cultivation substrates, to provide orchid enthusiasts with a scientific soil mixing plan.
Analysis of special planting materials for orchid repotting
Key points for preparing epiphytic orchid planting materials
Epiphytic orchid roots require an environment with over 70% humidity. It is recommended to use: 1. Basic framework: Pine bark (particle size 1-2cm) accounts for 40% 2. Moisture-retaining medium: Sphagnum moss/coconut chunks account for 30% 3. Breathable layer: Volcanic stones/ceramsite accounts for 20% 4. Nutrient supplement: Decomposed peanut shells/charcoal accounts for 10%. The planting material needs to be replaced every 2 years to prevent acidification and hardening.
Golden ratio for terrestrial orchid soil mixture
Terrestrial orchids need to balance water retention and drainage: • Decomposed leaf soil: Provides organic matter (40%) • Akadama soil: Adjusts pH value (30%) • Perlite: Enhances breathability (20%) • Bone meal: Supplements phosphorus (10%) A 3cm thick layer of broken bricks should be placed at the bottom of the pot as a water filtration layer.
Feasibility experiment of using succulent soil for orchid cultivation
Comparison of physical properties
Laboratory tests have found that: The porosity of succulent soil is about 45%, while the porosity of special orchid planting materials reaches 65%. The water retention rate of succulent soil is 38%, lower than the 52% of orchid planting materials. It is recommended to add 30% bark to improve the soil for terrestrial orchids.
Chemical composition analysis
The pH value of succulent soil is 6.8-7.2, slightly alkaline, while orchids require a slightly acidic environment with a pH of 5.5-6.5. The pH needs to be adjusted with ferrous sulfate solution before use.
Comparative experiments have found that epiphytic orchids should not use succulent soil at all, while terrestrial orchids can be used for a short period after modification, but long-term cultivation still requires special planting materials. It is recommended that orchid enthusiasts mix the soil scientifically according to the variety characteristics to cultivate robust orchid plants.