What are the requirements for the soil for growing orchids
As one of China's four famous flowers, orchids have strict requirements for their growing medium due to their unique growth characteristics. This article will analyze the core elements of orchid soil from a professional perspective and provide a scientific answer to the common question, "Can common soil be used to grow orchids?"
The Four Golden Rules for Orchid Growing Medium
Porosity: The Survival Foundation of fleshy Roots
The unique fleshy roots of orchids need to grow in an environment with an oxygen content of >18%. Experimental data shows that using a matrix of pine bark + volcanic rock (3:1) can increase root growth rate by 40%. It is recommended to replace the matrix every 2 years to ensure a loose structure.
Drainage: The Key Design to Prevent Root Rot
Adopt a layered planting method: place a 3cm layer of ceramic balls as a drainage layer at the bottom, mix planting stones and humus soil (proportion 2:1) in the middle layer, and cover the surface with moss to retain moisture. This structure can increase the speed of accumulated water drainage by 65%, effectively preventing root rot disease.
Durable Fertilizer Efficiency: Slow-release Nutrition System
It is recommended to add 5% sheep manure organic fertilizer as a base fertilizer, combined with bone meal to supplement phosphorus. Varieties such as Cymbidium and Cattleya require annual supplementation of 3 times with orchid-specific slow-release fertilizer to ensure balanced N-P-K supply (recommended ratio 20-20-20).
Acid-Base Control: Variety Adaptation Principle
Black orchids and Cymbidium prefer a slightly acidic environment with a pH of 5.5-6.0, which can be adjusted with sulfur powder; epiphytic varieties like Phalaenopsis require a pH of 6.0-6.5. It is recommended to test with pH paper monthly and adjust immediately when the deviation is >0.5.
Practical Guide to Improving Common Soil
Three-in-One Formula Improvement Method
Garden soil needs to be disinfected at high temperatures and mixed with decomposed leaf soil and coarse river sand in a ratio of 3:4:3, with the addition of 10% pine scales to enhance porosity. This formula reduces costs by 60% while achieving 80% of the cultivation effect of a professional matrix.
Regional Raw Material Alternative Solutions
In the south, crushed coconut shell can be used as an alternative to pine bark, and in the north, oak sawdust can replace decomposed leaf soil. The key is to ensure a mixture porosity of >35% and a bulk density of <0.8g/cm³.
Through scientific soil mixing and meticulous management, even common soil can be used to cultivate high-quality orchids with lush leaves and abundant flowers. It is recommended that growers adjust the formula flexibly based on variety characteristics and regional conditions, and regularly observe the plant's condition to optimize the cultivation plan.