Do I need to add soil to grow orchids on pine bark
As typical epiphytic plants, orchids have unique needs for cultivation substrates. Pine bark has become a popular plant material choice because it is rich in lignin and has strong air permeability. However, many orchid friends are often confused whether they need to add garden soil and how to deal with it to achieve the best results. This article will deeply analyze the pine bark cultivation system and take you to master scientific treatment methods. Analysis of pine bark substrate characteristics The golden rule of plant material ratio Orchid root system has aerial root characteristics, requiring the substrate to have "three degrees": air permeability>60%, water retention 30%, and void content 40%. Experimental data shows that the PH value of pure pine bark is 5.5-6.2 and the porosity reaches 65%, which fully meets the demand. Adding garden soil will reduce the air permeability by 20-35%, and it is easy to harden, so it is not recommended to mix ordinary soil. Nutritional supplementation options can add 5%-10% pine needle soil to supplement trace elements, or mix volcanic rock/ceramsite to enhance drainage. The ratio of perlite to pine bark of 1:4 can extend the water holding time by 2 hours while ensuring root respiration. In the five-step raw material pretreatment stage of scientific treatment, the old bark that falls off naturally is selected and mechanically crushed into 0.5-2cm particles. Laboratory tests show that the moisture content of bark soaked for 48 hours can reach 75%, which improves the decomposition efficiency by 40% compared with direct use. The decomposition fermentation process adopts a high-temperature sealed fermentation method: the bark is put into a black plastic bag and placed in an environment of 40℃. Turn the pile every 15 days for 2-3 months. When the carbon-nitrogen ratio drops to 25:1, decomposition is marked as complete. The key points of sterilization treatment can be soaked in hot water at 80 ° C for 30 minutes to kill 99% of the pathogens. Microwave sterilization (800W/3 minutes) is a more efficient option and is especially suitable for precious varieties.
The systematically treated pine bark substrate increased the survival rate of orchids to 92%, which was 37% higher than that of the untreated group. It is recommended to change the plant material every 12-18 months, combined with regular fertilization, to maintain the continued and healthy growth of orchids.