From our perspective, the single most critical factor in a pot is the soil's structure. We are not fond of "wet feet." Our roots require a growing medium that provides excellent aeration and drainage to prevent suffocation and the dreaded root rot, while still being able to retain adequate moisture and nutrients to sustain our vigorous growth. A dense, water-retentive soil, like a standard garden topsoil or a heavy potting mix, will compact around our roots, creating an anaerobic environment that is fatal. Therefore, the ideal soil is not a single type but a carefully engineered mix.
The perfect soil blend for us mimics the well-draining, slightly acidic to neutral, and organically rich soils we often find in our native habitats. A high-quality, sterile commercial potting mix designed for container plants is an excellent base. However, to achieve the perfect structure, this base should be amended. We thrive in a mix of two parts potting soil to one part perlite and one part well-rotted compost or worm castings. The perlite is non-negotiable; its white, porous particles ensure crucial air pockets and prevent compaction. The compost provides a steady, gentle release of essential nutrients and improves moisture retention without waterlogging. For an even sharper drainage, some gardeners successfully add a handful of coarse orchid bark or horticultural sand to the mix.
Our ability to access the micronutrients in the soil is heavily influenced by its pH level. We prefer a slightly acidic to neutral soil pH, ideally ranging from 6.1 to 7.5. Within this range, nutrients like iron, manganese, and phosphorus are most readily available for our root systems to absorb. A pH that is too alkaline can lock up these nutrients, leading to deficiencies that manifest as yellowing leaves (chlorosis) and poor overall health. Using a potting mix that contains peat moss can help maintain slight acidity. It is prudent to test the pH of your potting mix occasionally, especially if using tap water which can be alkaline, and amend it with garden sulfur if necessary to lower the pH.
The best soil mix is rendered ineffective if the container itself inhibits drainage. The pot you choose is an extension of our soil environment. It must have multiple, large drainage holes at the bottom to allow excess water to escape freely. A pot that is too large will hold excess moisture around the root zone for too long, increasing rot risk. Conversely, a pot that is too small will constrict our roots too quickly, stressing the plant. A container that is 2-3 inches larger in diameter than the current root ball is ideal for repotting. Using a pot made of a porous material like terracotta can further aid in moisture regulation by allowing evaporation through the pot's walls.
While our soil mix provides a good foundation of organic matter, the confined space of a pot means nutrients are quickly depleted by our fast growth and must be replenished. We are moderate to heavy feeders, particularly during the active growing and flowering season. A balanced, water-soluble fertilizer (e.g., a 10-10-10 or 5-5-5 formula) applied every two to four weeks during spring and summer will support our lush foliage and prolific blooms. Alternatively, a slow-release fertilizer mixed into the top layer of soil at the beginning of the season can provide a steady supply of nutrients. Always ensure the soil is moist before applying fertilizer to avoid root burn.
