From our perspective, the single most critical factor in your soil choice is drainage. Our roots are not adapted to waterlogged conditions. Soggy, dense soil is a death sentence, as it suffocates our root system and invites destructive fungal pathogens like root rot. The ideal potting medium must allow water to flow through it freely, providing hydration without waterlogging. A mix that retains excessive moisture creates an anaerobic environment where our roots cannot breathe or function, leading to a rapid and irreversible decline. Therefore, the base of your chosen potting soil must be porous and well-aerating.
We thrive in a lightweight, fluffy medium that strikes a perfect balance between moisture retention and drainage. A high-quality commercial potting mix designed for containers is a good start, but it often requires amendment to meet our specific needs. The perfect blend for us would consist of three key components. First, a base of peat moss or coconut coir to provide slight moisture retention and a loose structure. Second, a generous portion of perlite or coarse horticultural sand; these inorganic materials are non-negotiable as they create essential air pockets and prevent soil compaction. Finally, a moderate amount of well-rotted compost or worm castings is highly beneficial. This organic matter provides a gentle, slow-release source of nutrients that our tender roots can easily access without the risk of fertilizer burn.
Our root systems are most efficient at absorbing essential nutrients when the soil pH is in the range of 6.0 to 7.0. This slightly acidic to neutral environment allows for the optimal solubility of minerals like iron, phosphorus, and manganese. While many standard potting mixes fall within this range, it is a factor you can confirm with a simple pH test kit. A pH that is too high (alkaline) can lock up certain nutrients, making them unavailable to us and leading to deficiencies that manifest as yellowing leaves or stunted growth, even if the nutrients are physically present in the soil.
While we are not excessively heavy feeders, we do require a consistent supply of nutrients to support our rapid growth and prolific flowering. The initial potting soil should be moderately fertile. We appreciate a mix that includes a balanced, slow-release fertilizer or a good amount of compost. This provides a steady food source as we establish ourselves. However, the real key is what you do after planting. As we begin active growth and especially as we develop flower buds, we will benefit greatly from regular supplemental feeding with a water-soluble fertilizer higher in phosphorus (the middle number on the fertilizer package) to encourage those vibrant, abundant blooms you desire.
For our health and your success, please avoid certain materials. Never use garden soil or topsoil in a container. It is far too dense, lacks proper aeration, likely contains weeds and pests, and will compact into a hard, impenetrable mass that our roots cannot navigate. Also, be wary of potting mixes that feel heavy and muddy out of the bag, or those that contain large, un-composted chunks of wood, which can tie up nitrogen as they decompose. The perfect soil for us should feel light, crumbly, and airy in your hands.
