Rooting hormone is a product used in plant propagation to stimulate root growth in cuttings. This substance contains auxins, which are plant growth regulators that encourage cell division and differentiation at the base of a cutting. Finding the appropriate type and strength of this hormone depends on the specific plant material being propagated and the desired application method.
Types of Rooting Hormone and Application Methods
Rooting hormones are primarily formulated using two synthetic auxins: Indole-3-butyric acid (IBA) and Naphthaleneacetic acid (NAA). IBA is the more common and milder of the two, often preferred for softwood and semi-hardwood cuttings like common houseplants and shrubs. NAA is more potent and is reserved for difficult-to-root species or woody cuttings, though many commercial products blend both for a wider application range.
The hormone is sold in three main forms. Powder is the most widely available and easiest for hobbyists, requiring the cutting end to be dipped before planting. Gel formulations provide a thick coating, often include fungicides, and are frequently used in hydroponic or high-humidity environments. Liquid rooting hormone offers the greatest flexibility, usable as a ready-to-use solution or as a concentrate diluted to specific strengths (measured in ppm) for a quick-dip treatment.
Softwood cuttings generally require lower concentrations (500–3,000 ppm), while hardwood cuttings need much higher strengths (6,000–10,000 ppm). Liquid concentrates allow for precise dilution, making them the preferred choice for commercial growers dealing with a variety of plant types. The simpler powder and gel forms are sufficient for most common home propagation tasks.
Purchasing Rooting Hormone at Physical Stores
Physical retail stores offer convenient access to common rooting hormone products for immediate needs. Big box stores and large home improvement centers stock general-purpose powder hormones, usually in lower concentrations suitable for easy-to-root plants. While widely available and low cost, the selection is limited, and these locations rarely carry the higher-strength gels or liquid concentrates required for woody or difficult cuttings.
Local nurseries and independent garden centers offer a more diverse selection, often including higher-quality or specialized powder and gel formulations. Purchasing from these retailers provides the added benefit of expert advice from staff who can help match the right product concentration to the specific plant being propagated. While prices may be higher than at larger chains, the specialized stock can be invaluable for propagating less common plants.
Agricultural supply stores cater to commercial farming and serious hobbyists. These locations may stock bulk sizes or professional-grade products not found in standard garden centers. They are the most likely source for finding the higher-concentration powders and liquid concentrates necessary for large-scale propagation projects or for rooting challenging, woody plant material.
Sourcing Rooting Hormone Online and Through Specialty Retailers
Online purchasing offers the most comprehensive selection of rooting hormone products, especially for those seeking professional-grade or bulk quantities. Major e-commerce platforms provide convenience and competitive pricing on popular brands. However, buyers should exercise caution regarding product freshness and authenticity, as hormone effectiveness degrades over time. Verifying the seller’s reputation and checking for explicit expiration dates is advisable.
Specialized horticultural supply websites cater directly to commercial growers and offer a vast array of high-concentration liquids and gels that are difficult to find locally. These retailers often stock pure IBA or NAA powder, allowing advanced users to create custom solutions tailored to specific propagation protocols. For those needing large volumes or a particular formulation, these websites are the most reliable source for consistent supply and product variety.
Purchasing directly from the manufacturer’s website guarantees the freshest product with the longest possible shelf life. Manufacturers often provide detailed technical specifications, application guides, and information on the exact concentrations of IBA and NAA within their products. This direct approach is preferred by serious propagators who rely on the hormone’s maximum potency for successful results.
Practical Buying and Storage Considerations
When selecting a rooting hormone, compare the price per unit of active ingredient rather than just the container price. Higher-concentration products are more expensive initially but can be diluted or used sparingly, providing greater long-term value. Products that include fungicides are beneficial, as they help prevent fungal decay in the cutting while it attempts to root.
Rooting hormone has a limited shelf life, typically ranging from 18 months to four years, depending on the formulation and storage conditions. It is important to check for a “best by” or expiration date on the packaging, as the active ingredients degrade over time, reducing their efficacy. Powder forms tend to be the most stable, while liquids and gels degrade faster, particularly once opened.
Proper storage is necessary to maintain the hormone’s potency. The product should be kept sealed tightly in its original container, stored in a cool, dark place, away from direct sunlight and excessive heat. To prevent contamination and degradation of the remaining product, never dip a cutting directly into the original container. Instead, pour a small working amount into a separate, clean dish and discard any unused portion.