Rooting Hormones -- Gels, Powders & Liquids for Plant Propagation
Rooting hormones contain plant growth regulators -- primarily indole-3-butyric acid (IBA) and occasionally naphthaleneacetic acid (NAA) -- that stimulate root initiation at the base of cuttings. Applying a rooting hormone to a freshly cut stem before propagation significantly increases rooting success rates, accelerates the time to visible root emergence, and produces more uniform root structures compared to unassisted cuttings. Whether you are propagating in an aeroponic cloning machine, rockwool cubes, soil, or water, a rooting hormone applied to the cut surface is the most reliable single-step improvement available to any propagation workflow.
Rooting Hormone Formats: Gel, Powder & Liquid
Rooting hormones are available in three formats with different handling characteristics and application methods. Rooting gel is the most widely used format in hydroponic and soilless propagation -- thick, clear gels (Clonex is the category standard) coat the cut stem surface and adhere through the rooting period, maintaining IBA contact at the cut surface and sealing the wound against desiccation and pathogen entry simultaneously. Gels are applied by dipping the cut stem directly into the gel container or a small working dish -- never dip cut stems directly into the main gel container as this introduces contamination. Rooting powder is the traditional format -- IBA or NAA in a talc carrier applied by dusting the damp cut stem base. Powder works well for woody cuttings and outdoor propagation; it is less commonly used in hydroponic aeroponic cloners where the misting environment can wash powder off the stem before it takes effect. Liquid rooting hormones (diluted IBA solutions) are used as soaks for cuttings or as drench treatments for seedling root development stimulation.
Rooting Hormone Brands: Clonex, Hydrodynamics & Grodan
Hydrobuilder carries rooting hormones from qualified brands including Clonex by Hydrodynamics International (the most widely used rooting gel in commercial and hobby propagation), Olivia's Cloning Gel, Technaflora Rootech, and Grodan Rooting Plugs (which come pre-inoculated with a rooting stimulant). Clonex gel contains 3,000 ppm IBA (indole-3-butyric acid) in a water-soluble gel base -- the standard concentration in professional propagation programs. It is also pH buffered to support root development and contains vitamins and minerals that support early cutting health through the rooting phase.
Rooting Hormones for Different Propagation Methods
For aeroponic cloning machines, rooting gel (Clonex) applied to the cut stem base before insertion into the neoprene collar is the standard approach. Gels are resistant to the misting environment inside aeroponic cloners. For rockwool propagation under humidity domes, both gel and powder work well -- apply gel to the cut stem, then insert directly into a pre-soaked rockwool cube. For soil or coco propagation, powder or gel applied to the cut stem base before insertion into a pre-moistened propagation medium produces reliable results. For water propagation (placing cuttings directly in water), rooting gels are optional but beneficial -- a dilute liquid rooting hormone solution in the propagation water provides ongoing IBA contact through the full rooting period.
Pair rooting hormones with a aeroponic cloning machine, browse complete propagation supplies including humidity domes and heat mats, or explore rockwool propagation cubes. Fast shipping.
Rooting Hormones FAQ
Do rooting hormones actually work?
Yes, consistently and measurably. Controlled comparisons between treated and untreated cuttings of the same variety under identical conditions reliably show rooting hormone treatments producing faster root emergence (typically 20-40% faster), higher success rates (10-30% improvement over untreated), and more uniform root structures at transplant. The active ingredient (IBA at typical concentrations of 1,000-3,000 ppm in most products) is a well-characterized plant hormone that triggers root initiation in plant stem tissue. The improvement is most significant for difficult-to-root varieties, woody cuttings, or any propagation scenario where passive root initiation is slow or inconsistent. For easy-to-root varieties propagated under ideal conditions, the improvement is smaller but still present.
What is Clonex rooting gel and how do I use it?
Clonex is a water-soluble rooting gel containing 3,000 ppm IBA (indole-3-butyric acid), vitamins, and minerals. It is the most widely used commercial rooting gel in hydroponic propagation. To use: pour a small amount of gel into a clean working dish (do not dip cuttings directly into the main container -- this introduces contamination). Take your cutting with a clean, sharp blade at a 45-degree angle just below a node. Immediately dip the cut stem base 0.5-1 inch into the Clonex gel, coating the wound completely. Insert the gel-coated stem into your propagation medium (neoprene collar, rockwool cube, or propagation plug) within a few seconds of gel application, before the stem surface begins to dry or callous. The gel seals the wound, delivers IBA directly to the cut surface, and maintains contact through the rooting period.
What is the difference between rooting gel, powder, and liquid?
Rooting gel (Clonex, Olivia's, Rootech) is thick and adherent -- stays on the cut stem surface through handling and in misting environments. Best for aeroponic cloners, hydroponic propagation, and any application where washing off is a concern. Rooting powder (IBA or NAA in talc) adheres to damp stem surfaces and works well for woody cuttings and outdoor propagation where the heavier talc base is appropriate. Less suited to aeroponic cloners where misting washes powder off quickly. Liquid rooting hormones are diluted IBA solutions used as soaks or drenches -- useful for treating large numbers of cuttings simultaneously or for adding rooting stimulant to propagation water. Most indoor hydroponic growers use gel for reliability and ease of application.
How do I prevent contamination in my rooting gel?
Never dip cut stems directly into the main Clonex or rooting gel container. Instead, pour a small working amount into a clean shot glass or dish for each propagation session. Discard any gel that has contacted stems or been exposed to grow room air. Store the main container sealed in a cool, dark location -- temperature extremes degrade rooting hormones. If gel changes color (from clear/green to brown) or develops an unusual odor, discard and replace. Contaminated gel can introduce bacteria or fungi to cuttings at the point of highest vulnerability -- the freshly cut wound. The extra few seconds to use a working dish is the single most effective step in preventing propagation failures related to gel contamination.
Should I use rooting hormone in an aeroponic cloner?
Yes -- rooting gel applied to the cut stem base before inserting into the neoprene collar of an aeroponic cloner meaningfully improves rooting speed and success rates, even though aeroponic cloners already produce excellent results without it. The gel adheres through the misting environment (unlike powder which can wash off) and maintains IBA contact at the wound during the first critical 48-72 hours when root primordia are initiating. Aeroponic cloners already provide the ideal environment for rooting -- the addition of gel amplifies their performance rather than compensating for any limitation. Most serious propagators using aeroponic machines also apply rooting gel as standard practice.
