Summer Plant Propagation Guide: Hormex Rooting Powders

Summer is the absolute sweet spot for plant propagation. With long daylight hours and warm soil temperatures, plants are actively pushing out soft, tender growth that is bursting with natural energy.

Taking stem cuttings during the summer, specifically softwood (fresh green growth) and early semi-hardwood (stems that are starting to firm up at the base) gives you the highest success rate of the year. But to jumpstart root development before the heat stress sets in, using the right concentration of rooting hormone is essential.

Here is a breakdown of the best plants to propagate this summer and exactly which Hormex Rooting Powder strength to use for each.

1. Softwood Cuttings (Early to Mid-Summer)

Softwood cuttings come from the flexible, non-woody tips of spring and early summer growth. Because these stems are delicate, they require a lower strength hormone to prevent system shock or tissue burning.

Hormex Rooting Powder #1 (Lowest Strength)

Best for: Soft stem tender annuals, houseplants, and quick-rooting perennials.

  • Chrysanthemums & Dahlias: Ideal for multiplying your autumn flower displays early in the season.

  • Coleus, Pothos & Philodendrons: Take 4–6 inch tip cuttings; they root effortlessly in moist perlite or peat mixes.

  • African Violets & Geraniums: Soft tissue roots quickly without rot when given a light coating.

2. Semi-Hardwood & Flowering Perennials (Mid to Late Summer)

As summer progresses, stems begin to mature. They aren't fully woody yet, but they have enough rigidity to snap when bent. These need a moderate hormone boost to signal root development.

Hormex Rooting Powder #3 (Moderate Strength)

Best for: Moderate rooters, woody herbs, and flowering garden shrubs.

  • Roses: Summer non-flowering shoots take remarkably well to #3.

  • Hydrangeas: Take 4-inch cuttings from non-blooming stems just below a node.

  • Salvia & Penstemon: Perennials whose growth is starting to firm up at the base.

  • Fuchsias & Pelargoniums: Perfect for securing clones to overwinter indoors.

3. Woody Shrubs & Tough Ornamentals (Late Summer)

By late summer, current-season stems become firm, thick, and semi-woody. Tougher stem tissues demand higher IBA concentrations to trigger cell differentiation.

Hormex Rooting Powder #8 (Higher Strength)

Best for: Moderately difficult-to-root evergreen and deciduous shrubs.

  • Hibiscus & Bougainvillea: Tropical beauties that benefit from a stronger push during peak warmth.

  • Azaleas, Camellias & Rhododendrons: Firm late-summer cuttings need this extra horsepower to break through barky stems.

  • Citrus & Boxwood: Take firm side shoots and treat the exposed stem tissue.

Hormex Rooting Powder #16 (Maximum Strength)

Best for: Severely difficult-to-root woody plants, dense evergreens, and hardwood cuttings.

  • Junipers & Arborvitae: These tough evergreens require the highest IBA concentration to initiate root growth from their rigid, woody stems.

  • Magnolias & Hollies: Notoriously stubborn to propagate, these firm cuttings need maximum hormone stimulation to break through dense outer layers.

  • Grapes & Hardwood Trees: Ideal for late summer shoots that have fully hardened off and require an extra-strength push to root successfully.

Quick Guide: Matching Plant to Powder Strength

Hormex Powder Cutting Type Target Plants
Hormex #1 Tender Softwood Pothos, Coleus, Violets, Geraniums, Chrysanthemums
Hormex #3 Softwood to Semi-Hardwood Hydrangeas, Roses, Salvias, Fuchsias, Lavender
Hormex #8 Firm Semi-Hardwood Hibiscus, Azaleas, Bougainvillea, Citrus, Camellias
Hormex #16 Hardwood / Evergreens Junipers, Magnolias, Arborvitae (Best reserved for autumn/winter)
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