The First 48 hours are especially critical for success
- Every tool, surface, and hand that the cutting touches should be disinfected. Pay special attention to carts.
- Open boxes immediately.
- Open plastic bags and place on clean, disinfected card shelves in a 50°-55°F (10°012.8°C) cooler with a relative humidity near 100%. Wetting the floor is an effective way to achieve this goal.
- Cuttings should remain in the cooler for a minimum of 4 hours but overnight is best. Morning conditions in the greenhouse are best for sticking cuttings.
- If cuttings appear dry, mist with water to help re-hydrate.
- Remove only the number of cuttings that can be stuck in 1 hour from the cooler.
- A powder rooting hormone such as Hormodin #1 is recommended to improve uniformity in rooting. A powder is less likely to spread disease. Some growers us a K-IBA spray at 100 ppm the morning after sticking. A trial is suggested before treating a large area.
- Mist can be applied to the cuttings during sticking to reduce stress.
- Leaves should be “tucked” so growing points (apical meristems) are not covered by leaves. Make sure the growing points remain uncovered throughout propagation.
- Apply Capsil at a rate of 1-4 oz./100 gal. (58-113 g/379 L) of water to the cuttings immediately after sticking. Capsil will help the cuttings recover from any wilting as well as improve rooting.
- The misting area should be shaded for a max. of 1,200-1,500 foot-candles (12,000-16,000 LUX) of sunlight.
- Set mist frequency and duration to maintain a film of water on cutting leaves. Avoid excess free water from over-misting. Mist should be applied at night until the cuttings have regained turgidity.
- Root medium temperature should be maintained at 70°F (21°C) during rooting. Reduce mist frequency as cuttings begin to root.
- Apply a low rate of fertilizer (100 ppm N) as soon as roots begin to form even though the cuttings are still under mist. Avoid Phosphorus on leaves to prevent leaf distortion.
- Carefully monitor fungus gnats during propagation and apply an insecticide during propagation as needed.
- As cuttings root, mist should be reduced, bottom heat can be eliminated, sunlight levels should be increased, and fertilizer increased to acclimate liners to the greenhouse environment for transplanting.
- By the end of propagation (4 weeks), liners should be acclimated to full sunlight.
- Plot rooted liners immediately.
- Plants should be watered-in with a fertilizer solution and fertilizer applied at each watering thereafter. Plants watered overhead with phosphorus should be rinsed with clear water to avoid phosphorus-induced leaf distortion.
- Until roots grow into the new soil media, carefully monitor irrigation the first week after potting as the recently-transplanted liners may need water before the rest of the pot requires water.
- All poinsettias, both direct-rooted or potted-liners, should be pinched when the new roots reach the edge of the finish container.
- New roots will normally reach the edge of the pots within 10-14 days after transplanting liners of 4 weeks after direct sticking unrooted cuttings.
- Pinching plants at this stage will improve the uniformity of branching and greatly improve plant growth and form.
Information from Dummen Orange – updated 7/11/2017