May 2011

New Rooting Medium for Poinsettias By Jim Faust

Proper propagation techniques can be critical to your poinsettia crop's success. New research from Clemson University looks at a new rooting medium that growers may want to consider this poinsettia season.

Researchers have developed a new rooting medium that is specially designed for poinsettia propagation. Now commercially available, the product is named Oasis Wedge Plus for poinsettias.

Experiments were conducted at Clemson University with the new rooting medium on 'Prestige Red', 'Freedom Red' and 'Prestige Early Red'. Rooting evaluation at Day 20 after sticking demonstrated that the rooting of all three poinsettia varieties was faster and uniform in this new rooting medium.

In general, the poinsettias stuck into the new rooting medium were ready to transplant five days ahead of their counterparts propagated in the original foam formulation of Oasis Wedge. The results with 'Prestige Red', 'Freedom Red' and 'Prestige Early Red' are demonstrated in Figure 1 (below).

While growers can be successful propagating poinsettias in the original or the new rooting medium, the faster rooting of the new product improves efficiency by allowing more plants to cycle through a fixed space propagation area.

Keys to Poinsettia Propagation

Successful poinsettia propagation begins with sound cultural practices regardless of the propagation medium used. Below are a few helpful tips when using Oasis growing media.

Prior to rooting: Water in Oasis rooting medium is more freely available to unrooted poinsettia cuttings in comparison to a peat-based growing media. Cuttings can take water out of the rooting medium very easily and efficiently. Therefore growers can reduce excessive misting of cuttings prior to root initiation when using this type of rooting medium. Excessive misting can contribute to nutrient leaching as well as promote pathogen growth.

After rooting: Once cuttings are well rooted in the rooting medium, they will continue to remove the water from the medium very efficiently. As a result, moisture levels need to be closely monitored in the rooting medium on a daily basis. Since this type of growing medium can't be overwatered, it is better to irrigate if there is any doubt in mind.

At transplanting: Saturate the rooting medium prior to transplant and then water-in the container media after transplant. It is not required to water excessively during the first few days after the transplant. Many growers tend to overwater at this stage and delay the root growth as a result. Healthy roots will emerge into the surrounding media within 48 hours after transplant if these steps are performed.