With tighter and tighter restrictions on the use of chemicals in floral production, alternative methods to regulate stem elongation and stem height such as DIF and its variation and brushing/shaking have been studied and implemented in greenhouse growing strategies. To add to the grower's chemfree toolbox, another technique is soon to be available.

The technique is using photoselective plastics that absorb far-red (FR) light as greenhouse coverings or shade cloth. Far-red light is the portion of the spectrum plants use to sense they are crowded, which leads to stem elongation ('stretch'). It has been shown that on a very wide selection of plants (most bedding plants, mums, Easter lilies, poinsettias and others) plants grown under FR absorbing plastics are shorter, more compact, and darker green than plants grown under non-selective shade materials that reduce overall radiation by the same amount. Even compared to plants grown on open benches without any additional shade, plants under the photoselective plastics are no taller are usually darker green and are often shorter.

The implications for growers are that these plastics, which can be manufactured as acrylic sheets, polyethylene film, or nonwoven fabric similar to the material used in floating row covers, can be used to cover greenhouses or in internal shading systems to retard stretch. The technique would be most effective during the late spring, summer, and early fall when excess light is a problem and has to be reduced in the greenhouse to reduce heat stress on the plants. Often, when shading plants during the heat of summer, stretch occurs because plants are crowded and the FR signal becomes significant when overall light is reduced. Using the special plastics can reduce or eliminate stretch. While not recommended for late fall, winter, or early spring in areas where light is limiting during this time, the technique dovetails very well with the use of DIF which is effective during these times, but not during the warmer seasons.