Abstract: Root-growth stimulating compounds are applied to plants to stimulate growth of roots on the stem of a plant for air layering. The root-growth stimulating compounds may be applied by wrapping part of the plant with a tape that includes the root-growth stimulating compounds. The tape may include a gel layer that is impregnated or coated with the root-growth stimulating compounds. The root-growth compound may additionally or alternatively be applied to a plant by affixing a clamshell-type device around part of the plant. The device may hold a porous material containing the root-growth stimulating compounds in contact with the plant. Both the tape and the clamshell-type device may block light from reaching the covered portion of the plant thereby causing chlorosis.