[3] The shape of the leaf blades of the V. phoeniceum can be elliptical, ovate, chordate or lanceolate depending on the environment in which it grows in.

Hybrids may have flower colors ranging from white to various shades of pink and plum; as well as the advantage of a longer growing season due to its perennial nature.

It thrives in USDA’s hardiness zones 4-8,[8] with possible natural occurrence in New York and Ohio where the winter temperatures are also required for seed germination after dormancy.

[4] In a study by Branimir Petkovic et al. 2004, V. phoeniceum were planted on three different substratum soil types, serpentine, andesite and limestone.

[10] The first observation of self-incompatibility in plants was made on V. phoeniceum in the late 18th century and published by Joseph Gottlieb Kölreuter.

Unlike other mulleins V. thapsus and V. lychnitis which are able to self-pollinate, V. phoeniceum pollinated with their own pollen do not set seed but are cross-fertile; this had been attributed to the allotetraploidy of the plant.

However in a study by Tatli et al. 2006, the mentholic extracts taken from the leaves and flowers of V. phoeniceum and other verbascum plants showed strong antimicrobial activity.