There is no doubt that cover crop broadleaves have a positive impact on soil health. From breaking the carbon–phosphorus bond, to exudates that are manufactured by the plant, to the sheer number of deep-penetrating roots, much of broadleaf plants contribution to soil health are still awaiting discovery. Among the other benefits broadleaf plants provide, there is evidence of broadleaf plants functioning as biofumigants that suppress soil pests and root pathogens. Broadleaf plants do not develop mycorrhizal fungi associations and can be included in mixes to promote the efficiency of other mixcomponents that do establish these associations.
Brassicas represent a smaller group of broadleaf plants belonging to the mustard family. This group includes cabbage, collards, mustard, kale, radish, turnip, and rapeseed. While brassicas provide excellent disease suppression, they are not a mychorrizal fungi host and should be used in mixes with a grass specie. Brassicas are generally small-seeded and require a very low seeding rate.