Indigofera Species, Hairy Indigo, Roughhairy Indigo

Invasive and persistent in central FL. Seems to like poor sandy soils. Will spread readily. Maybe not an issue in an agricultural setting...Read More but a nightmare for a garden. Roundup does kill it, but it has reappeared in areas where I have hit it with Roundup so seeds must last from one season to the next.If you want to eliminate it, it is imperative to get it before the red flowers show.

It is tough. It fixes nitrogen. It may suppress root-knot and other destructive soil nematodes. Otherwise it is a nightmare in norther...Read Moren peninsular Florida, unless you REALLY want to make your own indigo dye the old-fashioned way (harvest leaves of the blooming plants, mix them with water, and allow bacteria to eat away the sugar group naturally attached to the dye molecule as someone or something keeps agitating the mix to keep it aerated; it's not as good a dye plant as the true indigo in the same genus, but it comes close). Sometimes frost hits early enough here that the seeds are not mature when the plants die, but usually it does not. Seeds can persist in the soil for decades, and disturbing any soil containing seeds increases the risk that they will sprout. (Maybe pre-emergence herbicides help, but I haven't tried them yet.) Some genius at U Florida is alleged to have introduced this plant from Africa some decades back and promoted its use. It is ubiquitous on the sunnier parts of my 36 acres near Gainesville, and if I don't hoe or pull it young it takes over my vegetable garden, rose beds, or anywhere else without a good thick crop of vegetation already present. Cattle MIGHT graze on plants that are very young and still tender, but I understand that it is not a favored food, and that the "hairs" on mature plants irritate grazing animals on dewy mornings. Do not plant this on purpose.

This plant is invasive in Florida and it first came up near my shampoo ginger patch. The seeds are barbed so they attach to clothing eas...Read Moreily and that's probably how they spred so fast. It is a legume and is a good cover crop. I've heard that its leaves can be used to dye fabric blue like the common indigo. Like the name suggests, its leaves are very soft, hairy, and somewhat velvet textured. Its an attractive weed but again invasive. It has pretty red flowers that appear year round.

Erect-prostrate climbing annual, producing heavy foliage on fine stems that become rather coarse in later stages of development. Grows we...Read Morell on poor sandy land. Yields good quality forage that can be used for hay and pasture.

Farmers and ranchers found the plant useful; green cropping (cultivated for plowing under) with the legume improved soil for crops like melons and strawberries and cattle gained more weight when it was part of their forage.

Dougall and Bogdan (1966) analysed I. hirsuta forage as containing 23.8 percent crude protein, 2.0 percent ether extract, 15.2 percent crude fibre, 46.8 percent nitrogen-free extract, 1.88 percent calcium and 0.37 percent phosphorus, but Kalmbacher et al. (1980) showed that crude protein and in vitro organic matter digestibility are greatly influenced by time of sampling, declining rapidly as the plant material ages. Early cut material contained 24 percent crude protein.

Free-seeding and regenerating readily each year, hairy indigo's tolerance of low soil pH and fertility coupled with its resistance to root knot nematode make it an attractive legume for poor sandy soils in Florida.

I personally use this plant for two purposes: to provide high protien forage for my sheep and to improve soil in old garden areas. It also has nice red flowers that are quite attractive to butterflies, bees and hummingbirds.