Genista germanica aka German Greenweed

Genista germanica, or German broom, is a small deciduous shrub. It belongs to Fabaceae, the pea family. Its native range lies in central and western Europe. It is not native to Britain or Ireland. Wild plants grow in thickets, poor pastures, and on heaths. These habitats include open ground with soils low in nutrients. In gardens, the shrub reaches about 2 feet [0.6 metres] tall. It loses its leaves for winter.

Flowers appear from June to July, and bees pollinate them. Each flower has both male and female parts. The roots host bacteria that form nodules and fix nitrogen. The shrub uses some of the nitrogen these bacteria supply. Nearby plants may also gain from this process. This makes nitrogen fixation one of its useful garden traits. The supplied species account gives no further flower or fruit details.

Choose a sunny spot with soil that drains well. This shrub cannot grow in shade. Sandy and loamy soils both suit it. It grows in poor soil and prefers rather dry conditions. It also accepts moist soil and can withstand drought. Its soil pH range extends from very acid to very alkaline. Rich soil can lead to too much growth. PFAF lists USDA hardiness zones 4–8. Plant it in its final position while still young. Its roots dislike disturbance, so avoid moving established plants.

German broom suits planted beds and sunny woodland edges. Its small size makes it a low shrub for these sites. The plant also yields a yellow dye. People once grew it for medicine, but the source gives no details. PFAF records no known edible uses and rates its food value at zero. It lists no known hazards, but this does not establish food safety. The evidence names no specific pests or diseases. PFAF does not flag it as a weed.

Grow new plants from seed or from wood cuttings. Seed needs a period of cold treatment before it sprouts. Sow fresh seed in a cold frame in autumn. Soak stored seed in warm water for 24 hours before sowing in February. Move seedlings into separate pots when large enough to handle. Plant them out in summer. Take half-ripe heel cuttings in July or August. Ripe heel cuttings are another option in September or October.