Some soils are not as rich as others. If you have gravelly, but well-drained soil in a hot area, these cytisus, commonly known as Broom, are the plants for you. They have upright, slender, broom-like branching and yellow flowers. 'All gold' grows to about 5-6' and has bright, yellow pea-like flowers. 'Moonlight' grows to about 5-6' and has green arching branches with soft yellow flowers. 'Osiris' is a more compact variety, growing to about 2' and has golden yellow flowers. All are very hardy and bloom in early summer.
More at: https://www.grownbyoverdevest.com/plants/allgold-warminster-broom/
More at: https://www.grownbyoverdevest.com/plants/moonlight-scotch-broom/
More at: https://www.grownbyoverdevest.com/plants/osiris-scotch-broom/
Cytisus x praecox 'Allgold'
Cytisus scoparius 'Moonlight'
Cytisus x beanii 'Osiris'