Scotch broom
Also known as
Common broom, English broom, Broom, Scot's broom
Keep this plant’s care guide close at hand.
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Cytisus scoparius, commonly known as Scotch broom, is a fast-growing, deciduous to semi-evergreen shrub in the pea family (Fabaceae). It forms a dense, twiggy mound of green, ridged, broom-like stems with sparse, trifoliate leaves that often drop in summer, leaving photosynthetic stems. In late spring to early summer, the plant is smothered in bright yellow, pea-shaped blossoms that attract bees and other pollinators. Flattened black seed pods follow, twisting to explosively release seeds. Scotch broom thrives in poor, sandy or gravelly, sharply drained soils and is highly drought tolerant once established thanks to deep roots and nitrogen-fixing nodules. It prospers in full sun and open, windswept sites but languishes in shade or heavy, waterlogged substrates. The shrub is relatively short-lived (5–10 years) and resents cutting into old wood; light, post-flower pruning maintains shape and vigor. While a valuable choice for tough, low-input sites, it is invasive in many regions outside its native range, so verify local regulations and avoid allowing seed set where naturalization is a concern.
Taxonomy
Properties & Requirements
How to care for Scotch broom
Water
Water newly planted shrubs deeply once weekly during the first season, letting the top 5–8 cm of soil dry between waterings. Once established, Scotch broom is very drought tolerant and often needs no supplemental water. In prolonged drought, give an infrequent, deep soak rather than frequent light irrigation. Avoid soggy conditions at all times—winter wet is more damaging than summer dry. For container plants, water when the top third of the mix is dry, then drain thoroughly; never leave the pot standing in water.
Light
Provide full sun for best flowering and compact growth—aim for 6–8 or more hours of direct light daily. Light shade is tolerated but reduces bloom and encourages legginess. In very hot inland climates, brief late-afternoon shade can reduce heat stress without sacrificing flowers. Avoid deep shade, where stems elongate and may flop. Indoor culture is unsuitable; this shrub requires unfiltered outdoor sun and moving air. Keep competing vegetation low so the canopy receives unobstructed light.
Nutrients
Scotch broom is a legume with nitrogen-fixing nodules, so fertilizer needs are minimal. In the ground, avoid rich amendments; excess nutrients reduce flowering and cause lanky growth. If growth is weak on very poor soils, apply a light dose of a low-nitrogen, slow-release fertilizer (e.g., 2-4-2 or 4-6-4) in early spring only. Container plants may take a half-strength, low-nitrogen feed monthly during active growth. Do not fertilize after midsummer, and avoid manures or high-salt synthetics.
Temperature
Hardy to roughly USDA Zones 5–8, established plants tolerate winter lows near −20°C (−4°F) in well-drained soils. Ideal growing temperatures are 10–25°C (50–77°F). Young plants are less hardy; protect the first winter in exposed sites. Prolonged heat above 32°C (90°F) with high humidity can stress plants and shorten lifespan; provide airflow and light afternoon shade in hot-summer climates. Avoid frost pockets and waterlogged soils, where freeze–thaw damage can injure roots.
