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Melilotus spp.

melilots and sweetclovers

Attracts Pollinators Attracts Butterflies Drought Tolerant Fragrant (moderate)

Overview

Melilotus spp. is a genus of about 20 species of annual and biennial herbs in the legume family (Fabaceae), known as sweetclovers or melilots for the coumarin scent of the drying foliage. Plants grow 1–8 feet (30–240 cm) tall on erect, branching stems carrying trifoliate leaves with finely toothed leaflets. The small pea-type flowers, yellow or white and about 0.2 inch (5 mm) long, are arranged in slender tapering spikes that can reach 4 inches (10 cm); each forms a small one- to two-seeded pod. The genus is native to Europe, Asia, and North Africa and is naturalized across North America and other temperate regions, often along roadsides and disturbed ground. As legumes, plants fix nitrogen and are grown for forage, green manure, and bee forage. Coumarin in the foliage converts to dicoumarol in spoiled or moldy hay, which thins blood and can poison livestock that eat it. Deep taproots let plants withstand drought and open compacted soil. M. officinalis and M. albus are the species commonly sown on poor and alkaline ground where other legumes struggle.

Native Range

The genus is native to Europe, Asia, and North Africa, centered in the Mediterranean region and temperate Eurasia. Melilotus spp. has naturalized widely across North America, South America, and Australia. Plants colonize roadsides, field margins, and disturbed open ground, often on alkaline or compacted soil.

Suggested Uses

Melilotus spp. is sown for green manure, forage, and soil improvement on poor and alkaline ground, and as a nectar source in bee-keeping. The tall spikes draw bees and other pollinators through summer. Deep taproots open compacted soil and add nitrogen when the plants are turned under.

How to Identify

Leaves are trifoliate with three narrow, finely toothed leaflets, and the crushed or drying foliage carries a sweet hay-like coumarin scent. The small yellow or white pea flowers are held in long, slender, tapering spikes rather than rounded heads. Stems are erect and branched, reaching well above surrounding vegetation. Each flower forms a tiny ribbed pod holding one or two seeds.

Appearance

Size & Dimensions

Height1' - 8'

Width/Spread1' - 3'

Colors

Flower Colors

Foliage Colors

Fall Foliage Colors

Bloom Information

Bloom Period

~12 weeks

Spring Summer

Flowering runs from late spring through summer, roughly May to September, with the slender spikes opening from the base upward. Plants bloom in their first or second year depending on species, and the long spikes draw steady bee traffic. Seed sets through late summer.

Detailed Descriptions

Foliage Description

green

Growing Conditions

Sun Requirements

SunFull Sun

Requires 6-12 hours of direct sunlight daily

• Full Sun: 6+ hours of direct sunlight

• Partial Shade: 3-6 hours of direct sunlight

• Full Shade: Less than 3 hours of direct sunlight

Soil Requirements

pH Range6.0 - 8.0(Neutral)

357912

Soil Types

loam sand clay chalk

Drainagewell drained

Water & Climate

Water Needs

Low

Drought Tolerance

Drought tolerant when established

Care & Maintenance

Care Guide

Plants grow in full sun on a wide range of soils, including poor, dry, alkaline, and compacted ground. Established plants reach moisture through a deep taproot and withstand drought, while waterlogged sites are avoided. Nitrogen-fixing root nodules let the genus grow where fertility is low, and no feeding is needed. Biennial species form a leafy rosette the first year and flower the second; annual species flower within one season. Plants self-seed freely and can spread into surrounding ground from a single sowing.

Pruning

Plants are mown or cut before seed sets to limit self-seeding and spread into adjacent ground. Cutting at early bloom is used when the foliage is harvested for hay or green manure. Biennial species die after seeding and are cleared at the end of the second season.