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Yellow Sweet Blossom Clover Cover Crop

Standard · Fabaceae

Yellow sweet blossom clover is a vigorous biennial legume cover crop with a deep taproot that helps loosen compacted soil and add nitrogen over time. It is valued as both a green manure and a strong bee plant, especially if allowed to flower in the second season. In gardens it is usually seeded in cool weather and managed for root depth, soil coverage, and biomass rather than as a harvest crop. Key facts: 60–90 days to maturity, 6+ hours of sun, 6–10 " spacing. Not recommended for containers.

Updated April 19, 2026 · Backed by 3 cited sources
Overview

At a Glance

The essentials first: timing, light, spacing, seed-starting, container fit, and overall size.

Days to maturity
60–90 days
Sun
6+ hours
Full Sun, 6 8+ Hours
Spacing
6–10 "
between plants
Seed start
0 weeks
before transplant
Container
Not recommended
Needs 5+ gal if attempted
Height
2–5 ft
at maturity
Planting window

Zone Planting Guide

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Care

Growing Guide

Everything in one place: seed starting, transplant timing, watering, soil, and structural support.

Seed starting
Germination
Time7–14 days
Optimal temperature60°F
Seed depth0.5"
Moving outdoors
Transplanting
Minimum soil temp45°F
Harden off0 days
Moisture
Watering
Weekly0.75–1.25 "
NeedsModerate
Overhead or base watering during establishment
Root zone
Soil
pH range6.5–8
PreferredModerately Drained Loam Or Clay Loam With Neutral To Alkaline Tendency
Resilience

Plant Health

Stress tolerance, resistance notes, and the most common problems to watch for as plants mature.

Tolerance
Heat: Moderate Cold: High Drought: High

Common Issues

Thin Stand

Cause: Late dry sowing can reduce establishment and second-year production.

Prevention: Sow in cool moist periods and use a firm seedbed.

Sweetclover Weevil

Cause: Weevil feeding can weaken stands in some areas.

Prevention: Rotate sites and monitor stands if sweetclover is grown repeatedly.

Volunteer Seeding

Cause: Second-year plants can reseed if left too long.

Prevention: Terminate before viable seed forms if volunteers are unwanted.

Feeding & picking

Nutrition & Harvest

How hungry the plant is, what ripe harvest looks like, and how long the crop keeps after picking.

Feeding
Nutrition
Feeding intensityLight feeder
RecipesWorm Castings Topdress
Timing
Harvest

Mow, crimp, or chop down once the stand has produced good biomass but before unwanted seed set.

Expected yield0.05–0.3 lbs/plant
Storage Usually incorporated, chopped in place, or used as surface mulch rather than stored.
Plant relationships

Companion Planting

Helpful neighbors can support growth or deter pests. Keep antagonistic plants separated to reduce stress and competition.

Avoid planting near
Herb Fennel
What you'll need

Growing Supplies

Based on Yellow Sweet Blossom Clover's growth profile -- recommendations matched to this variety's specific requirements.

Drip irrigation / soaker hose kit

Every gardener benefits from putting water at the root zone instead of on the leaves, because drip and soaker systems reduce foliar disease pressure by limiting leaf wetness and soil splash. A quality kit should include a backflow preventer, filter, pressure reducer, and UV-resistant tubing.

Source: Iowa State University Extension; Colorado State University Extension; UMass Extension

Soil test kit

A soil test gives a baseline for pH and nutrient status so gardeners can add only what the soil actually needs. Prioritize a mail-in or lab-affiliated kit whenever possible because extension guidance notes that laboratory testing is more accurate than instant readers.

Source: University of Maryland Extension; Purdue Extension; Montana State University Extension

Quality bypass pruners

Extension guidance favors bypass designs because they make cleaner, closer cuts on living tissue than anvil types. Look for hardened steel blades that can be sharpened, a comfortable grip, and a cutting capacity matched to real home-garden stems.

Source: University of New Hampshire Extension; Iowa State University Extension; Purdue University Extension

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Research

Sources

Reference material and extension guidance used to build this growing guide.

seed_catalog Seeds Nowuniversity Mississippi State Extensionreference Sweetclover agronomy references
Internal links

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