Gadenin日本語Get the appThe main problems at a glance
Crimson clover is a tough, easy plant and is rarely troubled much. The problems that do appear are almost all linked to wet soil, crowding or still air, so the site and spacing do most of the prevention for you.
| Problem | What you see | What to do |
|---|---|---|
| Aphids | Clusters on shoot tips and flower stems, sticky leaves, distorted growth | Rub or hose them off; encourage predators; soap spray if heavy |
| Powdery mildew | White powdery patches on leaves, leaves yellowing | Remove the worst leaves, improve spacing and airflow, water at the base |
| Crown rot | Plants wilt and collapse, the base darkens and softens | Remove affected plants; improve drainage; avoid overwatering |
| Clover rot | Leaves and stems turn brown and rot in cool, damp weather, often in patches | Remove affected plants; avoid dense sowing; do not grow clovers in the same spot every year |
Aphids
Aphids gather on the soft tips and flower stems in spring. Small numbers do little harm and are usually cleaned up by ladybugs, lacewings and other predators that the clover itself attracts. Rub them off by hand or knock them off with a jet of water. If colonies are heavy, an insecticidal soap spray applied in the evening, away from open flowers, keeps visiting bees safe.
Powdery mildew
Powdery mildew shows as a white dusty coating on the leaves, most often late in the season when plants are crowded or dry at the roots while the air is humid. Remove badly affected leaves, thin crowded plants to open them up, and water at the base rather than over the foliage.
Mildew on the lower leaves as the plants finish in early summer is normal for a winter annual. It matters most when it appears early and spreads to the flowering stems.
Crown rot and clover rot
Rot is the most serious problem and the most preventable. Crown rot follows waterlogged soil: the base of the plant softens and the whole plant wilts. Clover rot is a fungal disease of clovers that spreads in cool, damp weather through dense stands, turning leaves and stems brown. Both are worst in heavy, wet ground and thickly sown patches.
Remove affected plants promptly along with the debris around them. Prevention is about drainage, spacing and rotation: grow crimson clover in free-draining soil, do not sow too thickly, and avoid growing clovers in the same bed year after year.
Prevention checklist
Choose full sun and good drainage, space plants 8 to 12 inches (20 to 30 cm) apart for a flower display, let the soil dry between waterings once established, skip the fertilizer, and rotate where you grow clovers. Plants grown this way rarely need any treatment at all.