Troubleshooting
Sweet alyssum problems — and how to fix them
Sweet alyssum (Lobularia maritima) is generally forgiving once you match its basics, but a few issues come up again and again. Here is what each one looks like, why it happens, and the fix.
Summer heat lull (flowering pause)
In temperatures above 27 °C (80 °F), sweet alyssum stops flowering and may look ragged. Shear plants back by one-third and water consistently; flowering resumes when temperatures cool in late summer or autumn.
Root rot
Overwatering or poor drainage causes rapid crown and root rot, particularly in containers. Ensure excellent drainage and allow the top layer of soil to dry before rewatering. Raised planters with drainage holes are recommended for container growing.
Caterpillars and cabbage white butterflies
As a member of the Brassicaceae family, leaves may be targeted by imported cabbage white caterpillars. Hand-pick caterpillars and eggs from the undersides of leaves. Bacillus thuringiensis (Bt) spray is an effective organic treatment.
Prevent sweet alyssum problems before they start
Most sweet alyssum issues are care-mismatch, not bad luck. Dial in the basics:
Looking for sweet alyssum in general rather than its problems? Read the full sweet alyssum care guide — light, water, soil and feeding.
Sweet alyssum problems — FAQ
Why is my sweet alyssum summer heat lull (flowering pause)?
In temperatures above 27 °C (80 °F), sweet alyssum stops flowering and may look ragged. Shear plants back by one-third and water consistently; flowering resumes when temperatures cool in late summer or autumn.
Why is my sweet alyssum root rot?
Overwatering or poor drainage causes rapid crown and root rot, particularly in containers. Ensure excellent drainage and allow the top layer of soil to dry before rewatering. Raised planters with drainage holes are recommended for container growing.
Why is my sweet alyssum caterpillars and cabbage white butterflies?
As a member of the Brassicaceae family, leaves may be targeted by imported cabbage white caterpillars. Hand-pick caterpillars and eggs from the undersides of leaves. Bacillus thuringiensis (Bt) spray is an effective organic treatment.