Troubleshooting
Broad-leaved Thyme problems — and how to fix them
Broad-leaved Thyme (Thymus pulegioides) 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.
Legginess without pruning
Without annual cutting back, plants become open and woody with reduced aromatic leaf production. Trim stems by up to one-third immediately after flowering in midsummer. Never cut back into bare, leafless old wood.
Root rot in heavy soils
On poorly drained sites, particularly in wet winters, root rot develops rapidly. Improve drainage with grit before planting or grow in raised beds. Container plants must have drainage holes and be raised on feet to allow free drainage.
Aphid infestations on new growth
Soft spring growth can attract aphid colonies, particularly greenfly. Treat with a strong water jet or insecticidal soap. Avoid high-nitrogen fertilisers, which promote the soft growth that aphids prefer.
Prevent broad-leaved thyme problems before they start
Most broad-leaved thyme issues are care-mismatch, not bad luck. Dial in the basics:
Looking for broad-leaved thyme in general rather than its problems? Read the full broad-leaved thyme care guide — light, water, soil and feeding.
Broad-leaved Thyme problems — FAQ
Why is my broad-leaved thyme legginess without pruning?
Without annual cutting back, plants become open and woody with reduced aromatic leaf production. Trim stems by up to one-third immediately after flowering in midsummer. Never cut back into bare, leafless old wood.
Why is my broad-leaved thyme root rot in heavy soils?
On poorly drained sites, particularly in wet winters, root rot develops rapidly. Improve drainage with grit before planting or grow in raised beds. Container plants must have drainage holes and be raised on feet to allow free drainage.
Why is my broad-leaved thyme aphid infestations on new growth?
Soft spring growth can attract aphid colonies, particularly greenfly. Treat with a strong water jet or insecticidal soap. Avoid high-nitrogen fertilisers, which promote the soft growth that aphids prefer.