Herbs are a Farming plant that grows after planting a guam seed in a herb patch, requiring level 9 Farming. They take 80 minutes to grow, in 4 stages of 20 minutes each, and when fully grown can be harvested for grimy guam leaves.
When herbs get diseased, they will become diseased herbs, and can be cured using plant cure. If not cured, they will eventually become dead herbs.
As with all herb patch crops, nearby gardeners will not watch over growing guam.
The yield is variable, using the "harvest lives" mechanic with a minimum of 3 lives. The number of lives can be increased by 1 using compost, 2 using supercompost, or 3 with ultracompost. The chance to save harvest lives is improved with higher Farming level, and can be further improved using magic secateurs, the Farming cape, or having a growing Attas plant. Additionally, completing the Kandarin Diary will improve the yield in the Catherby herb patch, and the Kourend & Kebos Diary will improve the yield in Hosidius and the Farming Guild.
- ^ This experience is gained upon harvesting the final herb, rather than when planting the seed.
- ^ Only dropped by Grown version.