Buy OSRS Belladonna seed
The Belladonna seed is a Farming seed in Old School RuneScape. Players plant it in a belladonna patch. These patches are found at Draynor Manor and Auburnvale. Planting it needs level 63 Farming.
The seed grows into nightshade. Nightshade is used in Herblore to make weapon poison(++). It can also be added to dynamite to make poison dynamite. Harvesting nightshade is a task in the hard Lumbridge and Draynor Diary.
Planting the seed gives 91 Farming XP. Harvesting gives 512 XP. The plant takes 320 minutes to grow, which is about 5.3 hours. Each patch holds one seed. The minimum yield is six nightshade, and a higher Farming level can raise the yield. The most you can get is 18 at level 99. Magic secateurs do not raise the yield.
No gardener will watch the patch, so using compost is a good idea. Players must wear gloves when picking nightshade, or the plant will deal 2 poison damage instead. Some hand slot items, like the regen bracelet, also work. If the plant gets diseased, plant cure or the Lunar spell Cure Plant can fix it.