Checked underneath the leafs and nothing, now you've both mentioned it I feed them just with watering can but spilt some on this plant last time didn't cross my mind but think it probably is burned from water droplets.
Thanks
Hi,
My autos are 7 weeks lots of brown coloured rust spots appeared overnight. Mainly on the top leaves, also got red stems but been like this for weeks the spots only just appeared. Been looking and maybe a calmag deficiency so added some today.
Any ideas?