Hello, we have a grapevine which is over 20 years old and produces beautiful sweet red grapes. This year's crop, while still green, has black spots on a lot of the grapes. What is the best way to treat this? Many thanks Lisa

Hi Lisa, that sounds like black rot, it starts out as brown spots on the fruit, as the disease spreads it will cause the fruit to rot. It is a hard disease to control, and once it is there try and minimise the damage for next season. Remove affected fruit and collect up fallen fruit and dispose of in the rubbish, don't compost or leave in the soil to spread. The best time to control is at bud burst, regular sprays of a copper based spray before bud burst and through winter may help, your local garden centre may be able to recommend a suitable fungicide spray. See another question relating to black rot here https://tuigarden.co.nz/garden-questions/i-have-black-rot-on-my-grapes-what-can-i-do/. Lianne