Q.How can I tell when to pick fruit from cape gooseberry bush
I had a gooseberry bush that gave about 6 fruit and died so I threw the fruit in a large pot with my rose and now I have cape gooseberry bushes everywhere. They have fruit on in varying sizes but I don’t know when the fruit is ripe to pick. Is there a way to tell?
Well, it will be interesting to see if the berries are any good. Since you don't have a particular variety (plants grown from seeds produced by a hybrid don't have predictable characteristics), there's no way to tell what size or color or taste the berries will have. The only way to tell is to try them as they get soft, and just before they get soft, to see how they taste. Here are a couple of articles with information on growing gooseberries: https://www.gardeningknowhow.com/edible/fruits/gooseberries/growing-gooseberries.htm