I pick as the need and leaf are there. I'm sure there are others who will say specific times are required. You'll want good quality, healthy leaves. Skip the old, "tired" looking leaves. Dry them. Use for tea by themselves or in combination with other herbs, as needed. FataMorgana

I ended up putting my black and red raspberries next to each other. It has been two years now and I have not seen any disease problems. My black raspberries fruit before the reds and overlap a bit with the first crop on my reds but my reds are everbearing and I prune them to get both crops. Rabbits love raspberry plants and even the nasty thorns on the black raspberries don't stop them. If you have summer bearing reds then you'll need to protect the canes over the winter or you won't get berries since they fruit on second year canes. You'll need to protect the black raspberries too since they also fruit on second year canes. Both types of raspberries spread easily, so I would leave a space between them and the veggie garden. Reds spread underground through runners and end up taking over anything planted near them. Blacks are a bit more manageable as they spread by tip rooting so you only have to keep the tips of the canes from touching the ground if you don't want more plants. You can do this through a combination of trellising and pruning.

Let me know. I have quite a few things I could send cuttings of or several types of seeds I could trade.

Native little wild blackberry often has the same 'white dust' on the new growth as the black raspberries. Just because 'all the sites' say a species has a particular characteristic doesn't mean that characteristic is going to definitively separate that species from all others. Species descriptions are maddeningly incomplete. And plants are variable.