Hi there, I grow sweet peas most winters/springs and love them. They do really well here if you give them sun and regular water during the cooler months. I soak mine overnight to help them suck up as much moisture as possible, but it's not absolutely required (but sure doesn't hurt). I grow tall types in containers and in the ground. Just be sure to give them something to climb and to not let their container get top heavy with foliage. They do really really well here if winter planted.

I haven't grown 'Royal Family' specifically, but I've grown a lot of different types. Here's a pic of a big ol' pot from two years ago. This past year I did bush types.

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Let us know what you do, and how it works out!
Happy gardening,
Grant