They like quite a lot of water.
You mention that you intend to plant 2 in the garden. Did you mean plant for a while to grow out trunks and ultimately be dug up and grown in containers as bonsai or did you mean plant in the garden as landscape trees? If it’s the latter, you’ll want to really do your homework first to understand what you’re potentially getting into. Sequoia roots grow aggressively, stay fairly shallow, and extend further away from the trunk than you may imagine. Damage to the home’s foundation is a possible complication if it’s planted too close. In an urban/suburban setting where they don’t have to compete with an established forest for sunlight, they may also grow significantly taller and in less time than you might expect.