Q.Creating a Rock Garden
I am creating a rock garden in SF. The house faces east. I am purchasing Salmon Bay decorative rock, a few Aloe Vera, several Phormium and Spanish Lavender for a rock garden. I have no gardening experience, and I am not installing any irrigation system. Are these plants easy to maintain? A friend had suggested English Lavender, but my gardener feels Spanish Lavender is easier than English Lavender. A discussion online indicates that English Lavender is hardier. Please let me know.

Certified GKH Gardening Expert
It really depends on what kind of environment you live in. Spanish lavender is a hardier lavender if you are in a very warm climate. It comes from Africa, so they like the heat.
You are in SF, which is known for its fog. English lavender does not tolerate this kind of humidity well. It prefers a drier climate.
So, given these two things, I would agree with your gardener that the Spanish variety is best.
Aloe and Phormium are also very easy to maintain once established.