On 9/22/2008 7:04 AM, Chris Nelson wrote [in part]:
On Sep 21, 11:22 pm, I also wrote [also in part]

If it blooms in the spring, prune it right after it blooms. If it
blooms in the summer, prune it just as the leaf buds start to swell in
the early spring. Entire branches should be removed; a branch that is
merely headed will heal very slowly and might die.

Well, where's a "branch" start/end? Can I trim it at any fork or do I
have to go back to the trunk? Should I seal the end where I prune?

Trim to a fork. I use white glue (Elmer's, Willhold, GluBird, etc) to
seal any pruning cuts larger than the diameter of a pencil. Do NOT use
a tar-based pruning paint, which can cause further damage.

Do not try to grow anything under it. Planting under it is not good for
the magnolia itself. It cannot take repeated disturbance of surface
roots (e.g., to plant annuals, divide bulbs and perennials, or aerate a
lawn) in its root zone. It also does not like foot traffic in its root
zone.

Unfortunately, it's in sandy soil on a slight grade and I'm getting
erosion. I can live with it not being grass (so there isn't foot
traffic mowing and aeration, etc.) but I need something there to hold
the soil. A low-lying ground cover is fine. Any recommendations?

A low-maintenance perennial or woody ground cover should be okay. It
will also discourage foot traffic. My Sunset "Western Garden Book"
specifically says not to plant a lawn in the root zone but that
magnolias do well in shrub beds.

--
David E. Ross
Climate: California Mediterranean
Sunset Zone: 21 -- interior Santa Monica Mountains with some ocean
influence (USDA 10a, very close to Sunset Zone 19)
Gardening pages at http://www.rossde.com/garden/