I'm interested in growing two types of flowers on a hill located in
Marin County, Calif. The two types of flowers are the California
Poppy and the California Bluebell (Phacelia campanularia). I have two
issues that I'd like help on:

1. Ideally, I'd like to get both plants to bloom concurrently. The
bluebell seems to like to bloom earlier than the poppy but then it is
a bigger plant and might take longer to grow. Does anyone have a good
source on how long it takes different flowers to bloom once the seed
is placed? (Surprisingly, the catalogue companies are pretty sparse
on this information and I get conflicting information when I call
them.) Anyone have thoughts on how to time planting for Calif.
poppies vs Calif. bluebells if you want them to be in bloom at the
same time?

2. The hill I'm going to plant on currently has never been gardened
and has native grass growing on it. I'm looking more for a wildflower
meadow look than a neatly tilled plot of flowers. I'm thinking about
using Roundup to clear some of the area to give the flowers a head
start. The Roundup label says the sprayed area is safe for new
planting after 24 hours. Is it best to plant right after spraying or
wait a few days/weeks until after Roundup has taken effect and the
grass is already wilted.

As someone very new to this hobby, I appreciate any help/feedback.