This is my third year growing wildflowers in planters. My planters are
2'x8'x12" high and this year I added two more for a total of five. The
three from last year I did a fall seed planting, first time I did this in
a planter. There seems to be problems in all boxes.

Baby's breath: In the past years this plant, one of the first to bloom,
was merely an accent plant. This year this plant was very aggressive and
acted like an invasive weed choking the growth of all other plants in the
boxes. In one box I failed to act until the flowers waned and then after
pulling the baby's breath I was left with a relatively bare box.

Before pulling:
http://www.brandylion.com/gallery/Garden2005/119_1918

After pulling:
http://www.brandylion.com/images/after-pulling.jpg

This box, planted in the spring, has the same problem:

http://www.brandylion.com/gallery/Garden2005/120_2036

There's also a bare spot in that box that I can't figure out. I keep
reseeding it but nothing wants to grow there.

Here in Chicago we're suffering from a pretty bad drought requiring me to
water everything every day. I water heavily yet all the wildflower
planters dry out after one full day in this 90+ degree heat. I'm
wondering if perhaps that the severe lack of rainfall in the Spring
stunted the other plants allowing an invasive plant like baby's breath
to take over. I'd like to figure this out so I don't make the same
mistakes next year.