By May, I had blooms of petunias sown in March. If you find the trailing or wave varieties, they work well in windowboxes. You can sow direct and cover them with plastic.

Alyssum and poppies get my vote!

When I direct sow I need to poke holes in the plastic,correct? Also how do you know the amount of seed to place in the window box? Sorrory but I am very green at this,no pun intended. Oh one more question,could I use miracle grow that has fert. already in it?

Thanks,Brian

For the last 3 years, I've grown lobelia, experiment with colors, but am tired of it, may go one more year with it and use up the seeds.

Mine I use for planters to sit around on the ground to add interest (hopefully). The wave petunias are probably good, just had a couple last year, didn't get them started right.

I think I started my white alyssum and transplanted out of a window box. Then I grew a really pretty alyssum mix, crystal? something from T&M, but it didn't last long, was pretty short, and didn't self seed like the white.

I've got geraniums in 2 window boxes but am having trouble finding companion plants as they tend to crowd. The pink is nice with iresine, best, fastest trailing plant I have, but it tends to crowd out other things I've tried like vinca and even my white alyssum wasn't too happy. The iresine I've kept going from a sale rack of wilted stuff for about 5 years now, roots easily in water. I have to shear it off when I bring it in in the fall and sometimes try to thin it out a bit. 4 sprigs across the front will spread fast enough. It's beautiful when the sun hits it in the afternoon, a red color, have that box mounted under a window and the iresine almost touches the ground.

I'm open to new ideas and combos because I want to add a couple every year; they're easy to maintain.

Never thought of popppies, love those, but how about violas and pansies? If you set them where you want them the following year, they may self seed out of the box.