Here's an idea - put some tangible 'value' in the pledge the students are taking - ask the kids to pony up 25 cents for their bulb; bulbs shouldn't cost more than that. For those who are unable to pay; your school council already has a slush fund of 200 bulbs to cover this anticipated occurrence. I remember as a kid, I valued my things that I tangibly had to pay for; verses things simply handed to me. But perhaps I'm just an odd ball and kids minds don't work that way anymore. It seems like kids are handed so much without much thought to earning it themselves or saving for something of value - this worries me. Just an idea. Good luck with your venture.

How good of you to take on this task! Do you have the kids help? (that can be fun too, to run it as an after school activity.) If there are flat rocks in your area, you could collect some (or alternatively keep an eye out on Craigslist for free used bricks) and use them set hozontally along the edge of the paving as deep as seems necessary (sort of widening the paving.) Leave a couple inches of spacing between the rocks and plant between the rocks with plants that can crawl onto them. That way there would be a sort of transition zone of plants that would survive being walked on since the roots would be protected, but also give a bit of warning to the kids that they were off the standard paving. The rocks or bricks will keep the plow from dropping down into the dirt and uprooting the plants and being flat shouldn't pose too much of a problem for the plow (or at least that's my experience since the plow went right over my flat brick edging a few years.) Wooly thyme doesn't seem to flower much in my garden, so might work. Some of the shorter Carex (sedges) may work, especially variegated ones like 'Ice Dance.' Astilbe chinensis 'Pumila' grows low and spreads, but flowers in August and doesn't seem to draw bees. Lady's mantle has such subtle flowers that no one will probably notice them, and has both a larger variety and a smaller one. You could also use some shrubby low groundcovers like Paxistma canbyi (no flowers usually), cranberry (tiny flowers), bearberry (Arctostaphylos) or one of the low growing winter heaths or heathers if your soil is a bit acidic. Many heathers have colorful foliage. Just check the flowering time of your particular cultivar and be sure it is during the summer. The shrubby plants you would have to plant back from the sidewalk far enough that the plow and kids won't mangle the center of growth and so that it won't grow onto the sidewalk. I don't know the salt tolerance of most of these since I don't salt the walk, but I do know that heaths and heathers seem to be pretty salt tolerant. As far as the budget . . . Once you decide on your groundcover, if it is one of the more common ones, you can check with the principal about sending home a request for donations of that type of plant. S/he may be supportive of this.

tibouchina is beautiful but not especially drought tolerant and can get rather large for your sight (8'wide and tall) you might consider sub shrubs like lavender, rosemary, santalina, some of the smaller varigated new zealand flax, bottle brush, wooly blue curls (trichostema lanatum), leptospermum, coast rosemary (westringia), and dietes (fortnight lily).

Tibbrix, You are not afraid of color, are you? I am homeschooling my younger two boys, ages 11 and 14 (plus I have a 16 year old son who uses the space) so I'd like it to be a sort of masculine looking but fun space. I thought more about the green posted above but what I like about this room is that it has a good amount of light, unlike the rest of my house. I'm afraid a darker color would suck the light out of the room. We have a small room downstairs that is a dark mossy green, and the room is just so dark. This room is much bigger so though so maybe it would be ok? I'm thinking about Behr crisp celery. I'm not sure how to post the picture I found but I posted the link below. Here is a link that might be useful: crisp celery