thanks for your response. agreed- for a while i was planning to incorporate new tiles as i added them, but i've decided to keep versions separate so as not to mangle people's creations. so i've reverted the version at vacuumflowers.com/gardener to the original tileset, and the next version will be at a separate url.
it will always be possible to take your save files from an older editor and open them in a new one (and then manually tweak whatever is necessary due to changes between versions)
i hope that makes dealing with a pre-beta tool more pleasant and predictable.