great ideas, there. a neighbor had i believe a calla lilly - and it was looking good the last time i looked. i'm not sure if you can miss watering them, though.
cmg, surpringly - in the retaining wall behind where i live i had planted some tomatoes and basil, potatoes, carrots, etc. the year before. well, i went to pick weeds this year - and i almost fell over. someone HAD planted some marijuana amongst the weeds. not about to be accused of planting it - i pulled them all up. bad, i know -for whoever planted them. probably some kids. somehow - when you hear nowdays (what children weren't told 20 years ago) that sustained marijuana use can actually cause certain psychosis.
i suppose whomever planted them may be disappointed when they go to collect the weed.
pianowolfi, african daisies will withstand more that 1-2 days without water. just in case you travel.