poneytails palms is not a true palm,its proper name is beaucarnea recurvata, you can grow this outside providing winter dose not drop to more than10degres above freasing and in summer it rises to no more that 30 degrees, so containers, soil mix 2 parts lome 1 part peatmoss,and 2 parts sand , and put some gravel in the bottom for drainage, place in full sun to light shade, water every three weeks in the growing season and feed them once in that time, in winter only water them enough to stop the folige from wilting that will work about once during winter , they are very slow growing but if you knock a branch off they will sprout another one in about a month. enjoy.