Lily trees are a relatively recent trademarked form of lily, which are actually Oriental hybrids. These lily trees can reach heights of 6-8 feet, as can many other hybrid Orientals can. However, if you have purchased a lily tree, the most popular cultivars being "Boogie Woogie" and "Satisfaction," there is no need to think that these hybrids need any special care other than that you would normally give any other type of Oriental lily. Planting these bulbs is also no different than how you would plant other types of lilies.
Choose an appropriate planting site. Tree lilies, like all other lilies, prefer full sun. In warmer climates (zone 5 or warmer), you can choose a site that provides your lilies with some protection from the hot afternoon sun.
Dig a planting hole. Tree lilies, which tend to have larger bulbs than most lilies, should be planted at least 10-12 inches deep. If you are unsure about the depth, place the bulb in the hole. Hold your open hand in the hole with the ends of your fingers touching the top of the bulb. The top of the planting hole should be at your wrist.
Work some organic matter into the planting hole. All lilies like good drainage. To insure that your tree lily gets this drainage, just work in 2-3 handfuls of some type of organic matter, e.g., compost, dead leaves, sand, or peat moss.
Fertilize. Once you have covered the planting hole and your tree lily bulb, apply a time-released balanced fertilizer. This can be found at any garden center, and you need only follow the directions on the back of the bag.
After you have applied the fertilizer, cover the site with 2-3 inches of any type of organic mulch.
Water your tree lily well. Set your sprinkler to water the site for at least 20 minutes.