Tree ferns aren't so much trees as they are tall ferns with slender, woody trunks. They can grow up to about 20 feet with long, fronds and sprout perennially. These characteristics make tree ferns perfect additions to gardens and landscapes, especially if you want an exotic or tropical look. Since ferns grow in many different climates, almost any gardener can use tree ferns to achieve this look. Gardeners in areas with extreme winters should protect their fern trees in winter by covering their crowns with straw. Watering, however, is the most important aspect of fern tree care. A properly watered fern will thrive in your garden.
Pour your water into a water purification system before watering your ferns. Chlorine and other impurities may harm them over time, according to online resource Ferntastic. You can construct your own system with activated charcoal and sand or purchase one specifically for outdoor watering at a gardening supply store.
Adjust the sprayer nozzle on your garden hose to shower and aim the stream up over your fern tree so the water trickles down the tree's trunk from the crown. Water until the ground around the fern tree moist but not soaked. When the tree is young, stand several feet from it on the ground for the proper angle. As it grows taller, set an A-frame ladder several feet back from the tree so you can better reach the crown.
Water your tree fern once a week throughout the growing season and through the early part of the fall. Water every three days or so during drought. Spray the trunk on very hot days and every day during drought. Make sure the trunk is completely wet.
If you have overwatered your ferns, the fronds will start to go brown or even black in patches, according to Ferntastic. If the crown is still healthy, stop watering and the plant should recover.