Can I Plant My Split-Leaf Philodendron Outside?

Split-leaf philodendrons (​Philodendron bipinnatifidum​) are also known as tree philodendrons, which gives a good notion of the size of the plant. It hails from the tropical rain forests of South America and is an imposing foliage plant outdoors, growing to 15 feet tall with a 10-foot spread. You'll need to live in a warm, humid area to have one thrive in your garden. More often, split-leaf philodendrons are sold as houseplants in the United States.

The split-leaf philodendron is a large plant with huge dark-green leaves with deeply split edges. Even when grown as a houseplant, the leaves can be 12 to 24 inches across. If this makes you think of the extremely popular Monstera houseplant (​Monstera deliciosa​), you are not alone since many people (and websites that should know better) report that the two are the same plant.

This is not the case, although both are tropical rain forest plants. How do you tell them apart? ​Monstera deliciosa​ has leaves with perforations inside the leaf; the slices do not reach the leaf's edges.

Those in mild climates may consider growing split-leaf philodendron plants in the garden. The plant can thrive outdoors in U.S. Department of Agriculture plant hardiness zones 9 through 11. However, the split-leaf philodendron prefers a humid environment where the temperature doesn't drop below 55 degrees Fahrenheit. The ideal temperature range for these philodendrons is between 64 and 77 F.

This means that only gardeners in USDA zones 9 through 11 should attempt growing the split-leaf philodendron outdoors, but there are no guarantees. These are high-humidity tropical plants, and they won't be happy in hot, dry areas. Even in moist, mild areas, the plants won't be happy if the temperature plunges one night.

Warmth and humidity aside, the split-leaf philodendron has a few other cultural requirements. These are similar for outdoor or indoor plants and must be met to keep the philodendron vibrant and healthy. Remember that the tree philodendron can grow to 15 feet tall, so select a site where it isn't cramped.

Split-leaf philodendrons also need light — and lots of it — to thrive. Low light conditions lead to stunted or leggy growth. However, don't plant them in a site where the sun shines directly on their leaves, or they may crisp and brown. Dappled sun or bright, indirect sun is the ticket. Give the philodendron fast-draining soil and don't let it get too dry or the plant will die. Don't overwater the plant or you risk yellowing leaves. Irrigate only when the soil is dry to an inch or more.