Are Philodendrons Perennials in Zone 8?
- Three options exist for gardeners wanting to grow healthy philodendrons in Zone 8. The first and safest way is as a houseplant, so plants never experience frost. A second option is to grow philodendron plants in containers and relocate them outdoors to bask in the rains, humidity and warmth of summer and then place them back indoors over winter. Lastly, since philodendrons grow quickly, gardeners can plant them outdoors in spring after threat of frost and let them proliferate and expect them to die once fall frosts occur.
- It's possible that some philodendron plants may survive the winter in Zone 8, especially if in a warm, sheltered outdoor location. If the stem base or roots do not freeze, it's possible a plant will rejuvenate in spring once temperatures warm considerably. Overwintering is most likely to occur only in the warmest parts of Zone 8, sometimes referred to as Zone 8b, where lows only drop to the 15 to 20 degrees Fahrenheit range. Placing philodendrons on the south or southwest side of a wall or foundation may help plants survive the winter, but is not a guarantee.
- Perhaps the most cold-tolerant species is the cutleaf or split-leaf philodendron (Philodendron bipinnatifidum), also called selloum. While most reliably hardy in USDA Zone 9, if winter cold isn't too severe or of long duration in Zone 8, this species can grow as a perennial. Subfreezing temperatures kill back the leaves and stem as far as the ground. If the roots don't freeze, new leaves emerge in spring. To ensure the lowest stem parts and roots don't freeze in Zone 8, cover the plant with 12 inches of mulch to insulate it. After the threat of hard frost passes in March, remove the mulch so the soil warms and the plant regrows.
- Much like with hardy palms or taro, philodendrons grown in Zone 8 may survive winter better if their roots are not saturated in wet, soggy soil. While it's important the soil must not become bone dry and cause roots to shrivel up and die, too-wet soil and subfreezing temperatures cause the roots to quickly rot. The protective mulch layer may keep the roots from freezing and prevent winter rains from saturating the soil. Check on the dormant plant in winter to water it as needed, pulling back and replacing the mulch after monitoring the soil moisture.
