INDOOR IVIES AND VINES

by Joelle Steele

It's not easy to generalize about the ivies we use because there are so many different kinds of plants that can be referred to as "ivies" or "vines." They have similar characteristics (they're green and they cascade!) but they have different maintenance needs. In this article, we will talk about four ivies which hail from as far away as Australia and the Solomon Islands and as close to the U.S. as Mexico, Central and South America: Cissus rhombifolia (grape ivy) and Cissus antarctica (kangaroo ivy); Philodendron; Scindapsus aureus a.k.a. Epipremnum aureum (golden pothos); and Syngonium podophyllus a.k.a. Nephthytis (arrowhead plant).

Cissus are woody, hardy plants. They can tolerate air conditioning very well and while they do best in natural light, they will perform quite well around 50fc. They should not be overwatered as their leaves will either become mottled or turn black. If they dry out you should stifle the urge to soak them as you will probably do more harm than good. Cissus are most often plagued by powdery mildew, mites, or mealy bug. As I have mentioned in past articles, your best prevention for these potential problems is to be very selective when you make your plant purchases.

Philodendrons, like cissus, can tolerate the air conditioning found in most offices. They can also tolerate extremely low lighting — as low as 15fc — and still maintain a pretty good appearance. To see them really flourish, try putting them in natural light around 150 to 200fc. Philos like to be moist but not wet, and they can tolerate drying out with less ill effects than our old faithful pothos. They are quite pest-resistant and are not particularly susceptible to diseases, but when they do become afflicted it is usually with one of several leaf spot diseases such as Erwinia chrysanthemi, Phytophthora, Xanthomonas dieffenbachiae, or Dactylaria humicola. The fact that many of these diseases originate in the greenhouse should alert you further to the importance of being a careful shopper.

Pothos is probably the plant that every technician learns about first. But, why do so few of them maintain that full, lush look they had when first installed? Maintenance! Pothos must be pinched back to stay full on top. That doesn't mean you have to cut off all the trailers, just one or two every few months. That way you'll always have new ones growing alongside the more mature vines. Pothos can tolerate low light levels but if it drops below about 40fc you may lose some of the variegation over time. They like to be evenly moist, but, like the cissus and philodendrons should not be wet. When watering pothos you should be careful not to sprinkle water on the leaves as they are very prone to leaf spots which occur when water droplets sit on the leaf in a cool air-conditioned room where they take all day or longer to dry out. The most common disease which attacks pothos is Erwinia carotovora commonly called "rapid decay." This is, again, greenhouse originated, so be not only selective about the plants themselves but about your grower as well.

Syngoniums rarely become mature enough in interiorscape installations to look like the ivy plants that they are. This is because the syngonium is not properly cared for and is replaced before it can ever grow its long, elegant stems that cascade over the sides of the planter. Like other ivies, syngoniums should be pinched back so that they do not become leggy, but they should be allowed a few opportunities to grow trailers and not remain so "shrubby." They are well suited to hydroculture and should be kept moist, particularly in warm rooms or in good light of 75fc or more. They will do well in low light down to about 40fc but be careful not to overwater them. Even if they are collapsed from underwater, just give them a regular watering and they will recover nicely. Like pothos, you should be careful not to drip water on the leaves of syngoniums as they will spot and become unsightly. They are prone to leaf spot diseases such as Xanthomonas vitians, Cephalosporium cinnamomeum, and Erwinia chrysanthemi.

Most leaf spot diseases which affect ivies are greenhouse-born and do not appear once installed as the humidity is usually too low for them to just "happen." Select your new foliage carefully. If, after the plant is installed, you find that it has a contagious leaf spot disease, remove the plant to avoid further contamination.