Garden Q&A: What is this fern-like plant?
Q: I noticed a plant in my woods that had fern-like leaves with different shades of green in a distinct pattern. I don’t notice them in the summer, though, just in early spring. Is this something that can be grown in a shady garden?
A: You’re probably seeing Eastern waterleaf (Hydrophyllum virginianum), a native perennial in the borage family named for its water-marked leaves. There are silvery splashes in the leaf center, and the edges might even be blushed with reddish-purple. This attractive pattern is absent or muted by summer when foliage becomes more-or-less solid green. They’re probably still in your woods at that point, just blending in with the medley of other green foliage. White blooms appear around May.
In March, as fresh leaves are emerging for the season, it’s a showstopper. I wish they were more widely grown since they could be a native analog to Japanese painted fern with regard to garden design, but they’re comparatively scarce at nurseries for some reason. Since wild plants spread from rhizomes as well as seeds, you may be able to propagate more from seed to grow in a woodland-style garden. Growth might be aggressive, which can be an asset if you’re trying to keep annual weeds like Japanese Stiltgrass at bay in the garden.
Q: How do I keep an indoor palm happy? I often see them with browning leaf tips and want to avoid that if I try one myself.
A: As a generalization, when compared to other common houseplants, palms are hard to grow well indoors. The group is diverse, though, and some species are more tolerant of less-than-ideal conditions than others. It helps to know what kind of palm you have, though I grant you that houseplant ID tags are often lacking in such details. Commonly grown palm types include areca, lady, kentia, parlor, and fishtail. Clemson Cooperative Extension provides some basic care information particular to each palm type on their Indoor Palms web page.
Overall, give palms bright light (direct sun would be great), mild to warm temperatures, and high humidity. Dry indoor air stresses many houseplants, but a room humidifier can help. Let the top inch or so of the potting mix get somewhat dry before watering, but don’t let the pot dry out too thoroughly or allow it to stay constantly wet. If a pot sits atop a saucer or inside another pot without a drain hole, make sure that gets emptied promptly after watering so the roots don’t stay soggy.
Palms can do fairly well if grown in the same pot size for years at a time, though the potting mix itself might need refreshing to avoid salt (excess mineral) buildup from tap water or unused fertilizer residues. This is no different than the care for other indoor plants, but because palms are quite tolerant of being pot-bound for a while, gardeners may forget that the potting mix is deteriorating over time and should be refreshed periodically. Potting mixes geared for cacti and succulents, or anything using ingredients that maintain good drainage, are helpful to avoid overwatering. When repotting, take care to keep the planting depth the same, as palms are not tolerant of being planted too deeply, even by a couple of inches.
When leaf yellowing, spotting, or browning occurs, there could be several causes. Low humidity or over-fertilization may damage leaves or encourage a population boom of spider mites that stipple the foliage. Mites can be hosed off the foliage outdoors on a warm winter day or in a shower stall. Nutrient deficiencies can be another factor, such as potassium (K); when unavailable to roots, plants pull potassium out of the oldest fronds to recycle it for younger growth. As a result, those lower, outer leaves can develop translucent yellow spotting or brown tips as they die back.
Too little light can cause frond loss, as will the natural aging-out of foliage over time, and this will also affect the oldest leaves first. How do you tell the difference between normal leaf shedding and that caused by potassium deficiency? According to University of Florida Extension, palm leaves dying off from a deficiency will retain a green rachis (the center “midrib” running down the middle of the frond) while the leaflets die back, and they will take a long time to fully die off and fall. In comparison, routine old-age or low-light frond shedding will turn the frond with its rachis uniformly brown and it will fall off comparatively quickly.
Florida’s fertilization recommendation for container-grown palms is an N-P-K analysis ratio of about 3-1-2, though 2-1-3 is probably also suitable since that’s the ratio they suggest for palms grown in the ground. Using a fertilizer that contains micronutrients – trace elements like magnesium (Mg), manganese (Mn), iron (Fe), and Boron (B) – at least occasionally, will help avoid deficiencies in those elements as well. Not all fertilizers formulated for indoor plants contain nutrients beyond the big three of nitrogen, potassium, and phosphorus.
During the growing season of late spring through early autumn, palms would enjoy spending their time outside. Start with semi-shade when moving them out, then gradually give them more sun, though full sun is not necessary. Acclimate them to more shade as the season winds down in preparation for bringing them back in. A summer outside will improve plant vigor and let them store more energy to sustain them during the lower-light, short-day season indoors.
University of Maryland Extension’s Home and Garden Information Center offers free gardening and pest information at extension.umd.edu/hgic. Click “Ask Extension” to send questions and photos.