Is melted snow good for watering houseplants? Don Kinzler answers that question and more in this week's Fielding Questions
In this week's Fielding Questions, Don Kinzler answers questions about orchids blooming in the winter, the cause of holes in potatoes, and whether melted snow is better than tap water for houseplants.
Q: I’ve had an orchid question for a few years. I have two Phalaenopsis orchids that usually start sending out flower shoots in October, which seems so strange. Light is getting shorter and their environment is cooler in weeks to come. Both plants sit in a south bay window, but this time of year it’s still cooler there than in the other seasons. Is it common for them to start flowering in fall and winter? Attached is a photo of the flowers that started opening on Christmas Day. – Roxanne L.
A: Thanks for the great photo, which is heartwarming on a cold January day. Phalaenopsis orchids reward their owners with months of bloom each year, and their care isn’t difficult, once you get the hang of it.
Yes, it is common for these orchids to develop their flowering stems in fall and winter. One of the recommendations for a Phalaenopsis orchid that refuses to bloom is to move it to a cooler location, such as the microclimate of a cooler window, because the reduced temperatures can trigger flower stalk formation. A flowering stem is also emerging on our own orchid.
Your orchids are following what seems to be their natural cycle. In the Upper Midwest, when windows get cooler, flower buds are commonly induced on Christmas cactus, orchids, and other plants whose flowering is coaxed by cooler temps, also accompanied by shorter day length.
Q: In my garden I raise 150 potato plants, spaced about 18” apart. I have never had a problem with potato bugs, which confounds me, but I do have some type of creature that “eats” at the potatoes as they form, boring holes roughly the size of a thumbnail in the potatoes. I can cut these areas out and use the potatoes, but they’re unappealing. I grow mostly Yukon Gold, russets, etc. I never see any worms or insects when digging potatoes. Can you help me stop this problem? – George B.
A: I'm glad to hear you haven't been bothered with potato bugs, also known as Colorado potato beetle, as they can quickly defoliate plants and are resistant to most insecticides. The current best product is Spinosad, which is quite effective.
There are three common causes of holes in potato tubers. First, voles gnaw irregular, roughly circular patches out of the tuber, often with teeth gnawing visible. They are often sneaky enough to go undetected until damage is seen. Rodent baits at the end of rows can be effective, or rodent traps baited with peanuts.
Second, slugs create holes in tubers, and the holes are neater in appearance than vole damage. To see if slugs are working in the area, place a board or cardboard on the soil near the potato plants, after first wetting the soil. Slugs congregate in cool, dark, moist places during the day, and crawl to their feeding sites at night. If you check under the board during the day, you can detect whether there's a heavy slug infestation.
Wireworms also create neat circular holes that extend into the tuber. Look for insecticides labeled for wireworms, that can be applied to the soil.
Q: Is it true that melted snow is good for watering houseplants? – Cindy M.
A: One of my wintertime jobs as a boy was to keep pails filled with snow on the heating radiators in our house. My mom then used the melted snow water for her houseplants, once the water warmed to room temperature. Her plants thrived with rainwater in summer and snow water in winter, which she much preferred to the “city water,” that was highly chlorinated.
Most sources do indicate that both melted snow and rainwater are healthy alternatives to municipal or well water sources.