Caring for Houseplants in Winter
By Bob Chapman
On one of those gloomy days when the faithful gardener is unable to get outdoors (even to pull those ever-present, pesky weeds!), consider grooming or repotting your houseplants.
GROOMING
Hot air furnaces can coat the leaves of houseplants with a fine, almost invisible, coating of dust, even in the well-kept house. Dust-covered leaves do not work correctly. The dust may inhibit the food-manufacturing function of the leaves, thus possibly causing the plant to weaken and not develop the stem and roots as it is supposed to do.
Wipe off each leaf, top and the undersides, with a soft clean cloth. While doing this important task, snip off any dead or diseased leaves.
Our thick and broad-leaved houseplants (for example, the Pothos, split-leafed Philodendron or Peperomia) can be polished, using a product sold for this purpose. This will make them glisten, brightening up the room. Please note that many of our favorite houseplants with thin leaves (for example the African violets, Fittonia or Plectranthus, the Swedish Ivy) can be harmed with the leaf polish, so carefully read and follow the directions on the container before using the product.
"BURNED" TIPS OR EDGES
Tips or edges of some houseplants display a brown edge to the tips or sides of the leaf.
Many of our thin-leafed beautiful houseplants suffer from "saltburn". They are particularly sensitive to excess salts in the soil. Harmful salts collect in the soil and are transported to the leaves of the houseplant. They accumulate at the tips, along the edges and, if severe enough, affect the entire leaf. The salts kill the cells one by one. These salts are in the soil, in the water we use, and are added with some fertilizers used to feed plants.
We need to get rid of these toxic salts before they kill the entire plant. Do this by flushing the soil thoroughly. Take the plant to the sink or outside. Run water through it two times. This will leach out most of the accumulated salts. On the third time add one half teaspoon of vinegar per quart of water and use this to flush the soil. The vinegar neutralizes the harmful salts and will lower the pH of the soil making it more acidic. It will help keep it salt-free
If the container is too large to handle, use a turkey baster to remove excess water from the saucer under the container as you flush the soil.
Use the vinegar/water solution instead of regular water every other week when watering salt-sensitive plants. Your houseplants will love it. The new growth will be nice and green and free of those burned tips and edges.
You can get rid of those unsightly "burned" edges of leaves by carefully trimming the brown portions away. Use sharp scissors and trim it to the same shape as a healthy leaf.
When using tap water, fill a wide-mouth container with water and let it sit overnight before using it on your plants. The chemicals added to purify the water will evaporate and they won't cause a buildup of toxic salts.
REPOTTING
Now is a perfect time to repot, or move up to a larger container, those houseplants that have been in the same sized pot for many years. Use OSH Potting Soil for most plants when transplanting. Use the special mixes developed and manufactured especially for African violets or cacti.
After removing the plant from its container look carefully at the roots. If they are thickly matted or appear to be encircling the perimeter of the root ball, consider trimming the roots before repotting. Use a sharp knife, a single-edged razor blade or a box cutter and in four equidistant places around the root ball, cut into the soil about one-eighth of an inch deep, no more, and sever the roots. This will cause new roots to form, growing into the new potting soil.
CHECKING THE MOISTURE
Hot air furnaces can dry out the soil of your plants in what seems a record time. Check them frequently for the moisture content. Use an inexpensive moisture meter, a wonderful, accurate device that measures the moisture content of the soil from the top on down to the lower depths. (Note: For a couple dollars more you can purchase a device that measures the moisture content, the pH of the soil and has an accurate light meter!)
Or use the "finger test." Insert your finger into the top of the soil and pull it out. If soil particles are clinging to your finger, the plant does not need watering at this time. Checking the moisture content of the soil will keep your houseplants alive and gracing your home with their beauty.