HEALTHY HOUSEPLANTS

By Linda C. DOLAK

OSU Extension master gardener volunteer

111A plant will absorb (soak up) only as much water as it needs. If too much water is added to a potted plant without drainage, it will accumulate in the potting soil. Eventually, the soil will become saturated and will replace the oxygen necessary for the growth of the plant. Eventually, the roots will die from lack of oxygen.

Do not saturate your plant. Don’t water your plants on a regular schedule. Instead, stick your finger into the potting soil about one inch. If the soil seems dry, it is time to water your plant. Add enough water until it begins to drain from the drainage holes in the bottom of the planter. Then empty the excess water from the saucer below your pot. If you are going to be away for a period of time, there are self-watering devices available at your favorite garden store.

Now that we know how to water, let’s discuss the type of water you should use. Not all water is the same, and not all water is good for your plants. Oftentimes, we just turn on the water faucet, and water our plants. Simple, huh? No, not quite as simple as that. First of all, if you are using tap water, it should be left out for 24 hours before use. This will allow the fluoride and chlorine to evaporate (escape into the air) before using the water on your plants. Fluoride may injure plants that have long, slender leaves, such as a spider plant. Brown leaf tips on the plant are usually caused by chemicals. If you are not sure if chlorine is in your water, smell the water. If it smells like chlorine, then let it set.

Many people these days have water softeners. These take the calcium and other hard-water nutrients out of your water, but also add salt (sodium). You may or may not be able to taste the salt, but your plants will know it’s there. Even though some plants need very small amounts of sodium, it’s toxic to most plants. The salt enters the plant, and as the water evaporates, it leaves behind higher concentrations of salt. Plants usually require small amounts of calcium and sodium, but the high levels in water softeners are damaging to plants.

There are potassium-based softeners that may cause fewer problems, but are still not good for your plants. Basically it is the same problem with a build-up of chemicals. Although plants actually use potassium as a nutrient, it will eventually lead to too much potassium.

If you are using reverse osmosis water, a process available with water softeners, be sure to include a micronutrient for your plants because this process removes chemicals that may benefit the plants.

So what can we do to have healthy plants? Letting the water set in a container for at least 24 hours also brings water to room temperature and avoids water that’s too cold or too warm, which will shock your plants. Another way to eliminate the buildup of chemicals is to frequently filter the chemicals by placing your plant in a sink and slowly pouring in water that has been setting out. That will basically “rinse” the chemicals from the planting medium (such as potting soil). Also, the plant can be repotted, using new potting soil, before any damage occurs.

To learn more about houseplant care, go to: http://go.osu.edu/careinside.