Improper watering is No. 1 killer of houseplants

Source: David Trinklein

COLUMBIA, Mo. - Improper watering is probably the biggest killer of houseplants, said a University of Missouri Extension horticulturist.

No single watering schedule is appropriate for all houseplants, said David Trinklein. Plant size, pot volume, light, temperature, humidity and other conditions influence how quickly the soil will dry out.

"Soil kept either too wet or too dry kills the plant roots," he said.

In general, flowering plants need more water than foliage plants of the same size, he said. Never allow plants to wilt and never allow them to stand in water for long periods.

Learn to gauge the moisture content of the soil by its color and feel. As the soil dries, it becomes lighter. Under continued drying, the soil begins to crack and pull away from the sides of the pot.

Soil kept too moist becomes sticky and slimy, inviting root rots and other diseases.

Ordinary tap or well water is usually satisfactory for plants. Chlorine or fluoride added to city water does not harm plants, he said.

Rainwater and melted snow are excellent. Water run through most water softeners should not be used continuously for potted plants.

You can water from the top or the bottom of the plant. If you water from the top, use a watering can with a small spout and keep as much water off the foliage as possible. Wet the entire soil, not just the top inch.

Add water until it comes through the drainage hole in the bottom of the pot. Discard water that remains beneath the pot one hour after watering.

Watering from the bottom ensures thorough wetting of the soil mass. Place the pot in a pan or saucer filled with water or dunk the pot in a bucket of water just below the rim of the pot. When the top of the soil becomes moist, the entire soil ball should be wet. Remove the pot, allow it to drain and return it to the saucer.

Salts may form a white accumulation on the soil surface if you regularly water plants from the bottom. Occasional watering from the top helps wash out the salts. When doing so, discard water that drains out of the pot to prevent the soil from reabsorbing it.

If surface salt accumulation becomes too heavy to remove in this way, scrape off the surface soil and replace it with fresh soil.

Visit the Garden's Edge store in Jackson and purchase your moisture meter to help determine the moisture content of the soil in your plants.