Volume 14, Issue 3 ~ January 19 - 25, 2006

The Bay Gardener

By Dr. Frank Gouin

How to Water Your Houseplants

Not too little and not too much

Houseplants need water, but how much? More house plants are killed by improper watering than by any other practice.

Fault 1: Surface watering

If you add only enough water to wet the surface of the soil, the soil in the middle and at the bottom of the pot will be as dry as the Sahara dessert.

Remedy: Add sufficient water so that 5 to 10 percent of what you add drains through the bottom of the pot. What about water flowing on to the table or windowsill? Isn’t that what saucers are made for?

Fault 2: Poor drainage

Consider the plant potted in a glazed pot with only one pea-sized drainage hole in the bottom. Do you think that placing a few stones in the bottom of the pot will solve the drainage problem? What happens when the void between the stones fills with water and the pea-size hole becomes plugged with rooting medium?

Remedy: Before watering, test each plant’s soil to see if it is already wet lest the rooting medium becomes saturated and the roots drown.

Lesson: Roots need both air and water. Too much water will cause them to die and rot, while not enough water will cause them to dehydrate. The ideal moisture conditions for growing plants are uniformly moist throughout the rooting medium. This means using a good rooting medium that is rich in organic matter, checking the soil to see if it is dry before applying water and adding sufficient water so that an excess drains through the bottom of each container.

Amaryllis, the Second Time Around

Q Remind me again, please, how to bring an amaryllis to bloom a second year. After its first bloom, it summered outdoors in its pot, and I watered it with the rest of my potted plants. The leaves eventually yellowed. When frost threatened, I brought it indoors still potted and set it on a windowsill, where it still sits, a nice fat bulb but no shoot. Should I water it? Should I feed it? Should I throw it out?

—Sandra Martin, Bay Weekly editor

A Stop watering an amaryllis after the leaves turn yellow; otherwise, it will rot. That’s not your problem, however. Instead, you allowed the soil around the bulb to go dry. Amaryllis need dry, dark dormancy. Unpot the bulb, shake off the soil and put it in the dark until about Ash Wednesday. When you see the shoot start growing, repot it and put it in the light. When you repot, bury only one-third of the bulb in the soil; leave two-thirds exposed. Water it well but not every day. Let the soil dry between waterings.

Ask Dr. Gouin your questions at frgouin@erols.com. All questions will appear in Bay Weekly. Please include your name and address.

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