Grow your plants in containers that have drain holes. Then, no matter what type of plants you have, water them until the moisture seeps out those drain holes. Wait several minutes and toss out any extra water that might be left sitting in the tray or saucer beneath the pot.
Watering your houseplants
From eNews, March 9, 2006
How much water does my fern need? Does it need more than my jade plant? It can be very frustrating when the care label on the plants suggests "evenly moist." So how do you know when and how often to water your plants?
All houseplants are governed by their surroundings. The container, type of soil, temperature, and humidity levels in the house, and the amount of sun outside, all play a large role in how much water your plant needs. The first thing to look for when trying to gauge your watering frequency is drainage holes. You should water your plants until the water drips out the drainage holes. This helps flush excess salts and toxins from the soil, and it's proof that the soil is completely wet. Remember to toss out the excess water in the plant saucer.
Next, learn to feel the soil. When the soil feels dry to the touch, just below the surface, it's time to water. Another way to determine if your plants need water is to do the "lift" test, which uses the weight of lost water as an indicator of when you need to add more. Here is how to do the test: lift the flower pot right after watering and note its weight, then lift the pot again after a few days; it will feel lighter. With experience, you will learn how light you can let each plant get before it wilts.
The "Prairie Yard and Garden" show is produced by the University of Minnesota, Morris, Media Services Department and airs on Thursdays at 7:30 p.m. on Pioneer Public Television, channel 10 (KWCM) or 20 (KSMN). On March 9, U Extension educators Eleanor Burkett and Mary Blickendorfer will discuss "Shoreland Restoration and Revegetation;" on March 16, U horticulturist Mary Meyer will demonstrate the ways of "Dividing Perennials;" on March 23, master gardener Randee Hokanson will talk about "Fall Clean-up: Putting the Garden to Bed;" and on March 30, Extension horticulturist Bob Mugaas will present "New Ideas in Turf Management."
To learn more, see PYG online.
When watering, use only room-temperature water and avoid softened water, which has added salts that can build up in the soil.
The distinction between different houseplants is not in how they are watered but how often. Some plants, such as ferns or African violets, need attention as soon as the soil surface begins to feel dry. In contrast, cacti and succulents thrive when the soil is allowed to get quite dry between waterings--however, not bone dry.
Most plants fall somewhere between these two extremes. Allow soil to dry perhaps an inch or so below the surface, depending on pot size, before watering thoroughly again. The goal is to allow air to penetrate the soil, bringing needed oxygen to the roots. When soil stays wet too long, certain microorganisms can take over, rotting the plant's roots.