Tips for Winter Houseplants
More houseplants are killed by improper watering than by any other practice. Here are three faults to avoid in growing indoor plants year-round or over winter.
Fault 1: Too little water
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 five to 10 percent of what you add drains through the bottom of the pot. What about water flowing onto 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 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.
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.
Fault 3: Ring around the pot
If you habitually irrigate a potted plant from the bottom, capillary movement of water moves fertilizers toward the surface of the rooting medium. As the water evaporates from the surface, it leaves behind fertilizer salts. In a porous clay pot, the water containing the fertilizer salts migrates to the top edge of the pot. When the water evaporates, it leaves behind a residue of fertilizer salts.
The accumulation of salts on the edge of the pot can become strong enough to burn the tissues on the stem of the leaves, causing them to wilt and eventually die.
Remedy: Repot in a clean pot. Switch your watering habits to irrigating the plant from the top at least twice monthly. Water poured in from the top forces the salts back down toward the bottom of the root ball.