Most potting mixes have fertilizer already added to them, so you won’t need to worry about feeding your plants for the first three to four months. Once that fertilizer is used up, it’s time to add more. You can use any commercial fertilizer sold for houseplants.
Your choices are really a matter of personal preference. Some fertilizers are powders or liquids that you add to your watering can. Others are time-release pellets you incorporate into the potting mix. Some of these are considered organic, others are not. I’ve used a wide variety of products: liquid concentrates, powders, time-release pellets, fish emulsion—and even my homemade “worm tea” (the diluted run-off from my worm composting bins). It all works fine.
Mix your fertilizers according to the package directions. More is not better—you’ll burn your plants. I’ve found that mixing fertilizer at half-strength and applying it twice as often gives good results. If you notice white minerals accumulating on the plant’s container, run some water through the potting mix to flush out the build-up of fertilizer salts. Be sure to let the pot drain thoroughly afterwards.
If you live in an area that has significantly reduced hours of daylight in the winter, you might notice your plants aren’t growing much at that time of year. Follow the plants’ lead, and reduce or stop fertilizing for the season. When days grow longer and growth picks up, it’s time to restart your feeding routine. Everyone deserves a break now and then.
The biggest problem most people have with growing container plants is watering. Ideally, the potting soil for your plant should have equal amounts of air and water trapped between its particles. It should be moist but not soggy.
Most people realize that letting plants dry out is a bad idea (unless you’re growing cactus). However, too much water can also cause wilting. Frequently, a novice gardener will interpret the limp leaves to mean the plant is thirsty, and water more. This nearly always proves fatal. What has actually happened is that the roots have suffocated from a lack of air. Dead roots can’t absorb water, so the plant wilts.
More plants die from overwatering than from drought. Always check the soil first. You can stick your finger into the potting mix, or buy a simple water meter that indicates how wet your plant is. Or, if it isn’t too big and heavy, you can simply lift the pot. A well-watered pot is heavy. If your plant feels like a light-weight, it’s time to water.
How much water should you apply? I usually add water until it runs out the drain hole in the bottom of the pot and collects in the saucer. Wait a moment, then pour off the extra water. You don’t want the roots sitting in a puddle.
In spite of the persistence of this well-intentioned advice, please do not put ice cubes on your plants. How would you like ice water poured over you? Use water that is approximately air temperature. Too hot or too cold will shock the plant, and might even kill it.
One other note: if you have a water softener, save the softened water for washing. It has a high salt level that will burn tender roots. Use un-softened water on your plants.
If you really have a hard time remembering to water your plants, I urge you to consider growing succulents or cactus. Aloe vera (pictured above) is one plant that can withstand considerable drying out, and still flourish. It’s the same stuff you put on burns, so having a plant around can even come in useful.
Next week I’ll talk about containers and repotting.