Feeding Houseplants Growing in Water
Although plants get some important elements from the air, they draw most of their nutrients through their roots. For those grown in hydroponic plant environments, it’s up to us to provide fertilizer in the water. If you’re serious about creating hydroponic plant environments, it’s a good idea to have your water tested before you begin. Often, water contains a significant amount of calcium, magnesium, sodium, and chloride, and in some cases, may contain excessive amounts of boron and manganese. On the other hand, iron, potassium, phosphorus, nitrogen, and certain micronutrients may be lacking. A water test reveals exactly what your water needs in order for plants to flourish. As a general rule, however, feeding houseplants growing in water isn’t that complicated and, unless you’re a chemistry buff, there’s really no need to stress over a complicated formulation of nutrients.
How to Fertilize Plants in Water
Simply add a good quality, water-soluble fertilizer to the container every time you change the water – usually every four to six weeks, or sooner if half of the water has evaporated. Use a weak solution consisting of one-quarter the strength recommended on the fertilizer container. If your plants are looking a little puny or if the foliage is pale, you can mist the leaves with a weak fertilizer solution weekly. For best results, use bottled spring water, rainwater, or well water, as city water tends to be heavily chlorinated and devoid of most natural nutrients.