Question: You’ve discussed the “wicking method” for watering plants before. Besides using a “lighter” soil, should I change how my violets are fertilized?
Answer: Yes. Unlike watering from the top, or by saucer, at regular intervals, the soil is nearly always moist when wick watered. Though a wicked plant won’t require any more nutrients, a greater volume of water passes through the soil, since it never experiences a “dry” period (much of it simply evaporates). As a result, there is greater danger of fertilizer buildup within the soil. To avoid this, less fertilizer needs to be added to the water when wick-watering. For plants that we have wicked, we’ve found that using fertilizer at 1/2 the normal dilution was sufficient. For example, 1/8 tsp. rather than 1/4 tsp. per gallon, the latter dilution being that used when top watering.
Another consideration when selecting a fertilizer to use for wicking is its water solubility. We’ve found that some powdered fertilizers can accumulate on the wick and clog it, if the wick is ever allowed to dry. If you experience a similar problem, a balanced, liquid fertilizer may be appropriate