Question
How often should I fertilize my house plants, and window boxes, and what is the best type of fertilizer to use? I recently purchased some liquid fertilizer (some sort of seaweed extract or something) that I added to the water when I watered my plants, and I'm not sure it is having any effect

Answer
If you use liquid fertilizers (always follow dosing on the lable) apply it every 14 days - a bit less during the winter. Some plants are heavier feeders than others and I would recommend that you research the nutritional needs of the individual plants. Using liquid fertilizers according to the 'light' application on the lable and then applying more often is safer than a a heavy dose once in a while.

Symptomes of lack of fertilizer is usually light green leaves (turning from green to yellow), stunted growth, no flowering. Symptomes of too much fertilizer is typically a noticable curl on the leaves which are becomming small but very dark green. brown leaf tips are also typically from too much fertilizer, but can also be from too much water or too little water.

Always follow dosing information on the fertilizer lable.