For all those who want to do something good for their plants during daily watering, there are the liquid fertilizers which, depending on the design, offer general or special compositions for specific plants. So there is the liquid fertilizer for vegetables as well as for tomatoes and herbs, boxwood and many more. Who has many different plants, can also bring a universal fertilizer in the irrigation water, so as to do something good for all plants. The amount depends on what's on the pack. It should be noted, however, that on rainy days when you do not pour, the plant food is not given. This should then be compensated for the next watering.