Much has been published on foliar feeding. However, if you read the published information carefully (a tedious process), you will see that very little is based on experimental data. Much of it cites the experiments performed by Tukey in the 50's. Other than that, there is lots of speculation. The biggest unanswered question I had, and still have, is whether any of the experiments controlled for dripping of the foliar fertilizers onto the soil, resulting in root feeding as well as foliar feeding. Except for my own experiment, which did carefully control that, I was unable to find this mentioned in any of the experimental procedures. As with many gardening practices, psychology plays a big role. If foliar feeding brings a happy feeling to the gardener, maybe it's worth doing, whatever the effect on the plants. Jim

Nancy, I tried foliar spraying all my plants with a water soluble fertilizer today. I heated the water in the microwave before I sprayed them, and the mist coming from the sprayer was warm, but not hot. I, too, had read somewhere that plants are suppose to be able to take in a higher percentage of the nutrients through foliiar feeding than if you simply water the soil mixture of the plants, and that foliar feeding can be especially beneficial if the root system of the plant is weak. I may wait until warmer weather to try the fish emulsion foliar spray mix. I will probably want to be able to open a window or two when I apply that.

I only use foliage feeding for my micro nutrients. This paragraph gives a good detailed explanation of the only reason why I foliage feed. Research over many decades has explored the mineral uptake and transport of many species of fruit trees, conifers including pine and spruce species, and some hardwoods of ornamental or commercial value. Results have been mixed in many cases, with some species responding well to treatment and others remaining unaffected. Generally, the results suggest that foliar application of particular nutrients can be useful in crop production situations where soil conditions limit nutrient availability. For instance, alkaline soils do not readily release many metallic nutrients, especially iron and manganese. Zinc, copper, magnesium, molybdenum, boron, and calcium are other micronutrients required in small quantities that have been applied to foliage in an effort to relieve deficiencies and combat fruit disorders. Fruit, as adjacent tissue, can benefit from foliar spray. But this is a localized application that does not affect the trunk or roots � and therefore is not a solution to soil imbalances. In fact, researchers consistently state that foliar treatments are a specialized, temporary solution to leaf and fruit deficiencies in tree fruit production but will not solve larger soil management issues.

"Calcium Nitrate is a good source of calcium and nitrogen in ionic form when dissolved in water and can be applied as a foliar at the rate of 4 TBLS per gallon of water" This is terrible advice for tomatoes and sounds like it could have been taken from some article from a media communitions writer on SF Gate who doesn't know diddly squat about tomatoes. Even for withering leaf tips and margins caused specifically by calcium issues or BER for which there is likely an underlying cause and if there is a problem you don't settle it by running out turning your tomato plants into foie grassed goose liver. Giving more instant nitrogen is likely to hurt yield and makes vines at best. You really need to balance the plants diet better if these sort of calcium problems surface, and if you want calcium just add dolomitic lime ($4 for a 50 pound sack) mix a tablespoon of dolomitic lime crushed with a tablespoon of vinegar, then updiltued into a gallon of water, to the soil right away. To the soil alternately, a beneficial boost of bone meal (in moderation to keep phosphorus in balance) or Tomato-Tone -even better- as soon as you can fertilize next. Adding calcium nitrate as recommended by the quoted part, agree with lindalana, for heaven's sake can be unhealthy and cause more nutrient lockouts. If you go that route, at least use cal-mag 2 tablespoons per gallon maximum, but really less is better since the ratio of calcium and magnesium is more important than calcium itself. At these rates you are looking for trouble and foliar calcium nitrate or even calmag should be the very last resort (meaning almost never). Calcium chloride at a teaspoon per gallon is more effective in a foliar spray if going this route, but use distilled water you can buy from the supermarket for under a buck a gallon to make the spray and if you have high sodium in your irrigation water it wouldn't be recommended either. PC