I guess I'd have to say it all depends on who you talk to. Those who use and advocate foliar feeding firmly believe in its benefits. With a caveat attached - when it is done properly.

And there lies one problem for those who call it hooey and hogwash. It often isn't done properly. In that case, at best the benefits are questionable and at worst it can be harmful to the plants. Another issue those who denounce it pose is that it cannot replace soil feeding/improvement. But foliar feeding advocates don't claim it replaces soil nutrient supplements and IMO that doesn't mean it has no role.

Many studies have been done as early as the 50s and 60s that prove that plants can and do absorb both water and nutrients via the leaves. So the real issue is (1) if the spray used provides nutrients in a form useable by the plant and (2) if they are applied in such a manner that they can be absorbed.

Kelp and molasses? Heard of it sure. Kelp suspensions are commonly used. Molasses much less so since its role is as a 'booster' for what ever it is mixed with, not as a primary.

So only you can decide for yourself if it is credible or its hooey. Try it and decide for yourself. Check out the article linked below.

Dave

Here is a link that might be useful: Foliar Fertilizing FAQ

Foliar feeding is used as a supplemental means of fertilizing, not the primary method.
It can be particularly useful for a mineral deficiency. Gets into the plant much faster than through the roots.

What does it mean? "Gets into the plant much faster than through the roots." How much faster is that? Seems to me that root feeding, with fertilizer or nutrients that are dissolved in water, should start to be adsorbed into the plant in a matter of minutes to hours. And, since this is the way that plants have apparently been "designed," it seems that this would be a pretty fast way to feed them. I'm not saying you might not get some adsorption through foliage, and that this might not happen almost immediately, but I just don't see how this can be much faster, or better, than through the roots.

Molasses brings a lot to the table whether used as a foliar or soil drench as the link will show.

http://wiki.answers.com/Q/How_does_molasses_make_plant_blooms_bigger

The other link addresses some of the above questions concerning foliar feeding and it benefits.

Here is a link that might be useful: Foliar Feeding

I consider foliar feed èpick me upè treatment. Yes, roots should be absorbing in a matter of minutes but sometimes they donôt... it could be newly transplanted plant, or whatever other reasons why roots are not able to do the job properly- could be many...

I had to see for myself, so I performed the experiment described in the link below.

Jim

Here is a link that might be useful: Foliar Feeding Experiment

It has been very handy this year having a direct route into the plant given all the rainy weather, slow root development, and overly wet soil.

Dave

I Think that foliar feeding is effective. Plants have ability to absorbs water/moisture through leaves. AND if there are nutrients DESOLVED in the water, they will be absorbed it, naturally. We know that herbicides like Round Up is absorbed through the leaves and then goes down to the roots and kills the plant. Some years ago, an older gardener told me that a herbicide is actually a VERY strong fertilizer(Nitrogen Solution ?) that burns the plants.

So, in conclusion, there is no doubt in my mind that foliar feeding works thou I may not be able to measure its amount and degree of effectiveness.

"Generally, ... foliar application of particular nutrients can be
useful in crop production situations where soil conditions limit nutrient availability."

From "The Myth of Foliar Feeding"
at
http://puyallup.wsu.edu/~linda%20chalker-scott/Horticultural%20Myths_files/Myths/Foliar%20feeding.pdf

Here is a link that might be useful: foliar ferts explained