Scot, believe it or not, given my oft-stated belief that new transplants should not be fertilized, I did exactly what you propose once while working as a summer intern at a Forest Service nursery.

While things like red pine were the heavy hitters there, there was a block of black spruce that were off-color. The Sup. let me try spraying a product made here in WI called "Watch Us Grow" on a portion of that block. Sure enough, it greened them right up. Watch Us Grow is really just a fancy fertilizer, having all the macro nutrients plus every micro there is. I think there's a little something about the stuff that was designed to aid in foliar absorption though. Not sure if it was just a wetting agent, or if it went beyond that.

FWIW, that product is still sold and it is a decent all-purpose fertilizer.

+oM

If you decide to foliar feed, wait several weeks until the plant is more established. Then use a week solution. You need to make sure you dont burn the new seedlings. Something easy to do if your calculations are off. You are better off fertilizing more often with a weeker rate. Good Luck.

I'd go for osmocote.

Dax

Osmocote wouldn't work as a foliar treatment; it is a slow-release coated fertilizer.

I've got some Canaan fir seedlings that I foliar feed every two weeks with a 20-20-20 plus micronutrients soluble fertilizer. They look pretty good, growing much better than Fraser fir seedlings, which I have not been feeding. Of course, that's not really a fair trial - Canaan fir is purportedly more adaptable than Fraser fir. I fertilize seedlings in pots with foliar feed - I add about 1/2 teaspoon 20-20-20 per gallon of water, as well as 1 teaspoon of epsom salts, which apparently helps the uptake of nutrients. Later in the season, I'll probably switch to a low-nitrogen fertilizer like 4-18-38.

Am I crazy, or what?

Jim

Young seedlings must not be fertilized at all, it will make them lazy in making a good rooting system...

If you want the super-mix of media, have a look at what Rootmaker suggests. Bottom of the page "Ingredients For Success."

Dax

Here is a link that might be useful: Rootmaker

"Cool soils that are low in initial fertility are conducive to root-growth" -
this is why my seedlings and my recent transplants are not fertilized heavily at first.
As the seedling establishes new roots in the mix, I increase the fertilizer incrementally -
generally starting with a 1/4 strength dose and working up from there.

Foliar Feeding is inefficient for the most part, and really only benefits certain plants
at certain times of the season when growth is happening so quickly that the normal root-pathways
can't keep up with the demands of the plant. In other words, there is a very narrow window for
the practical and useful application of Foliar Nutrients. Not all plants have foliar pathways that
can even take up nutrients, nor are all nutrients in a form that can pass through those pathways.
Temperature, humidity, and time of day will also affect the nutrient uptake.

Fertilizing via root-pathways remains the most efficient means of nutrient delivery.

If the real issue with the plant is that the roots aren't taking up nutrients, then the root-issue
ought to be addressed. In containers, that issue most often has to do with a soil/mix that does not
allow for proper watering and drainage. Once the soil-mix is sorted out, root-health and nutrient
uptake shouldn't be an issue.

Josh

Tried it this morning. It may be my imagination, but several of the seedlings did seem to have better color this evening. Will try it for 30 days and then report back.

How old are your seedlings?

30 to 120 days. Arizona Cypress, rough-bark and Italian Cypress.

I would wait until your seedlings are at least 2" tall before fertilizing. If you feel like your seedlings are starving, give them a VERY weak rate and water before and after. I am affraid you will burn your little seedlings. When you do foliar feed, water before so they will be protected.