Is the soil missing minerals? Is it low on N P or K?
I doubt it, especially if you are growing roses successfully. Trees generally do not need to be fertilized. So many fertilizer miracle pitches out there, and so little need for fertilizer accept for vegetables and flowers. It is almost never the case when a tree is not looking good or growing that the reason is lack of fertilizer, or other minerals.

The only Japanese maples I have ever fertilized are those grown in containers. Inground established trees seldom need supplementing, especially if you use a good organic mulch.

If you do determine a need to fertilize (and a soil test would confirm any need), I would not use a water soluble synthetic but rather a granular organic fertilzer. Fox Farms makes a fertilizer specifically formulated for the needs of Japanese maples under its Peace of Mind label. It is an excellent product.

Not that I am an expert, but I agree with IpmMan and gardengal48 that trees and shrubs grown in the ground should not need any supplemental fertilizer - unless you have had a soil test done and it came back showing deficiencies. Then you just need to supply what the test said is missing.

From what I have read, the Dyna-Gro Foliage-Pro is wonderful for container plants, including trees, but, as gardengal stated, it is best to use organic fertilizers, if needed, for in ground plants. You really don't want to pollute your soil with synthetics!

Holly

Fertilizing JMs can lead to a host of problems. Highly fertilized plants are more prone to disease and insect damage, and from winter damage on recent growth. They do best with no fert and only a dressing of compost added each year. Their form and color develop best this way, not "pushed" into growth with high-nitrogen artificial fertilizers.

But it is okay to push them with high Nitrogen organic fertilizer.
Besides the amount, not the synthetic/organic label, is what causes the amount of nitrogen.
Regardless of the type of fertilizer you use, you should have a soil test done & do not over do the N-P-K.
Azomite is good for the 17 mineral elements.

Here is a link that might be useful: Good & organic

Kaitain is right as far as my experiences go.
Years ago I 'pushed' some of my Japanese Maples with fertilizer. The new growth sent out long shoots of tender growth which were promptly colonized with aphids. They disfigured the end of the branches before natural predators took care of the problem.
I haven't fertilized since, and haven't had the problem since, even though the soil has been greatly organically improved.

Lesson learned.

In a pot, is a whole different matter. Unless you get the mix, pot size, water, location, and fert just right, it's an uphill battle. A real learning experience. Think marriage and diapers.
Mike

No, it is not OK to 'push' them with a high nitrogen fertilizer, organic or not :-) They simply do not require it and as both Mike and kaitain have stated, it can lead to excessive, lush growth that is more prone to insects, disease and drought.

Mulching the root zone each season with compost, keeping it away from the trunk, will replenish any needed organic matter and provide the tree with all the nutrients it requires.

And to clarify further, we are talking about inground planting here - growing JM's in containers is a whole 'nother kettle of fish and is approached much differently:-)

What, if any fertilizing a plant needs depends on what the mineral content is of the soil it is planted in. Trees and shrubs can need fertilizing just as much as non-woody plants, obviously nutrient deficient woody specimens are very common in my area (where a nitrogen deficiency is the one most likely to be occurring). Large swathes of the Midwestern and Eastern states have terrible soil nutrient deficiencies.

Sappy growth that is prone to infestation or disease appearing on maples or any other woody plants after nitrogen fertilization is the result of applying too much nitrogen, and not the use of nitrogen per se. In every case where fertilization is indicated the right amount needs to be applied in order to get the desired result.

Over fertilization is the problem. Fall and spring fertilization is fine. Just follow directions. Trees get from lawn fertilization so no need to apply "tree" types.

Organic program where you improve nutrient cycling will provide extra N-P-K plus minors. Organic fertilizer and others are supposed to support it by feeding soil biology. Cheaper than compost in large scale.

Tress that evidence nutrient deficiencies are usually those in gardens that receive minimal attention in the way of routine maintenance. Regular mulching with any sort of good organic mulch is usually sufficient to replace needed organic matter to the soil, which is a primary source of nitrogen.

That is not to say a tree will never need to be fertilized. But if one has taken care to amend and enrich indigenous garden soil overall before planting or starting a garden and continue to supply organic matter in the form of mulch (shredded leaves, compost, composted manures, grass clippings, etc.), additional fertilization is not often needed. Obviously, if a tree or any other plant is struggling or showing obvious signs of nutrient issues and other causes are ruled out, a soil test should be done to determine what is lacking and should be supplied.

Trees planted in lawns - and not all are...many are located in separate, dedicated planting beds - can often suffer from nutrient issues simply because lawns/turf grasses are highly competitive plants that grab all available nutrients. Fertilizing the lawn can help but can also cause other issues (outlined above) as most lawn ferts are high nitrogen products.

Regardless, if fertilizing IS needed, water soluble ferts are not the best method for trees or most other landscape plants. Most are synthetic in formulation and deliver a fast but not long lasting dose of whatever nutrient base they include. And because they tend to be applied to foliage and/or just the immediate base of the plant, they are not efficient in delivering the goods to where they are most needed - throughout the root zone. A granular formulation applied throughout the root zone is more efficient in this regard. You have a choice between a synthetic/manufactured fert or an organically based one - I prefer the organic because it delivers nutrients over an extended period, encourages beneficial soil organisms and tend to have minimal issues with regards to both burning/over-applying or with leaching into groundwater.

Digging in organics or mulching with them does not categorically eliminate or prevent a nitrogen or any other nutrient deficiency. There are too many variables involved. Sweeping add organics and everything will be taken care of style statements do not hold up to scientific investigation.

Slow release synthetic chemical fertilizers have been used in large scale nursery stock production for years.

Sorry, but I am going to disagree. Understanding soil biology and how organic matter cycles through the soil system clearly establishes the benefit of routinely replenishing organic matter to the soil as a primary source of plant nutrients, nitrogen being the primary player. The 'science' has been there for centuries -- long before commercially available 'fertilizers' were popular. And plants growing wild never receive applied fertilizers, however they DO benefit from the accumulation of much more organic matter surrounding their root system than is typically present in a cultivated garden.

As to the pros and cons of organic versus synthetic fertilizers, that is more a matter of personal choice. Since plants do not recognize the sources of the nutrients they have access to it really doesn't matter to them how the nutrients are supplied. In the interests of a wider environmental viewpoint, I prefer organics for the reasons outlined above. But each to their own.