Stressed plants should not be fertilized (unless nutrient deficiency is the only cause of decline or leaf discoloration, which is not the case here). Mature trees also do not generally need fertilizer, and a laboratory soil test should be performed first to determine if the soil is actually lacking any key nutrients. (We can help to interpret those results if desired.) If the soil is not deficient, adding more nutrients won't solve a problem, and might even stress roots more. If roots are not able to absorb what they need from soil containing sufficient nutrients, then either the roots themselves are unhealthy (something fertilizer won't fix) or the soil acidity (pH) is outside of the range of that tree's preferences. In the case of the latter situation, nutrient deficiency symptoms manifest in the foliage, and a soil test will reveal the pH issue, neither of which is likely in this situation.

Drought can impact plant nutrient absorption because roots uptake nutrients dissolved in water. Even so, the more critical issue is roots getting enough water in the first place, and if drought-sensitive plants weren't being watered occasionally this past summer, root damage or dieback (which can result in canopy dieback as well) might have occurred, for which there is no cure. New root growth can replace some of what was lost over time if the tree recovers, but any dead canopy branches will need to be pruned off once they're easier to detect (such as next spring, when new growth is emerging, not in autumn when leaves are shedding).

Leaf loss in the canopy mid-season is not an encouraging sign. While premature fall color and shedding near the end of summer can be typical of moderate stress, that early of a denuding suggests that some branches are weak or dying, perhaps from issues not related to this most recent drought. The tree pictured is hard to identify to species, though it looks like either a purple-leaved variety of Norway Maple (our main guess) or a Sugar Maple whose leaves turned brown as they died. Norway Maple is non-native and invasive, so if you do need to replace the tree, we do not recommend planting another one. It also prefers cooler climates than Maryland experiences. Sugar Maple is native, but barely occurs naturally in Maryland for similar reasons -- it's more widespread in the wild in areas to our north, or up in the mountains where summers are cooler. Red Maple is a local and abundant native maple species that you could replant with if you prefer to keep a maple in this location. (Otherwise, you have plenty of options for other tree species.)

Tree decline can't be reversed, though there are many causes behind it, some of which can be overlapping or which may have begun years before symptoms became obvious. We suggest that you have a certified arborist (perhaps another one that isn't affiliated with a tree company, for a second opinion) evaluate the tree to look for causes of branch dieback, such as borers, fungal cankers, or included bark at the junction of two main limbs. Arborists cannot cure these conditions, but can determine where to prune out unhealthy wood to slow or prevent the spread of a problem to other areas of the canopy. Even if a fertilization were warranted (we don't think it is in this case), it's a short-term solution that doesn't address whatever issues lead to this point, be they drought, a too-soggy root zone (in a prior year, maybe), heat stress, or secondary issues like borers and wood decay.

From what we can tell from manufacturer/distributer information, Forti-Phite is only a fertilizer (made in several formulations), not a pesticide or fertilizer-pesticide combo. Information about its nutrient analysis can be found online in fliers like the one in the linked page (this is not the only one). If used according to label directions, there shouldn't be any safety concerns that we are aware of. It might not be considered organic, though, if that is your preference.

For a tree that's been struggling or declining for several years in a row now, fertilization isn't the answer and won't save the tree. If an arborist doesn't have any other suggestions, then either the tree can be left to decline to the point of too much eyesore to keep (or a fall risk is too great) or it is replaced proactively so a new tree can be installed. Early and mid-autumn is a great time to plant trees, though you can do so just about any time of year you're ready to plant as long as the plant's watering needs can be monitored. If you're interested in using a native species, several nurseries participate in the DNR's Marylanders Plant Trees program, which provides rebate discounts that will reduce their cost.

Miri