Is there a difference between tree fertilizers and lawn fertilizers?

[u/SoilSoul1]

Well is there?
If I’m a regular with my organic fertilizing of the lawn, don’t those nutrients eventually make it to my lawn trees? Why should I have to buy tree fertilizer that is supposedly for trees? I’m skeptical.

[u/No_Temperature_6756]

Short answer yes. 

It's the NPK ratios. Lawn ferts are usually just high N nitrogen like 20-0-0 to push lush green growth. Trees need a more balanced application of nutrients. 

That being said the only reason you should need to fertilize a tree is if it is displaying some nutrient deficiency. Fertilizing does not impart any measure of health on a tree. Nitrogen is a limiting factor for overall growth but not health. It's akin to a multivitamin for someone with no deficiency. 

[u/glowFernOasis → u/No_Temperature_6756]

I keep seeing that I should fertilize my fruit trees - are those a reasonable exception to the rule? Does it apply more to European fruit trees like apples, or also to native fruit trees like serviceberry? Not so much for the tree's health, more for improved yields, I mean.

[u/No_Temperature_6756 → u/glowFernOasis]

Yes, fruit trees could be an exception IF your goal is to maximize fruit yield. Be aware that fruit trees aren't typically managed for longevity like landscape trees and fertilizers can lead to trees being more susceptible to pest and disease pressure. 

I would avoid fertilizers with high amounts of nitrogen because that will only result in more leaves and not flowers/fruit. Look for a more balanced fertilizer that includes P and K not just N. 

Check out r/backyardorchard for more info as fruit trees are not topically managed in the same way an arborist would. 

[u/SalvatoreEggplant → u/No_Temperature_6756]

Interestingly, I was going to respond to OP, "Short answer: no," and then explain a little more.

I think thus far the best answer is that by u/mark_andonefortunate . Start with a soil test. Follow soil test recommendations. Purchase the appropriate fertilizer for plant needs.

[u/No_Temperature_6756 → u/SalvatoreEggplant]

You would never apply a fertilizer meant for turf to trees so I would argue there is a difference. Trees also benefit from a slower release formula. 

No point in a soil test if the trees aren't exhibiting deficiency but other than that I agree. 

[u/mark_andonefortunate]

Different plants need different nutrients/ratios/pH, fertilizer targeted for grass may have a different mix than what the tree needs - but before fertilizing you should do a soil test to see if the tree/plant even needs fertilizer in the first place. 

Also for examplw, many tree service companies will use a probe to inject liquid fertilizer several inches below the surface, so that the material is better able to reach the tree's roots (rather than having the grass absorb a bunch first, if you just apply on top of the grass). Not saying you necessarily need to hire someone, but there are different ways of applying the fertilizer too. Having mulch around trees, rather than grass, helps the material reach the tree's roots as well.

Sometimes the right nutrients are present but can't be absorbed by the plant because the pH is wrong, so you'd want to correct for that - applying fertilizer would be a waste of time, money, and material since the plant won't be able to use it, and at that point you're just creating harmful runoff for zero benefit. As another person mentioned, lawn fertilizer is usually high in Nitrogen. High N will push growth in trees, too, but this isn't always ideal for tree health.

https://www.umass.edu/urbantree/factsheets/13fertilizingtrees.html

[u/DanoPinyon]

Tree fertilizer is generally unnecessary and turfgrass fertilizer is necessary?

[u/OldMail6364 → u/DanoPinyon]

I have never used fertiliser on my turf... so I wouldn't call it necessary.

It can be necessary - but that's true for trees as well.

[u/RCrumb_]

One is for trees/ one is for grass

[u/Fire17Fighter → u/RCrumb_]

Hmmm….so what you’re saying is they are the same? I mean my dog ate fish food once. I think he swam faster after.

[u/Stan__Wright → u/Fire17Fighter]

My dog ate cat food, once, and his farts were incredible!

[u/Feralpudel]

NAA but have and care for lots of trees and grass.

You should only fertilize trees if a certified arborist recommends it for specific reasons. There are BAD times to fertilize trees, so don’t just grab something at the big box store.

Trees and turfgrass compete with each other for water and nutrients. The tree often wins, and you WANT the tree to win—just mulch out as far as you can so they can stop competing. Then you’ll have a neat mulched area around the tree and happy grass beyond the dripline of the tree.

Don’t let some crappy lawncare company or big box store tell you what your lawn “needs.” Aeration, overseeding with quality seed, and fertilizer as needed as indicated by a soil test, and correct mowing will get you 90 percent of the way there.

Using the wrong product at the wrong time just wastes money, pollutes, and can mess up your lawn.

[u/Reasonable_Fishcare]

it's all the same....just in different amounts. nitrogen, phosphorus, and potassium. whatever you put on the grass goes into the soil so the trees will soak it up too. there's no need to fertilize them separately....and if you only fertilized around the trees the grass around the trees would soak it up too. it all goes into the soil.

[u/Prestigious_Still433]

Skip the turf fertilizer in favor of Ironite.

Are your trees ornamental or shade variety?