There are many great fertilizers out there...I've also used Vigoro 6-4-6 from HD. I've used Dynamite either the Citrus blend, the green or Red container.
Dynamite Fertilizers

I believe its made by florikan...its slow release...
You can also do a search on 8-3-9 Fertilizers, I know they sell these mostly in South FL. Pine Island Nursery and Excalibur come to mind...Osmocote plus, Nutricote (florikan too I think?) are others.

Very important is to make sure your fertilizer has the much needed macros and micro nutrients in it, very important for the tree's health.

I've also used a product called Citrus Nutritional Spray by (Southern Ag) though there are many products out there that work well...I apply it once a month through "foliar" application during growth flushes. I apply early evening so it doesn't burn the leaves.

I prefer to fertilize my Mango trees once a month but "light" applications...I've always had better luck with more applications but in "less" amounts. I start around the beginning of March and apply the last application in early Sept. so it will go into a rest/dormancy period in late fall to early winter in hopes of getting blooms around Dec/January.

I've been doing this for the last almost 7 years and I've had pretty good results.

Lesco granular 8-10-10 is also very good for fruit trees. Sold by HD.

Do you use the same fertilizer on Avacado and Mango as citrus trees? I thought they all needed different types of fertilizers.

You can use the same Fertilizer for Citrus/Mango/Avocado...here's one from Lowe's called Sunniland that specifically says for All 3...

"Sunniland Fertilizer"

The one that Happy Fl Gardener recommended sounds like an excellent one too...will have to try that one next after I finish my 8-3-9. Thanks!

And below is the Vigoro Fertilizer that you can also use for all three also...

Here is a link that might be useful: Vigoro Citrus and Avocado

I use 8-10-10 for everything in my 2 acre yard except the lawn. When I need a bag in a hurry I buy Lesco from HD. For the lawn, I buy Sunniland's 16-4-8 acid/iron formula which can only be purchased at their factory warehouse in Sanford. It is so much better that it is worth the trip (about 40 min). When I'm there I buy their Sunniland 8-10-10 because it is less expensive at their own store. The sale's guy says that their 8-10-10 is better for fruit trees because their citrus/mango/avocado formulation is not as time released as the 8-10-10 plus there is a significant difference in minor nutrients between the two. He even proved it to me on the bag labels.

As for Vigoro, it is Sunniland's budget brand. Be careful with plant burning with that one.

Christine

I don't buy fertilizer from the box stores save Dynomite. I've used Lesco a bit but think it is low on minor elements. I'm not happy with it. I live close enough to go to Southern Agricultural supply (in Palmetto near Bradenton)...I trust them. Or a place like Harrell's in Lakeland.

Budget fertilizer is just that...ya get what you pay for and probably not that! IMHO ;-)