It will work, but I’m sure that there are better fertilizers at a store that are better suited for trees.

I just found this on a website that highly recommends "organic fertilizing". Here:

The best way to deal with fertilizer burn is to flush the area with water to rinse away as much of the chemicals as possible. I’m guessing you used a synthetic fertilizer and not an organic one. Organics rarely burn plants. Best to topdress with an inch of compost in spring. Just move the mulch aside, add the compost and put the mulch back.

You should find this site helpful with info on Arborvitae.
http://www.aboutarborvitae.com/
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Yes, but… overfertilization leads to fast, weak growth, and then you lose the trees in a good wind… it can also set up the tree for various insect and disease problems.
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botanist

A word of caution. The first year plants struggle to get established, the second year may see a spurt of growth, and the third year they leap. You can not use a whole lot of fertilizer the first year or the second. You can use some the third. Next make sure that the surrounding area is free of grass for a couple of feet diameter so that the grass will not suck up the nutrients(saw this on a gardening show where the trees did not grow well with grass on their root structure). And last make sure your pH is good for plant growth, plants can not absorb nutrients if the pH is off. Miracle grow makes two kinds of fertilizer; regular and acid loving. Make sure you use the right one.
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why do folks think there’s some magic something that will make a plant grow faster than it would normally?…. can you make your kid grow to six ft tall before he’s out of grade school by feeding him vitamins?….NO!… same with plants.. your trees will grow their best if given what they need when they need it and pushing them won’t do a thing to make them grow faster….
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