Not sure where you’re located, but here in upstate NY, Norways grow like weeds and thrive on neglect.

In fact, my next door neighbor, who’s not very “gardening-inclined”, had a whole new perimeter of Norway Spruce planted around his property two years ago, and even though I don’t think he ever watered them once after planting, they’re all doing just fine with zero care.

Have you identified a specific issue(s) with your trees that needs to be addressed with fertilizer and “spray”?

I'm in northern NJ. I did have issues with a mite or similar that caused new growth to curl up and grow in the wrong direction on one of the trees. It was a few years ago and have forgotten the exact name. I also have a bit of needle casting on one of the blues. Anyway, I spent a lot on these trees and I decided to invest in a reputable company to make sure they are in good shape. I have another landscape guy who recommended fertilizing and recommended the company I use. I had an old weeping hemlock with a bad wooly adelgid problem that I wanted taken care of as well. I'm normally a DIYer but for the reasonable cost I thought it best to leave it to the experts.

Due to slow business during covid I decided to skip a year and take care of things myself. I considered doing nothing but fertilizer is cheap and I want to encourage the trees to provide a barrier as quickly as possible. I understand your point about not needing anything. However, some are growing faster than others and I'd like to fertilize just in case. If I am going to take the time to do it I want it to be effective, of course!

imo .... established trees NEVER need fertilizer ...

and if you fert your lawn .. they will get more than enough ... of what they dont need ...

no one fertilizes a forest ...

you give no facts that indicate a soil amendment is needed ...

a perhaps once in a lifetime bug attack does not mean you need to spend the rest of the trees life treating for said bug .. it may never come back.. and if it does.. then you deal with it then ... otherwise treating for something that isnt there would basically be pollution ...

needlecast on pungens is endemic ... you might be better off spending the money on removal.. rather than a lifetime of treatment ... but i bet that isnt going to happen.. lol ...

protect yourself properly when trying to spray a 15 foot tree .... it might not be as easy as it sounds ... without professional level sprayers and hazmat suits .... and they will never get smaller ...

ken

I entirely agree with posters above. I have both kinds of trees planted on my prop and never gave them any special care other than occasional watering during prolonged spells of hot and dry weather when they were young.

I never noticed any problems with my NS. BS at the beginning developed similar problem to yours (new growth to curl up and grow in the wrong direction) on some branches, but were able to overcome the disease without any intervention on my part.

Thanks for the replies, ken and windberry. One of the reasons I hired the tree company was to take care of the bug problem on one of the NS's. It was big enough then that I didn't care to have horticultural oil raining down on me.

Maybe I'll skip the fertilizer altogether this year except what the lawn provides.