do NOT even contemplate in between them ... too much water competition ... first pic.. come at least 8 to 10 feet toward the camera ... and you will succeed much easier.. and faster ... do not get sucked into planting everything along the lot line.. [i am presuming you are trying to hide the neighbors house behind] ... the fact that the myrtle .... is alive.. but not aggressive.. alerts me to such ... it wont grow between and way under the tree.. only thriving near the edge.. where there is more light and less root competition ... are there power lines running thru those trees??? ken

I would not do anything to alter the soil near the tree. I would not put any extra soil over the roots (except maybe a little soil high in organic content to keep any lawn mower from clipping the exposed roots when the grass is mowed--no more), and I would not try to level anything out either. Planting grass under a Norway spruce tree may or may not work--grass does not grow well under Norway spruce trees unless there is a lot of light from the sides. But there is no harm in spreading a little grass seed and seeing if it takes. The best thing may be to mulch around the tree. As for the tar--not a good idea. When Norway spruce limbs are pruned off there is no need for any treatment unless the limbs are very large. I doubt a 35 foot tree would have any limbs large enough to need treatment with anything when pruned. If you left any stub when you cut the branches, you could cut the stub off and that will remove the tar. Or you could just scrape off what you can and leave it at that. In any case, the tar will not kill the tree. The only danger is that the tar will trap some moisture (that is already in the tree and the wood) and make it more susceptible to fungal rot. But the susceptibility should be low in any case. I would not worry much about it. --Spruce

Robusta should do good in your climate.

Google "Picea Abies" You'll find all the info there. Rai