Freeda - my first thought was a trellis - wouldn't a strategically placed trellis, covered with a vine, help in your case, or is the light too high up to be screened? We have grapevine growing all over one of the walls of our house and vigorously spreading into the lawn. It's actually invasive. It also bears edible fruit. It forms a dense cover from late spring to first frosts. It needs sun. Also, around here people plant juniperus virginiana Skyrocket to form tall and thin hedges (sunny spots, too). I am aware that in the U.S. some restrictions on erecting dividing "screens" - fences, trellises, hedges - probably apply, depending on the area. Also, that constructing such a "screen" - if there is enough space - might make you look unfriendly. But - if you are on non-speaking terms with your neighbour - a screen will do no further harm, and if you are on speaking terms, I imagine he would understand and forgive you building one.. Your being on his south side might be a tricky bit, if such is the case. Around where I live property owners are not shy at all to show others (neighbours, passers-by) that they are not welcome. High fences are raised, constructed in such a way as to obstruct the view. Front gates are covered with metal screens as if we lived in Hollywood. Walls are very few because the climate is too cold. But otherwise.. we all commute to the city from here (1 hour one way) and when we finally get home at night we want to relax. Judging from what their fences look like, most people need privacy for this. So they do protect their homes from unwanted attention, and it is legally allowed (or at least widely tolerated - I have not actually read the existing regulations).

btw embo ... that looks like a winter lawn in my MI .... not necessarily underfed ... at this time of year ... what i look for.. is weeds ... and that lawn is prime ... its been cared for in that regard.. which makes me thinks it has also been properly fed ... OP ... do keep in mind ... most conifers.. trees... do not need to be fed ... they are never HUNGRY ... but we insure the soil is fertile.. and take action if need me ... which IMHO ... is rare ... and in fact.. when your plants get going.. and actually put roots out under the lawn ... and if that lawn is fertd.. these things will get more than enough of anything they may need ... finally ... lawn watering.. is rarely proper watering for new transplants... do not rely on such .... though.. once fully established ... they should be rather free range ... refer to watering at the link ... ken https://sites.google.com/site/tnarboretum/Home/planting-a-tree-or-shrub

You don't have to be afraid of bamboo :-) Many people are uninformed about this plant, have no idea about the many different varieties and that it comes in two forms - running (which can take over the planet and does need a containment system) and clumping. Clumping bamboo does not grow in the same manner as running bamboo and is very well behaved.......the clump just gradually increases in its spread over time like a large ornamental grass does. No travelling vast distances underground and popping up in your neighbor's garden!! Or under your foundation! It has zero invasive tendencies. And clumping bamboos tend to be some of the most cold hardy varieties, with several species rated for zone 5 gardens. They make excellent screening plants with a narrow profile and grow to height rapidly......much faster than a tree or shrub. Unfortunately, the best and most cold hardy varieties would prefer to be sited in more shade in more interior, continental locations, only tolerating a lot of sun here on the west coast. Not sure how well it would work in the OP's garden but it might be worth considering. Cold Hardy Clumping Bamboo The giant timber bamboo Flo referred to, Bambusa oldhamii, is a very popular form of clumping bamboo but it is restricted to warmer climates. But many of the Fargesia species referred to in my link will grow and thrive in cold winter climates, provided they are sited well and given the conditions they need.

but Whistler gets quite a bit of snow each year ==>>> who is whistler??? how about just telling us where you are ... big city name.... and im thinking whistler isnt big enough for me to know where it is ... conifers are trees.. and as such.. never really stop growing at some magical height or width .... many estimates are at 10 years.. and you can presume twice that size in 20 .. all are prunable to any size you want.. but its a little more tricky than shearing in most cases ... look at this one thuja degroots spire ... https://duckduckgo.com/?t=ffcm&q=thuja+degroots+spire&ia=web get or make single leader plants.. and make sure they stay that way .. completely snow and ice proof in my MI ... it took about 5 years.. but i got rid of my whole juniper collection sue to snow load .. ice. and disease issues ... but i dont know where you are if the disease is an issue ... you probably wont find them at big box.. and you might have to pay a bit extra to fill this specific need ... but it is worth it.. imo ... also .... they are rather fast growing ... so at least they wont take a decade to get tall .... you dont mention soil type and how much sun ... both will impact speed of growth .. do you know how to plant conifers/trees .... so many question.. so little time ... ken