Too cold a climate? Lawn chemicals? You should plant in a grass-free area like a bed or individual planting circles, rather than have the lawn come right up to the new trees.

Which are not pines but instead emerald arborvitae (Thuja occidentalis 'Smaragd').

Timing certainly would suggest cold damage or something else that happens during the winter.

If you are buying these balled in burlap there may be a problem with moisture levels inside the field soil balls that develops over time, maybe they are getting too wet during the winter.

Any wrapping materials that may be on them (burlap, twine, nails) need to come off at planting.

Three years in a row sounds like user error or overspray of chemicals reducing vigor so winter can finish them off. Planting improperly in grass and no supplemental water might do it.

Dan

To clarify this we bought the plants in the spring time and planted around Memorial day. The plants did well all spring, summer and fall. We put the burlap bags over them to protect them from Minnesota winters. When we removed the burlap in Mid to late April the plants looked fine. We water them a couple of times a week which could be a problem but not sure. About 10 feet from the closest plant is a vegetable garden and I do not use any types of chemicals. I use a mild starter fertilizer on the lawn twice a year and in my vegetable garden I only use fish emulsion and compost and dehydrated chicken manure but only in the garden. My last lawn fertilizer was last fall and have not put any down this year. I am not sure why being planted around grass would be a problem.

If the thujas you're planting are hardy enough for your Z4 climate, I'd suggest the burlap bags may be the problem if you've been putting them over the top of the plants in direct contact with the trees. If wet burlap comes in direct contact with the foliage, it can do considerable damage when it freezes. A burlap bag, because it does not allow for much air circulation with a closed top, could also possibly cause overheating. Burlap makes a good winter sun and wind break, but it should be kept off the actual foliage.

winter protection is a wrap with the top open..

if you literally 'bagged' them... then they lacked air circulation.. and heat release.. on those relatively warm winter days ...PERHAPS causing some type of thaw during the day ... and re-freezing at night ... if this happens.. tissue can not take the freeze/thaw/freeze cycle repeatedly during winter ... being evergreen .... the final straw is the onset of summer temps that finally desiccate the green to brown ...

conifers need no fertilization ..ergo lawn fert is counter indicated.. as well as drift issues of high nitrogen on the foliage ...

ken

Yes, I agree after the clarification that the coverings were not properly done. Many, many instructions out there on how to winter wrap. And how to keep turf away from woody plants.

Dan

The first year we did not use the burlap the plants looked brown in the early spring. The second two years the plants looked great but eventually turned brown like in the picture. My thinking after reading these posts may be a watering issue. Planting close to grass the grass is stealing the water. If I use compost around the plants after planting and water real well would this make a difference. Is possible the root system is not getting deep enough or that the water is not getting to the roots? I notice a lot of these types of shrubs wrapped in burlap for the winter. Maybe there is an internal wrapping people are doing to keep the burlap off the foliage. We water with house water (which is not the best) at least two or three times a week depending on how much rain we get. Is it better not to get the needles wet and water only at the base being careful not to splash onto the foliage? This is what I have to do with my tomatoes or I fight fungus problems and have to dust the plants. Thanks for all the suggestions.

Trees will need fertilizer if and when a soil is deficient, same as any other type of plant.

Do not amend planting hole back-fill.

If others nearby are being wrapped as well, then probably your location is really just too cold for this particular item.