grass under trees

Asked November 13, 2016, 7:19 AM EST

Hi... we moved to Mounds View a year ago.... I was a golf course supt. since 1981 so I know a little bit about trying to grow grass in different soils and in shaded areas, but I tried to grow grass under the line of trees? in my front yard, by cleaning the area real good, putting down a load of expensive grass seed for shady areas, and then top dressing with mulch from the Ramsey County recycling center. I do have an irrigation system so it was watered daily/regularly. I did the same in the back yard and that grass came beautifully, but the grass in the front yard "kind of" germinated and then quit.... leaving me right back where I started. Can you look at the pictures, tell me what kind of trees I have in this line, and then make some suggestions as to how to get grass to grow under them. I don't like gimmicky landscape rock etc, and prefer a healthy growth of grass.... suggestions, welcome, and appreciated. Thanks.Dennis

Ramsey County Minnesota

6 Responses

Sorry for the delay. ID took a while as I do not think of arborvitae as a tree but rather a shrub. But that is what you have. It is also known as Northern White Cedar: I see several possible problems here. I am concerned about the multi-trunk situation. Arborvitae in shrub form has several trunks which tend to sometimes pull apart but they can be tied together loosely to prevent this. However, you now have trunks with weak junctions. In a storm they could break and tear. Look especially at the third tree in your center photo for an example. Also, the shade from these trees stops sunlight from getting to the soil. Grass is a full sun plant, even shady tolerant grass needs some sun. Finally, they are so close to the street that it is highly possible there is a problem with snow/salt being plowed up. You could do a soil test to see if the soil is contaminated. Here is a link for info on that: You may end up putting organic mulch under the trees and forgetting the grass.

Hi Barbara..... first, as usual, thanks for the information and reply..... I wish there was a better answer, but I guess not.... They are near the street but, the grass on the blvd. is healthy and green for about ten feet from the road towards the "trees" ..... sorry, but to me they're trees.... I understand the need for sun, but the west side of these do get a ton of afternoon sun and still don't do well... I also used a high priced shady grass seed.... I think I will give it one more shot next summer.... and try some black dirt from ??? and I also do need to do a soil analysis (I do my own....) for this area and one other, that for some reason, will not grow grass as well... I was hoping you were going to say, "this is an easy problem to fix" and I guess that probably isn't going to happen... I will try again next summer... thanks again... Dennis

Also consider that is a dry shade area. The roots of the arborvitaes take up the moisture. Good luck.

The lawn does have an irrigation system that hits this entire area on a regular basis.... especially when I seeded it... I was hoping to hear that the "trees" dropping some growth on the ground, meant the ground was too acidic or something that was an easy fix.... I will start from the beginning next spring by doing a soil sample test from this area, and determine the fertilizer or whatever I need to do in that respect, and then when the ground temperature is appropriate, try to over seed the entire length of this row again.... and hope of the best. I know the alternative is a mulch layer/ river rock solution type of thing, but I just have never liked that "look" and prefer grass... Thanks for the information though and apparently, there is no easy/sure fire/simplistic answer to this one..... all I can do is try.....

Hi..... Just one final update... I did take soil samples from my lawn, both the front and back yards and especially, under the arborvitae just to make sure there were not any other issues.... there weren't. We just moved to this location a year ago, and I talked to my neighbor who said that the family that lived here for three years, did nothing to the lawn. I tested the samples and confirmed that. I did fertilize the lawn twice last summer but from the test results, that is not even close to what the lawn needed and the reason the grass was so weak in the entire front yard. If anybody has any ideas/locations of where to buy GOOD lawn fertilizer, I would appreciate it.... I am tired of box store fertilizers. Also, I do have time to fertilize yet this late fall, because this one inch snow will not hang around. Any ideas of what I should apply? Thanks... Dennis

You probably should have your soil test done by the UMN Soil Testing Laboratory instead of a do-it-yourself kit. They will advise you as to the NPK you should have for your particular lawn. With that information, you can then find a fertilizer that will meet those specifications. Here is a link to that: There are good fertilizers available but you need the right combination. Also, I don't know what type of soil you have but if it is clay, you may want to consider aerating it next year. Please take the time to go through our various publications we have for you regarding lawn care: