Shop Products
Houzz Logo Print
mpg2004

planting in front of arborvitae hedge?

mpg2004
11 years ago

Hi,

I have a ~20-30' tall 15 year old arborvitae hedge. I am trying to plant a second row of shrubs in front of the hedge (about 3 feet in front of the arbs) but everywhere I dig I run into roots. I don't want to chance killing the arbs, since they provide needed privacy to our property! Is it ok to snip one or two of these surface roots (they are about 2" or so underground) or will this kill off a portion of the arborvitae? I'm currently trying to plant some ornamnetal grasses, so I don't need to dig very deep, but I do need to dog down some. How deep do most of the arbs roots typically run? We are in a VERY windy area, if that makes a difference.

thanks!

Michelle

Comments (10)

  • mpg2004
    Original Author
    11 years ago

    Thanks for the reply! I was typing quickly -- I am planting a mix of small shrubs, perennials, and ornamental grasses. Mostly everything is in quart and 1-2 gallon containers, and I've decided to place the larger shrubs into holes left from the rosebushes we pulled out. I am finding many tiny roots (like a hair width) right at the surface and some larger (about the width of a finger) about 1-2" down. It's the finger width ones I am concerned about cutting. We did pull a couple of 4' tall mugho pines from the area, so it's possible they are leftovers from that, but they seem very "wet" and alive so I thought they went to the arbs. I wish roots came color coded so I could tell what was what!

    So... I should be ok cutting the occasional root, right? I'm not planting anything behind the arbs, so at least half the root system isn't being disturbed, but they are growing up against a fence, so I don't know how extensive the roots are back there.

    thanks,
    Michelle

  • strobiculate
    11 years ago

    Finger width? i may be cautious about ankle sized roots...but honestly arbs are noted for having a fibrous root system...not saying the primary/secondary/tertiary roots don't exist...and on something the size you indicated they almost certainly do...but that its not some thing to worry about unless you start.trenching

    so this mixed shrub border you are putting in near the arbs...how big do these things get?

  • ken_adrian Adrian MI cold Z5
    11 years ago

    the problem planting near very large arbs.. with the fibrous roots is going to be water management ... they will suck the life out of everything.. as time goes by.. perhaps why there was prior failures .... not that it cant be done.. just that you are going ot have to become an expert at watering under them ... i call it PROPER WATERING .... which has been addressed a bazillion times.. link to brandons bible ... where watering should be addressed ..

    i would work around anything bigger than an inch ... just move your hole over a bit ...

    but i would not be concerned at all with a relative few root tips ... as i noted.. the root mass is easily twice the tree.. so a little disturbance of .00099% of the whole shouldnt make a bit of difference..

    besides the fact.. that you will be heavily watering the new additions ....

    my bigger concern.. is that these are extremely old plants.. i would like to see a picture.. you ought to be thinking about the long haul.. should they fail .. if you will be at this house for decades ...

    ken

    Here is a link that might be useful: link

  • mpg2004
    Original Author
    11 years ago

    Thanks for the advice! We have been working with a landscape designer to come up with our plan -- we are trying to get a 2nd layer of different color/texture that will add more privacy, especially if one of the arbs dies and needs to be replaced. Arborvitae seem to grow extremely well in this area. What was originally planted as this 2nd row (15ish years ago) was a mixture of tea roses and mugho pines. We decided to remove most of the roses because they were too shaded to grow very well (and so were quite scraggly) AND the kids kept getting pricked by the thorns. The mugho pines simply blended in with the arbs, so they didn't add any interest.

    We do have a 12 zone irrigation system, so I should be able to figure out how to water everything well. I think the rose bushes suffered from lack of sunlight more than water. The mugho pines were growing quite well, I just wanted something that was more interesting against the arborvitae.

    The plan is a mixed very informal sort of hedge row -- lots of silver king euonymous (an evergreen to lighten up the area), interspersed with some rose of sharon, black lace elderberry, ornamental grasses, and possibly a butterfly bush or lilac. We're trying to get more year-round interest with easy-to-grow plants.

    Here are some pictures of the hedges I'm trying to plant in front of.

    {{gwi:11715}}

    {{gwi:11716}}

    {{gwi:11712}}

  • ken_adrian Adrian MI cold Z5
    11 years ago

    hey

    i would get rid of the overgrown balls on the driveway.. its amazing how those cute little balls ... turn into concrete eating nightmares over the decades ... cant even open a car door near them ...

    what is the vine.. if its grape .. get rid of that ...

    as to the arbs.. i would double or triple the bed in front of the arbs.. and plant so that you leave 2 to 3 feet of walking space between the mature size of what you planted.. and the arb ...

    its a bit of a fools errand.. to jam stuff right up against the side of the arbs.. as they will continue to widen.. and the plants you plant will also widen .... so in 5 years .. they will be suffocating each other ... your LA should know that ...

    thanks for the pix

    ken

  • strobiculate
    11 years ago

    Q: you think roses suffered from lack of sun...yet the replacement is ornamental grass?

    the roses probably suffered from a bunch of things, which the lack of sun did not help with...yet grasses almost without exception are sun loving plants, more so than roses.

    i was curious about spacing because a.backdrop of arbs makes anything you would plant stand out and become much more visible. but plant them too close to arbs and you run the very real risk of shading out the arbs. grasses are not small plants at maturity.

  • lolauren
    11 years ago

    I'm also in E. WA so am curious if you are in a dry part? If so, perhaps the soil was too alkaline for the roses to thrive...

    It looks like your planting bed is right next to the arbs. Is it possible to plant further away, where you currently have grass? I can't answer your question on roots of arborvitaes, but I wouldn't want to jeopardize your wind screen (our wind is terrible!)

  • mpg2004
    Original Author
    11 years ago

    Thanks everyone! We're in Richland, which is a very dry part of eastern WA. When we bought this house, there were many many many roses; we decided to keep the ones that are doing well and replace the ones that weren't with other shrubs. The roses obviously add a lot of color when they're in bloom, but they just blend into the arborvitae hedge the rest of the year. Besides trying to add more seasonal interest by replacing the roses, I'm also trying to attain a more kid-friendly and lower maintenance yard than *all* the roses created. The wind screen & privacy provided by the arbs IS very important to us, so I will work on moving the planting bed for the mixed 2nd hedge out further into the grass. I had been hoping to reuse the old rose holes, since I could easily replant in those without severing any more roots. And moving the bedlines into the lawn involves relocating sprinkler heads; I had planned on moving 1 to create a larger planting area where we didn't have any rose border at all, but was hoping to avoid moving them all. The picture shows the bed a bit narrower than it truly is -- the rose holes are between 5' and 3' from the arbs. I probably took on more than I should have with trying to get this all planted so quickly, but I really wanted to get new plants into the ground before the heat of summer arrives, and get them planted as soon as I can so they have a chance to start growing and providing some more privacy.

    What sparked my initial post was trying to plant a small blue oat grass. It's a tiny plant, so I wasn't worried about shading the arbs and I thought it would be ok to go about 3' away, but that was when I was running into the roots that I wasn't sure I should touch. I tried moving to different spots and kept running into those same roots.

    Yes, the "meatballs" along the driveway are also on our eventual list of things to go.... It's a bigger job than we can do ourselves, so it has to wait for right now. I'm also not sure I'm crazy about the landscape designer's suggestion of a mix of wintergem boxwood & spirea to replace them, but I'm not sure of what else I would do there.

    The vine growing up the white posts is wisteria -- messy as it is, it provides a nice amount of shade for our patio and was so lovely when it was in bloom that it stays! :)

    thanks again,
    Michelle

  • lolauren
    11 years ago

    Michelle,

    I'm in Tri-Cities too. :) It's nice to see someone else local on GW.

    I'm curious who your landscape designer is... (you can message/email me if you're willing to share and don't want to put the info here.) We just had some landscaping done by one of the larger local companies, and I also frequent all of our nurseries..... It is amazing what recommendations the owners give on plants. I am sure a lot of them are just trying to push product. Anyway, the owner of the nursery between Clearwater and 10th on Columbia Center has given me very honest, intelligent advice in the past... it might be worth your time to talk to him.

    How much sun does that spot get?