Hello, I am planning on creating an evergreen hedge along the perimeter of my yard. The job is going to require a large number of plants and will be an investment so I want to only have to do the job once and don't want to replace plants that die as a result of planting them wrong. The issues I am foreseeing is that the perimeter of my yard has some spots that are low lying and will remain water logged for 24-48 hours after a rain due to heavy clay soil conditions. I am in a subdivision in Lyon Township, MI that is less than two years established. Neighbors have planted Arborvitae with no luck, they have been browning, dying, and not growing much at all. I'm very cautious about using Arbs since they have not done well in my sub but am willing to admit that there could be the chance that the neighbors did not plant them right or at the right time. I'd really appreciate any help I could get about what tree (ideally cost effective) would be best suited for my yard conditions. I am open to Arbs if there is a best approach I can take and I'm also open to deciduous options as well. I've also looked at Junipers and Castle Spire Hollies. Please also advise to any soil amendment, prep work, and seasonal timing that would help ensure a healthy, fast growing hedge. Thank you very much.
Oakland County Michigan
Thank you for your question. This is an investment and you are correct to think ahead.
First, get a soil test of the area to plant. Dig several spots around the perimeter. If you find a part that seems much different from others( sand vs. clay) then test each type separately, and note down where these areas are.
Consider planting 3-4 different plants instead of a ‘monoculture’. That way if something gets wiped out, you still have a substantial planting. This article, while focused on farm windbreaks, has considerations that apply to a screen or hedge as well- https://extension.umn.edu/agroforestry/selecting-trees-and-shrubs-windbreaks#conifer-trees-1740463
Smaller, younger plants will come out of transplant shock and, after a few years, are often as tall and more robust than larger plants put in at the same time that just seem to sit a couple seasons before finally growing. Smaller plants typically cost less, too.
The wet area is a concern, and only certain plants will grow there, but they must meet the other cultural factors. Perhaps that low area could be bermed up?
Those factors to consider when selecting plants-
Soil type, soil pH, amount of sun, mature size of plants, USDA Hardiness zone( you are in zone 6), overhead and underground utilities, nearby buildings and existing trees, ability to water during the first 3-4 years, prevailing winds( usually out of the West Southwest), wildlife( especially deer can be damaging to certain plants-Arborvitae are ‘deer candy’), amount of maintenance (clipping to shape, seeds, flowers, raking leaves in fall?)
Lots to consider! Fall in Michigan is considered the second season for transplanting- spring is better to allow roots to establish over a season and so are better able to withstand a harsh winter (supplemental watering a must over that first summer/fall).
Here are some things to get you started:
The “Tree Owner’s Manual” covers how to correctly plant woody plants- trees and shrubs.
Finally, you may want to hire a certified arborist to assess your site, show him/her your soil test results, and ask for an opinion on plants choices. Considering your investment, the consultation cost may be surprisingly modest. Certified arborists have training in plant selection, care, diseases/pests; and have passed a certification test. Find certified professionals in your zip code here- www.treesaregood.org
With the soil test results and details of your cultural factors, we’d be happy to help you select plants, too.
Thank you, Laura for such a thorough response.
You are very welcome. Best Regards
You mentioned considering berming the plants/trees up. What measures should I take to berm the area up to sit the plants above the water as well allow roots to grow strong to endure winters/direct sun and grow tall and mature? Thank you.
The dynamics of a large terrace/berm, if that is what you would need to cover the area, are complex and need professional design. A large area may be better served by just having it leveled and graded. Working with a landscape designer would be best, since they have training in grading and drainage, etc.
There are many images online from landscape companies that demonstrate planting trees and shrubs on top of berms. (I can’t include them here due to copyrights). Building a terrace, a raised area of soil sometimes called a berm, would require an extensive amount of soil, and needs to be carefully designed so the runoff isn’t channeled into an undesired target, such as the neighbors yard or toward your building. A berm to accommodate arborvitaes would ideally be at least 4 feet wide, and about a foot above ground level once the depression is filled in, so the berm drains well and roots won’t drown. This would need to be mulched about 2-3 inches deep or planted with groundcovers of low junipers, pachysandra, any ground cover that wouldn’t shade or crowd the shrubs and would grow in the amount of sun they would get. Here are resources-
Mixed screens- this article has ideas, but plants are chosen for southern states- you will choose northern hardy plants. They can be planted across a wide (4-6 ft) terrace/berm, too.
A rain garden in the low spot in front of the berm could be an attractive way to handle water- https://nwdistrict.ifas.ufl.edu/hort/2014/05/27/rain-gardens-offer-option-for-problem-areas-of-yard/
Below is a picture of some gardeners at Washington State University building a small berm. Hope this helps!