arborvitae allelopathic?

cassiope(03/WI)December 5, 2004


I posted my problem with native plants, and many people offered great suggestions - which I fully appreciate - BUT - I've spent 8 years tackling this problem and want to do it absolutely right this time.

A section of my garden is framed by 2 tall arborvitae on the north side and a Black Hills spruce on the west side. For 8 years I've been unable to grow anything here successfully. The soil is sandy (I do keep amending it with compost). Do either of these species inhibit other plants somehow? Whenever I prepare the soil for something new, I dig up lots of shallow roots. Since it's at the back of the border I need something tall. Thank you!

Thank you for reporting this comment. Undo
Rosa(4ish CO Rockie)

This site lists Thuja plicata as having leaf litter that is slightly allelopathic but no other species are mentioned.

However, this one states that there is no documented evidence of this occurring:

I canÂt find anything more specific but would suspect that a combination of shade, and water competition from those abundant, strong, fine roots near the surface is more likely the problem.

Sorry, but I donÂt have any plant suggestions for you.

    Bookmark   December 18, 2004 at 12:48PM
Thank you for reporting this comment. Undo

Thanks Rosa-
I think you're right. I find it very frustrating though, this was to be my beautiful border garden with the conifers acting as a landscape foil. As it is, it's my least attractive bed. I think I need to find a plant that also has competitive roots, or else one that can suffer through dry conditions.

    Bookmark   December 20, 2004 at 12:19PM
Thank you for reporting this comment. Undo
Rosa(4ish CO Rockie)

Dry shade is sure a tough one. Maybe others in your area have some experience and some good recommendations....
You might try posting for plant ideas on the native plants, perennials and shade gardens forum.
Good luck!!

    Bookmark   December 20, 2004 at 4:34PM
Thank you for reporting this comment. Undo

I do believe that arborvitae litter is not conducive to other plants in some way. I have found that salvia greggi seems to grow happily with it for some reason.

    Bookmark   January 9, 2005 at 8:21AM
Thank you for reporting this comment. Undo

Salvia g. sounds perfect except for it's hardiness. Do you know of a plant with similar tolerances but also cold hardy (I'm in zone3/4)?

Maybe if I do annual salvias?

    Bookmark   January 14, 2005 at 3:41PM
Thank you for reporting this comment. Undo

Maybe an agastache? I love Agastache rupestris, easy from seed, and it comes from the Rocky Mountains, so should take cold.

    Bookmark   January 16, 2005 at 4:50PM
Thank you for reporting this comment. Undo

Great idea!
I don't know if anyone else gets frustrated with the seasons - I wish I could try many plants in one season for this spot, so I'd be sure to have success.

I just checked in my High Country Gardens catalogue. They have A. rupestris - it is very pretty. I love their stuff, but have been hesitant to buy many of their plants because of the difference in rainfall and humidity between Wisconsin and New Mexico.

I do love Agastache. I think I will give it a go. Another problem I have is my garden gets too crowded. I think I need to dig up more lawn this year! (so far I have New Jersey Tea, Baptista australis, and now A. ruprestris slated for that spot)

    Bookmark   January 16, 2005 at 5:44PM
Thank you for reporting this comment. Undo

USDA actaully lists arborvitae as not-allelopathic, but their database is not perfect. Too bad I'm out of the A.rupestris seeds for this year. I have some other Agastaches, but doubt they're hardy for you. Keep me in mind for trading next season!

    Bookmark   January 17, 2005 at 5:06PM
Thank you for reporting this comment. Undo

Thanks Brenda for the info. My soil is the opposite of yours - very sandy which in combination with competition with arborvitae roots might be the problem.

It'd be fun to trade seeds with you. I generally don't collect seeds from my plants - I usually buy all my seeds. But if you're interested, I have alpine plants, native (mostly shade) plants, and a few sun loving natives. (I'm guessing only seeds exchanges are possible) Unfortunately our yard is small - so I'm limited. So next season - I'll look you up!

    Bookmark   January 17, 2005 at 9:12PM
Sign Up to comment
More Discussions
Identify plant
What is the name of this plant?
Large leaves.
This NOID doesn't have any flowers, but sure has some...
Difficult spot and soil for lawn
We've lived her since fall of 2012. For two years we...
Foundation planting help
I posted a whole long message but I think it was lost....
Report: Black Walnut Rose Plantings
Some months ago there was interest in what roses might...
People viewed this after searching for:
© 2015 Houzz Inc. Houzz® The new way to design your home™