Hello Toronto Master Gardeners’ Volunteers.
I was wondering if using cardboard as weed barrier underneath the actual woven weed barrier near the house is a bad idea. I’m assuming it will attract termites. So far, all the research online is of mix reviews. Some say termites don’t eat wet cellulose. The area we are in is shady with minimal morning and afternoon sun. We have a little patch at the front with landscape bark and I sort of remember seeing a little ‘termite’ like insects. But I’ve quickly scooped up the entire place and threw it out.
Please see picture attached at around 8am this morning. (right side) where all the tarp is.
Thanks for contacting Toronto Master Gardeners. Cardboard is a useful weed suppressant but most sources confirm that termites eat dry or wet cardboard so why risk it? A better weed suppressant that you could put over the woven weed barrier is cedar mulch. Termites do not like its taste. Keep in mind it needs to be cedar mulch because termites eat other types of wood mulch. Ideally the cedar mulch is spread two inches thick and six inches to a foot away from your wall. You could also remove the woven weed barrier and apply the mulch on its own. If termites are a problem in your area, it’s important that you know what termites look like and that you inspect the area regularly. This is especially true if you have wood soil contact in this area. Another option if you are not intending to plant anything there is to put in another set of patio stones to widen the walk way.
For more information please see the following links:
https://www.finegardening.com/article/six-tips-for-effective-weed-control
https://www.thespruce.com/termite-control-limit-mulching-near-house-foundation-2131986