Comments on: How Do I Kill Grass Under My Landscaping?

By: Garden Design

Garden Design — Sat, 21 Nov 2009 19:40:32 +0000

A combination industrial type vac and power blower in a convenient lightweight unit. Garden Design

By: resolute

resolute — Sun, 25 Oct 2009 12:03:36 +0000

You will need to identify the type of grass that has become a weed. Take a sample to the garden center and have a pro identify it.
Blue grasses are easier to kill than…zoyzia (sp) or Bermuda as their root systems are very, very aggressive.
There are OTC chemical agents out there you can by to spray on the species you wish to kill.
USE caution by reading all directions thoroughly, wearing Personal Protection Equipment and not accidentally nailing the plants you wish to keep…
If it is a small area, a spray bottle will work. For applications of large areas I would entertain using a good quality pressure sprayer…

By: nowaynoh

nowaynoh — Sun, 25 Oct 2009 08:51:19 +0000

If the stuff you put in is mostly trees and shrubs, then I’d cover most of the open space (not too close to you new plants) with black plastic. The sun will heat that up, and over a week or two will bake the grass underneath. For what is close to your new stuff, pull. Pull the tops off every day for three weeks, and most of it will be gone.

By: chantell

chantell — Sun, 25 Oct 2009 06:53:43 +0000

Landscape fabric will do the trick (the black membrane as someone else mentioned). However this doesn’t mean you’ll never have weeds or grass going in that area again as future seeds seeds carried by the wind will just land on top of the fabric and germinate. At least however it’ll be easier to manage and weed.

By: Krian

Krian — Sun, 25 Oct 2009 02:02:07 +0000

I’m assuming you mean a turf grass as opposed to an ornamental grass, but here are your options:
First, covering the grass in soil will kill it, however the soil needs to be at least an inch thick, and then consolidated, and ideally a heavy soil rather than a sandy soil. If you trample down the soil the grass has difficulty penetrating through the compaction, and being unable to photosynthesise(sp?) it will die off.
However, if the soil layer isn’t thick enough or its quite loose, the grass blades will penetrate through the soil. Additionally it may not be the original grass, but grass seeds that have germinated within the soil, particularly weed grasses such as poa annua – annual meadow grass.
However there are alternative controls, first off chemical controls:
Any systemic herbicide will kill of the turf, but a herbicide designed for clearing pathways and patios will generally be your best bet. However you will need to keep it away from your desired plants to ensure there are no ill effects. Different herbicides have different requirements so check the label or ask at the garden center.
Organic control:
Use of a landscape fabric will control the grass, you can purchase this at most garden centers, simply lay it on the area you wish to control and leave it for at least a month. This will cause the lawn to die off. If you don’t want to pay for a specialist material you can use old carpet as a form of control, or as suggested earlier black bin bags will do the trick as long as they are thick enough, just make sure that you regularly water your new shrubs if using bin bags as they are impermeable to water and can cause drought problems to your plants.
You can also dig in the grass – although turf benefits from root pruining it doesnt like regular disturbance, simply turn over the soil on a regular basis and the grass will eventually die off, you should be aware however that digging up grass will disturb the seed bank within the soil and cause a variety of weeds to spring up.
Using a hoe is also effective, make sure its sharp (A dutch or D Hoe is usually best) and simply scalp the turf, although the grass will regenerate from the base, particularly tufted grasses like festuca rubra ssp commutata if the grass is cut to a height below 1cm it will fairly rapidly die off.
Finally if you decide to add any more borders or island beds to your garden your best bet is to remove the grass first, use a spade or preferably a half moon edger to cut out strips of soil, then use a hoe to slice through the ground at a depth of about 5cms, then you can simply lift the turf. Once lifted stack it somewhere with the turf side down and cover in black plastic. After a few months you’ll have a good quality loam to top dress your borders with.
Hope that helps.