Often grown for ornamental purposes, tall grass species like pampas grass can reach heights of 8 feet or taller. Their sheer size can sometimes present problems, such as if they start encroaching on other plants or if you need to remove them to make way for new planting beds or a garden structure. Whether you're facing a weed grass invasion or want to remove an ornamental grass, you have several strategies at your disposal, with varied ranges of toxicity and physical labor.
Pull on protective gear, such as gloves, pants and a long-sleeved shirt. Some tall grass species have leaves that create safety hazards because they bear sharp edges or barbs.
Shear down the tall grass to a height of 1 to 2 feet using pruning shears or a hedge trimmer. Rake up the fallen blades and dispose of them in your trash or in your mulch or compost pile.
Dig out the root clump using a long-bladed shovel. Insert the shovel at a downward angle all around the root clump to loosen it, and then grab the clump with your hands and pull upward to uproot it.
Turn the tall grass's root clump upside down to keep it from rerooting, a common problem in several tall grass species. Once the root clump has dried out, dispose of it.
Put on protective gear, such as gloves, a long-sleeved shirt and safety goggles. Not only do several tall grass species create a safety hazard due to sharp leaves and barbs, but glyphosate-based herbicides are toxic if they come in contact with your skin.
Cut down the tall grass at its base using pruning shears or a hedge trimmer.
Wait for new growth to appear. Ideally, wait until 2 to 4 inches of new shoots start growing from the grass's root clump.
Apply a glyphosate-based herbicide to the new grass shoots according to the manufacturer-specific labeled guidelines, misting them evenly but not applying so much herbicide as to create drippage. This nonselective herbicide kills all vegetation, and the new grass shoots will carry the poison down to the roots and kill the entire plant. If you were to spray glyphosate on a mature tall grass species, the woody stems may absorb less of the poison, while the tall height would make it difficult to apply herbicide safely and effectively.
Put on protective gear, such as long pants and gloves.
Cut down the grass clump as close to the soil level as possible.
Moisten the soil surface with water.
Lay a clear plastic tarp over the grass clump, and weigh down its edges with bricks.
Wait six weeks. The sun will heat the grass through the plastic tarp and bake the root clump to a heat of approximately 140 degrees Fahrenheit, effectively killing the grass and any other weeds and weed seeds in the dirt.
Things You Will Need
- Protective clothing
- Pruning shears or a hedge trimmer
- Long-blade spade
- Glyphosate-based herbicide
- Garden hose
- Plastic tarp
- If you choose to kill your tall grass with herbicide, wait until the weather service doesn't forecast rain for a week. Rainy conditions can rinse the herbicide from the plant before the new shoots fully absorb its toxic effects.
- University of Florida IFAS Extension: Cortaderia Selloana Pampas Grass
- University of California Weed Research & Information Center: Pampasgrass and Jubatagrass Threaten California Coastal Habitats
- Texas A&M AgriLife Extension: Grass Control
- University of California Statewide Integrated Pest Management Program: Soil Solarization for Gardens & Landscapes
- Hemera Technologies/Photos.com/Getty Images