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Weed Killer for Zoysia Grass

wispy weeds image by Andrew Kazmierski from

Taking care of your lawn is the first step in preventing weed infestation with your zoysia grass. Lawns that have become a breeding ground for weeds often find difficulty in effectively removing them. It is important to identify the weeds before deciding on which herbicide is the most effective to be used.

Zoysia grass

Zoysia grass is a very invasive grass that spreads without being seeded. It is effective at crowding out unwanted species in the lawn, but is difficult to contain. It is a slow-growing grass that does not need to be maintained as often as other varieties. Unfortunately, it takes a longer time for zoysia grasses to recover from repeated damage due to weather, animals and pests.

Herbicide applications

There are two types of herbicides that can help protect zoysia grasses from weeds, pre-emergent and post-emergent products. Pre-emergent herbicides actively stop and prevent the germination of weed seeds present within your lawn without damaging the grasses. Post-emergent herbicides are used for weeds that have already come up from the soil. These types of weeds are harder to use because of the potential damage to lawn grasses.


Post-emergent herbicides work in two ways, either through contact or systemically. Contact herbicides affect the plant wherever it touches, damaging the outer surfaces of the plant. Systemic herbicides work in reverse, damaging the inner parts of the plants. Systemic herbicides are more effective on older, harder to remove weeds and contain either glyphosate or triclopyr.


Selective herbicides are used to remove specific weeds within the lawn without injuring the grass. Non-selective herbicides will kill everything they touch and are usually used before lawn planting. Herbicides that are pre-emergent and post-emergent are available as selective and nonselective varieties.


Three chemicals that are common in herbicide products are sethoxydim, fluazifop, and clethodim. Sethoxydim is used for lawns, vegetable and fruit gardens and is selective. Fluazifop is a post-emergent control for annual and perennial grasses and is often used for against weeds found beneath carrots and potatoes. It works by being absorbed through the leaves and roots of the weeds and gathers in the areas of the plant that promote growth stopping the energy altogether.

Lastly, clethodim is effective with grasses. It has an extremely short life span and needs lots of reapplication to work properly. Clethodim works best when applied directly onto the surface of the plant but is highly toxic when ingested and can cause severe skin and eye irritation.

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