How can I remove crabgrass from a Zoysia lawn, and flower beds?

Question

We just bought a new house in Orlando. The home is great but we noticed crab grass taking over and a few other weeds. I'm a total noob with grass stuff, although I'm researching all I can.

The grass type is Zoysia.

Trugreen recently came and did their application for the lawn but they said they couldn't do anything with the crab grass. I went and bought round up. I was planning on to spray all crab grass invested areas and then probably lay sod or just reseed? I'm not sure if you can just throw seeds in there. (Total noob).

Also, I have flower beds in front and back of the house. I wanted to put stones in there and do some brick edging. There are weeds there as well. What is process of cleaning that out? The guy at Home Depot told me to dig out the weeds, spray some round up, put a weed mat on top and then cover that with fresh top soil and then plant my new plants and go from there whether I wanna do mulch or stones.

Am I on the right path? Please advise.

Answer 1

Re the flowerbeds, yes, you need to dig them over and extract all weed roots, preferably without leaving any behind. The guy at Home Depot's advice was incorrect though - if you want to use Round Up, that works 'through the green', which means it needs to be applied to strongly growing green growth when the soil is damp. Applying it to roots or bare soil does nothing other than cause a bigger residue of Roundup in the soil.

He's also wrong about how to use weed membrane - if you want to use it, lay it after you've dug the beds over and let them settle, having left enough time for any regrowth of weeds to show itself so you can dig that out too. Once you've laid the membrane, you will need to make cuts or slits in it and plant through those, so the roots of your plants are in the soil of the bed beneath, and the topgrowth above the membrane. That can be a pain if you like to use temporary plants for summer - every time you want to replant, the membrane will be in the way. After planting, cover the membrane with some type of mulch, such as bark chips or similar, or an inorganic mulch such as the stones you mention. Alternatively, don't use membrane at all, just rely on hoeing out any weeds as they appear on a regular basis around any plants you've put in. If you choose not to use membrane, then it would be better for the soil and your plants to use an organic mulch rather than stone. Membrane isn't a perfect solution - some weeds are difficult to get rid of and keep regrowing under the membrane, and other weed seeds germinate in the mulch layer and grow there instead, so sometimes its easier to just keep hoeing, so think about which you'd prefer to do.

As for the grass problem, there are, I believe, herbicides which kill crab grass - I'm not sure if Round Up does, it should say on the pack. Once you've killed it, you need to read the directions on the products you've used - there will likely be a gap or length of time from use of the herbicide and when you're able to reseed or lay sod, so wait the required time. When it comes to reseeding, you will need to create a fine tilth on the bare soil (that means a fine, crumb like structure for the top inch or two), then sow into that. This fine tilth is also necessary for sods to root into easily, but take care that the level you lay the sods at is one that matches up with the rest of the grass.

Answer 2

I am glad you asked us rather than listen to True Green and Home Depot. My goodness! Please PLEASE forget that plastic membrane!! Please. It is one of the dumbest things us humans have done...I've made tons of money ripping this stuff out. It causes far more headaches and does zip for weeds.

Any mulch like bark mulch should be as fine as you are able to procure. You need to read my stuff on the best mulch in the world...not available everywhere. But a big big wow to the point I would not use ANY OTHER mulch would not accept clients who had to have 'bark'...period. Never lost a customer. Gained hundreds when they saw the results.

Zoysia IS a major weed. Which like most 'weeds' is short, short rooted, able to reproduce vegetatively as well as by seed and is able to out compete all else.

You can get rid of grass weeds in your lawn but it is done very carefully. Paint brush. Plastic skirting. This is not plastic 'weed fabric'!! This is temporary for the job. Paper towels. No rain in future. Latex gloves. Slip clean 3X3' plastic with hole for weeds to protect Zoysia. Dip brush OR plasticized fingertips into glyphosate. Gently paint vigorous weed leaf growth. Doesn't take that much. A single drop of glyphosate will kill any herbaceous plant down to the roots.

In other words, do not spray! Just paint a few leaves of the weed and carefully move to another spot to paint the weeds. Never allow weeds to go to seed. That is the biggest prevention or control of weeds in warm season grasses.

Use sharp blades on your mower. Clean blades each and every time with alcohol when you mow. Bag your clippings I kid you not! In one season maybe two you will get rid of crab grass. Glyphosate is highly recommended because when you paint that stuff on the leaves it is translocated to the roots. If you pull crab grass, well, every little piece that breaks off will make a new plant. You want to kill the roots. Glyphosate kills the roots. After painting the leaves, wait 3 weeks. Any crab grass that you missed will be easy to see. Paint that...this will take some time. A good month?

There is no better way to get rid of a grass weed within a grass crop. Glyphosate changes composition the instant it touches plant or soil. It will not leach. It will do its job and you can forget about hurting 'the planet'! More to this story but for now this advice will work just fine. Ugh. True Green...hey anytime you have someone come to your home to use pesticide or even fertilize, insist on seeing their licenses!! If stuff dies...they are responsible firstus. They should also post signs! That is part of their licensing...gee, I know cause I have been a commercial licensed pesticide applicator for 30 years!! Just ask for licenses! That is a big deal. Every single person that uses any chemicals on your property has to be licensed! Even Joe that lives a block away! For his own protection as well!

Answer 3

For your lawn:

1. You can use a selective herbicide to target the crabgrass. Make sure your product is safe to use on Zoysia. I use Quinclorac based herbicide, because I find that Zoysia is highly resistant to it, once established. I know of some people who use Monosodium methyl arsenate (MSMA) based herbicides, but if you do that, be careful, because some zoysia strains are more sensitive to it than others, and do not use it if the temperatures will go over 70 F for the next 8 days or so. I know Florida has stricter herbicide use laws than we do here in PA, so I'm not sure what you can get your hands on. A selective herbicide will save you the trouble of having to replug a Zoysia lawn, which is what you would have to do if you use a broad spectrum herbicide like glyphosate.

2. After that, you can seasonally keep the crabgrass at bay using a zoysia safe pre emergent herbicide such as Pendimethalin, and spot treat what comes up anyway, with a selective herbicide.

3. Zoysia will quickly fill in small gaps in the turf, if it has been severely thinned by the crabgrass in some areas. If there are areas greater than 18" across, which are completely diminished from Zoysia, you could consider purchasing some plugs, or pulling plugs from your existing turf, to help fill the gaps quickly.

For your beds: '

1. If there aren't many plants in the beds, pull the weeds from under the plants, trying to remove as many roots as possible, then weed whack the open spaces. when the weeds begin to regrow, spray them off with glyphosate. If the beds are densely planted, you might just have to dig all of the weeds.

2. Once the weeds have yellowed, you can put in your new plants, if you have any.

3. You can then apply a granular pre emergent herbicide (I use a product that blends Isoxaben and Trifluralin, which are tolerated by most ornamentals, and will last all season - very efficient). Again i'm not sure what is permitted in your area.

4. You can then put down 3-4" of organic mulch, and you'll be all set. I don't recommend putting plastic in.