How to rid plants of grass?

Shoxt3r · June 2019

Hi there,

We've been having quite a battle with grass growing inside various shrubs in the garden and despite keeping tabs on it by pulling it out the grass comes back within about a week or so.

We regularly water the shrubs which probably encourages the grass but is there a way to combat this without affecting the shrub itself? Picture below...

Thanks!

kenneth.green2009 · June 2019

The way I would tackle this depends on your feelings about chemicals. I do not use them unless I have no choice but I am sure that there will be one that will kill the grass but not the shrub (Please wait until someone with more knowledge on this comes along). The way I would personally tackle this is to carefully dig the shrub up (try not to damage the roots) and then under a running tap or hose wash off all, or as much of, the earth as you can. Then you should be able to clearly see the grass shoots are roots and can carefully pull them out.

hogweed · June 2019

Ditto the above although I had to do that with some geums this year. However I split the clump and potted the bits up. Glory be if the grass is still not coming! Should be an easier job with the hydrangea - just be careful you pull the roots out with the grass and keep an eagle eye on it for the rest of the year.

JennyJ · June 2019

I'd do the same while the shrubs are still small (in fact I did it a few years back with a ceratostigma)

B3 · June 2019

There's probably just a few actual grass plants there. You haven't any thorns to worry about on the hydrangea so I'dhave a poke about at soil level and see of you can pull most of the grass plant out at once.

Helix · June 2019

I obviously come from a different school! I would never dig a plant up just to remove grass. Instead I would carefully tease out the grass roots while the plant is in place using my fingers and maybe a handfork. Can take a while to do carefully, maybe 30 minutes or so, and easier to do if the plant is well watered. Just tugging the top of the grass off won’t do anything.

If that doesn’t work then dig it up in the autumn. But if you do it now you are likely to lose the shrub.

And I can’t think of a chemical that would kill grass and not the shrub, as the selective ones are usually the other way round!

Fairygirl · June 2019

I'd also make a better defined edge to the grass, and then weed the border properly. There's a lot of weeds in there generally.

After watering you can then apply a mulch of compost/bark/shingle [whatever's your preference] which will help suppress weeds until that hydrangea gets bigger. I'm afraid weeding is a normal part of gardening, and needs doing regularly.
You could also consider some ground cover planting around the hydrangea until it's a decent size.
If it was mine, I'd lift it and remove the grass. Much easier than trying to get in among it. If it's thoroughly watered before and after [ie really soaked] and kept weed free, it shouldn't bother it at all. It's tiny.

JennyJ · June 2019

I seem to remember there used to be a selective weedkiller for grass that didn't kill broad-leaved plants but I think it got withdrawn/banned. Not much use to answer the question though.

I de-grassed my Ceratostigma sometime around late May/early June several years ago (it was couch grass so pulling from the top was never going to work), planted it in a big pot afterwards supposedly temporarily so that I could keep an eye on it for grass regrowing, and it's still in the pot and doing well (forming flower buds just now). You just need to keep things well watered and sheltered from strong wind/hot sun while they settle back in.

Joy* · June 2019

I've had the same problem and have dug up the whole plant and tried to remove ALL the grass roots. The trouble is that even if you can pick them out of the plant roots you are rarely able to get every bit out of the soil. When you put the plant back, the grass grows again. I would put the hydrangea in a pot and aim to clean all the grass out of the border before planting anything. Unless you choose to use chemicals to do this, the pot could sit on the bare soil. Looking at your photo it appears that the hydrangea isn't the only place there is an infestation of grass. You might have to clean a large area to remove all of the roots. Once grass gets going, the roots can travel long distances and even bits 10mm long will grow.

Hostafan1 · June 2019

There was indeed a "couch grass killer" which could be sprayed over broadleafed plants. It worked a treat and didn't harm the plant, but ,as has been said , it's not available now.

How to rid plants of grass?

Posts