How to keep grass weeds out of garden beds?

Question

Hello,

I have what appears to be an extension of my lawn growing into my garden beds. I have tried manually removing it but the root system is quite deep and it inevitably grows back, can anyone suggest a product I might be able to spray to keep it at bay (ideally without harming the Magnolia's)?

Also looking for any suggestions on how I can revive the Magnolia's that aren't looking too healthy. The leftmost seems fine but the other 2 always have less leaves. Related to the grass weeds perhaps? Could they also do with a pruning?

Any assistant is much appreciated.

Noyade · Answer

I like to build a fortress (treated sleepers), lay down that mat stuff and fill with graded bark. My new camellias are going well and look - I even managed to grow a new gas meter overnight!

JacobZ · Answer

Hi @tjwg,

My thinking is pretty much along the lines of @Dave-1's here.

Your magnolias look to be in pretty good shape, and they look about how I'd expect them to when nearing the end of winter. I'd give it a few weeks before you do anything with your magnolias. It is best to be sure that the cold weather has passed before pruning or taking any drastic action. You will likely find that things bounce back well once the warmer weather kicks in and they start actively growing.

Right now, you could go through and remove any dead branches and tidy up the soil around the base of the trees. Check out

https://www.bunnings.com.au/diy-advice/garden/planting-and-growing/growing-pruning-and-caring-for-magnolia-trees-magnolieae

for some further guidance.

With the grass, I'm with Dave that the best thing you can do is manually remove it. The only herbicides that will kill grass are non-selective, meaning they will also kill any other plants they come into contact with, which just isn't worth the risk in close proximity with your fantastic magnolias.

My suggestion would be to first tidy up the soil by raking up the old leaves and mulch, which can be used to create compost or simply disposed of, then manually remove as much of the grass as possible. You can then use a garden fork, mattock or hoe to gently turn the soil and remove as much of the remaining grass as possible.

I'd then suggest applying a good thick layer of mulch, at least 70mm thick to the entire bed. This will help your soil with moisture retention, warmth and most importantly, will help to suppress unwanted growth from grasses and weeds. There may still be some poking through, but it will be limited and can be managed by simply pulling it out as it pops up.

You might also consider digging installing a root barrier alongside the existing garden edging. It would be buried much deeper, which will make it more difficult for the grasses underground runners to find their way into the garden bed.

Ultimately, weeds and grasses in garden beds are an ongoing thing. No one action will eradicate them, but with a good layer of mulch, a root barrier and some persistence, you should be able to keep it at bay with much more ease.

Let me know what you think and if you have further questions, please don't hesitate to ask.

Jacob

Dave-1 · Answer

Good Morning @tjwg

Looking at your photos the Magnolias dont seem to be in too bad a condition? Can you snap/bend one of the leafless twigs on them? We are coming out of winter and Magnolis do loose their leaves over winter unless they are in a shelterd spot as yours could be. If the twigs bend then Id say its happily growinga way waiting for spring. If they snap (depending on how many and how far down they snap) could mean something that should be looked into. I think its going to be flexible twigs :)

As to the grass encroaching into the garden bed, I prefer weeding it out. Harder work but I dont like the idea of using pesticides. With springa round the corner I would wait until someone who knows more so what can be used under a magnolia to kill grass when it is peak growing season.

I would also lightly scracth up teh soil surface. It looks overly damp and maybe compacted. I would also redo the gatrden edge as it will help keep the grass out of it.

Your garden looks pretty good for coming out of winter. Id wait a little longer before feeding it anything and just keep an eye on the level of water/dampness you have.

Dave