can someone please offer some advice we’ve put down cardboard all new soil plus fine mulch, and the weeds have come up everywhere still can anyone suggest how we can stop weeds from coming through
Hi @emmawigg,
You’re on the right track; those are good steps so far.
The main thing is that when using cardboard to suppress weeds, you usually need quite a few overlapping layers to properly block light, and the mulch needs to be fairly thick to be effective. If either is a bit thin, weeds can still push through pretty easily.
From here, I'd suggest you hand pull the weeds while they are still manageable, or spot spray with a non-selective herbicide such as https://www.bunnings.com.au/ocp-1l-slasher-weedkiller-concentrate-1l_p2962229 .
Once the weeds have been managed, you could pull back the existing mulch and add a few more layers of thick cardboard or some weedmat, then top up the mulch to a thicker layer, around 75 to 100mm. The added thickness will help to suppress weeds that lay dormant in the soil.
Unfortunately, weeds will always try their luck, especially with fresh soil, but once you build up a thicker barrier and stay on top of new growth, it should become much more manageable.
Let me know if you have any further questions.
Jacob
