Hi @Ash007,
Welcome to the Bunnings Workshop community, it is wonderful to have you with us.
The first thing I would try for those big weeds that your Fiskars 4 Prongs Xact Weed Puller is struggling with is soaking the soil around them to loosen things up, and then trying to pull them out with your hands.
Your weed puller is great for small and medium-sized weeds, but with those larger ones, the root ball is going to be much larger than the head of the weeder, so it won't be able to grasp the whole root ball. By soaking the soil, you will loosen it up, which will help you pull the weeds much more easily. Doing it by hand, you will be able to grasp the whole weed and pull it up, which will apply more pressure across the whole root ball than the weed puller can. With enough pressure, you should be able to pull the root ball up in one piece.
If you try this and you don't have any luck, you might need to use a hand fork to further loosen the soil around them before pulling them up.
Once those big ones are dealt with, the Fiskars weed puller should be fine for the small and medium ones, but again, if you are having trouble, try soaking the soil first.
Oxafert is a combination of a preemergent herbicide and a fertiliser, so by applying it, you are applying a fertiliser. There is no real need to apply any more fertiliser or more of your Oxafert for around 3 months after this.
Let me know if you have any further questions.
Jacob
