There are 2 parts for the Foraging Machete quest: fertilizer and rare plants.
Fertilizer Quest:
3 Owlbear Dungs
3 Fungust Composts
2 Netherbian Nitrates
Rare Plants Quest:
1 Twilight Orchid
1 Dawnflower Seeds
1 Red Sands Cactus
1 Letalis Zenith Vine
In Katta Castellum, you speak with Tobala Honeyjar and you can choose which one to do. If you choose the fertilizer, she gives you an "empty fertilizer bag" and that where you put the components and "combine" to make a no-fail "full fertilizer bag.
If you do the Rare Plants quest, you go to different zones (scarlet desert, twilight sea, mons letalis, dawnshroud peaks) and forage very rare items. It can take up to or over 3 hours to forage one or all of these items, with a foraging skill of approx 180.
Anyway, after you give her the full fertilizer bag she'll give you a stat enhancing grub. then after you give her the 4 other items, she gives you the foraging machete.