Picking. Then red ones inked up and that hunger Sent us out with milk cans, pea tins, jam-pots
The lust question gets answered pretty quickly. They're only after the berries.
The "you" mentioned near the beginning has now turned into "us."
Line 8 means that seeing the very nearly ripe ones gets them psyched to go picking because they know the time is right and that these berries will be ripe soon.
They go out with any container that will hold the berries – way to recycle!
Line 10
Where briars scratched and wet grass bleached our boots.
They're going off the beaten path for these berries, even hunting around thorn bushes.
The wet grass might be from the rain we learned about in the first line or perhaps it's dewy and early in the morning. Either way, their boots are getting a little wet.