There are 22 plots and 41 types of collectibles (17 kinds of food, 12 kinds of plorts, 12 slime science materials).
Assuming you want to have a hoard of each item just for the sake of having a collection, you only need to put silos in half of the available plots. If you can select one item to not hoard (like pink plorts that you can always get more of) or if you don't want to hoard slime science mats, that frees up another 1-4 plots That leaves you with 11+ plots to corral slimes and grow food, which should be plenty to let you do sustained farming for extractors. Just grow one resource at a time in several plots to fill up your collection, then stop bothering with that resource once the silo spot is full.
This sort of collection is one among a couple of ingame goals that takes over most of your farm, so if you also wanted, say, a zoo of every type of largos, you'd be having a lot of issues, but just the item collection shouldn't be too much of a space concern.