I am thinking of placing the garden on a slightly larger lot, turning it residential and building a small home for one of my level 10 gardeners so they can plant plasma fruit. Once I have a few plants perfected, I will evict my Sim, destroy their home and turn the lot back to commercial. Then I will replace the old lots in my towns with the new one so I will have everything my Simmies want, well at least until the next EP comes out.
You can do that easier (and more importantly by keeping the small lot size for future games): just zone the garden as residential, move your level 10 gardener in (no need for toilet or bed as they will only "live" on the lot long enough to plant), have them plant the plasma fruit and move them right back out to their own place again. You may have to leave the garden lot as residential until the plants are fully grown (i had planted steak and burger plants in a sunset valley park once that would not grow to mature state unless the lot was zoned residential without inhabitants, but that was base game only, so one of the patches may have changed that), but once the plants are mature, you can zone the lot community and put it in your lot library for use in other games.
