May 2020
@G1gi The option appears only for the new seed, not the plants that are already planted.
March 2022
I'm having this same issue. All new plants an the water option still doesn't show up at the science lab. My sim has a home garden and is able to water plants there. Newly planted plants can't be watered and don't grow because of it at the science lab.
June 2022
it's been FOUR YEARS and this isn't fixed?