schreef
Considering the difficulties of building a transparent structure that
is strong enough to resist vacuum and meteorites on the moon, I think
it would be much more practical to have surface solar collectors to
generate electricity to power lights to grow plants. Obviously, you'd
need some method of energy storage for the lunar nights, but growing
crops under artificial lighting is a solved problem. For example,
vegetables have been grown in deep mines in northern Ontario, taking
advantage of the natural heat at depth and the cost of supplying
vegetables in reasonable condition to remote areas with too short a
season and too little heat to grow them on the surface profitably.
IIRC, these projects mostly produce tomatoes and cucumbers, but there's
a lot of developed technology for growing lettuce in surface
greenhouses with supplemental lighting in winter at higher latitudes in
Europe where less supplemental heating is needed in such structures
than in Canada.

Note that your lunar garden provides the valuable function of removing
CO2 from the air as well. Many plants grow better in elevated levels
of CO2, and it's sometimes used commercially to increase growth in
greenhouse lettuce crops, usually by burning propane.

Btw, you might consider how else this lunar colony is getting its
energy. Is it all solar, or is some derived from e.g. a nuclear
reactor? In the latter case, there may well be plenty of energy
available to power lighting for plants.

* * *
Yes, I did not think this through. All things being equal the total amount
of assimilates will be the same for every day = light+dark-period
(photosynthesis going on until the cut-off point is reached by water
shortage), but respiration (per light+dark-period) will increase 28-fold and
the plant will die.

Of course it is entirely academic, as any kind of structure built on the
moon that would keep out a vaccuum would also alter just about all the
circumstances. A meaningful answer is not really possible. Almost certainly
some kind of artificial lighting scheme would be put in effect (perhaps
something involving mirrors and satelites?), almost as a matter of course.
PvR

A Science Fiction book from the fifties will likely go into the matter more
deeply. I remember one of them speculating on the effect of 'virgin' moon
soil on plant growth.