Frycook posted this fascinating video from the Apollo era on the BoingBoing Submitterator. The basic gist: Back in the day, NASA scientists tried exposing various crops—corn, lettuce, tobacco ... you know, the essentials—to moon dust. The plants weren't grown in the dust, exactly. Instead, it was scattered in their pots or rubbed on some of their leaves. In this study, the plants that were exposed seemed to grow faster than unexposed plants.
That's pretty interesting, so I dug around a little to find out more about these studies. Turns out, growing plants in lunar soil isn't quite as promising as the video makes it sound, but it's not a ridonculous idea, either. In 2010, scientists at the University of Florida published a review of all the Apollo-era research on this subject, which amounted to exactly three published studies. From that data, we can say that the plants weren't obviously affected in any seriously negative ways by their exposure to lunar soils—which is good—but we can't really say the plants grew better their terrestrial-only cousins, either.
In the end, and as recorded in the peer-reviewed scientific literature, there were only three published primary studies of seeds, seedlings, and plants grown in contact with lunar materials. In those three cases, small amounts of lunar material were used, and the plants were relatively large. In general, the dusting of plants or the mixing of lunar fines with other support media makes plant interaction with the lunar material a small part of the plant experience. At no point were plants actually grown in lunar samples in the way that one might imagine, with the entire root structure growing through and in constant association with a lunar soil. It is no accident that the wording of most of the titles of the studies, as well as the careful discussion within the papers, refers to growth “in contact with” lunar samples—not “in” lunar samples. With only a small portion of the roots, for example, interacting with the lunar materials, it is likely that plant responses to the lunar materials were, therefore, quite attenuated due to the lack of an extensive plant/lunar soil interface. Biophysical issues, such as root penetration of dry and variously hydrated lunar sample types, were completely unaddressed. Thus, the effects of actual growth within lunar soils were simply not a part of the plant studies of the Apollo era.
On the other hand, in 2008 scientists with the European Space Agency tried growing marigolds in a medium of crushed rock—basically the much-cheaper equivalent of growing plants in moon "soil". There's no indication that the marigolds did better than those grown in real dirt, but they did grow and they did survive (even without any added fertilizer), which could be indirect evidence in support of the Moon gardeners of the future.
Read the 2010 review paper—available for free, in its entirety