chula said:

We are planting heirloom varieties this year and are planning three
different types of tomatoes (beefsteak, roma and one other). Our
garden plot is small and even if we plant them all as far away from
each other as possible I would say there will be less than 4 feet
between varieties.

Will these three plants "interpolinate" creating a non-standard variety
from the seeds next season? Hubby seems to think this is inevitable
since the plants are so near to each other.

I remember reading about a study done in South America which showed
that the natural hybridization rate for tomatoes was actually quite low.

But it can certainly be *prevented* in the home garden by bagging
selected trusses to prevent insect visits. You should shake the bagged
trusses to ensure self-fertilization. Once the tomatoes have set, remove
the bag and mark the truss with a bit of bright yarn or ribbon.

--
Pat in Plymouth MI ('someplace.net' is comcast)

Any technology distinguishable from magic is insufficiently advanced.
(attributed to Don Marti)