More information is understood about animal species than about plant species. And it is generally assumed to be reasonable that there can be some similarity between plants and animals at some level.
So this predisposition of sex is a hot topic among zoologists and breeders. Here is what they found.
Some species, like alligators, can have more or less of a sex by altering incubation temptiture. Birds, in some cases, seem to follow the same pattern. However, some species seem not affected by outside influences.
I received that information from a well known bird veterinarian.
Since pollen has no subtle differences in appearance (i.e. male pollen or female pollen) I would speculate that environment has at least some part in determining the sex of the offspring. If you go back to the example of alligators, regardless of the environmental changes, you never get completely male or completely female, offspring from a clutch of eggs.
So, I believe, "feminized" is a generality, not an absolute.