Heirloom seeds are from plants whose flowers self-pollinate
First, there is an impressive body of literature that shows that many orchid species self-pollinate
when pollinators are rare or absent (Burns-Balogh & Bernhardt, 1988; Catling, 1990; Neiland & Wilcock, 1998).
Sweet peas self-pollinate
just before the flowers open and so no cross-pollination can therefore take place.
Unfortunately, very few tillandsia species will self-pollinate
if you have only one plant, or offsets that originated from the same plant (i.
So even if the plants self-pollinate
, you can get different and interesting flowers.
Others, like tomatoes and raspberries, can self-pollinate
but produce more, larger, or better fruit with the help of pollinators--in the case of tomatoes, 45 percent more fruit compared to self-pollination alone.
In a different study, Abronia umbellata breviflora, however, was observed to self-pollinate
and set viable seed in a greenhouse (McGlaughlin et al.