My sister said you need two gardenia plants to grow or produce flowers, is this true?

Welcome to NGA @Burningtoday

Perhaps that would be necessary if you were looking for fertile seeds, but I see single beautiful ,huge gardenias in full bloom with no other gardenias in sight. Mine blooms all by itself.

Here is some general info for you,.

http://garden.org/plantguide/?...

http://www.southernliving.com/...

I only have a single plant and I know there is not another gardenia in sight. Mine blooms every spring.

Hi & welcome!

Always interested in learning something new but as of today I don't know of any kind of plant that requires 2 individuals to produce flowers. Some kinds of plants are monoecious, meaning that individuals are either male or female, and one must have one of each for pollination to occur. Some of the male or female blooms of these might be so inconspicuous as to be overlooked. And, as Jean was saying, some plants require separate individuals for pollination to occur (self-sterile.)

But, a lone Gardenia is an unnecessary thing unless space is really tight. The only thing better than 1 Gardenia is more Gardenias. :+) You can snip a branch off, keep it moist in the ground (and a lawn chair over it for shade the first couple weeks can help,) and it's more likely than not to take root and grow a new shrub. I've had worthwhile success doing that. A couple I did 2 summers ago are blooming.