how do you crossbreed a plant without using pollen, if possible?

Answer 1

Pollen is the equivalent of sperm. It's not actually breeding without it. The idea of cross breeding is o try to get the desirable traits of the origional parents and may take several generations. Now propagation can be accomplished by rooting the cuttings of many plants but the offspring are more like clones, the are copies of their one parent. Unless you have a lab that can do genetic splicing , you are stuck with pollen to combine the traits.

Nothing else is cross breeding, it takes 2 parents, with genetic merging. Not grafting, not budding. you can asexually propagate plants, but cross breeding takes a sexual union.

Answer 2

You could maybe use a grafting technique, by making a small inscision into the 'parent plant' and the manually attaching a new breed to live through the host plant...

That's probably the closest thing to crossbreeding you could do.

Answer 3

that would be budding or grafting most likely where you take root stock from one plant and put plant stock from another on it