How come some seedless plants reproduce only asexually during dry times of the year?

Some seedless plants reproduce asexually during the dry times of year because the factors which helps to asexually reproduce seems to be unaffectionate in the wet seasons.

As the asexual reproduction involves the transfer of pollen grains or spores or vegetative propagation. In the wet seasons the transfer of pollen grains seems to be harder. Some affecting factors are:-
The winds do not blow harder
Rain comes with the wind to drop the spores and the pollen grains in unfertile area
Animals who helps in transfer of pollen grains tend to stay at one place most of the time
But as speaking of the dry season, the wind blows hard, animals walk around much, which help the pollen grains or spores to get their destined place.