During 2015-2018 in the conditions of the Perm region, the seed productivity of 6 varieties Phlox paniculata L. has been studied. The effectiveness of seed production and the success of seed propagation of the phlox depend on the weather conditions strongly, in particular on the air temperature and the amount of precipitation at the corresponding stages of plant development. This is determined by the activity of insect pollinators and effectiveness of pollination. In addition, the large variability of the studied indices in different flox cultivars is probably due to their complex hybrid nature, which reduces their reproductive abilities to varying degrees.