119-133 Days to maturity. Begonia x boliviensis. Santa Cruz Sunset Begonia Seeds. Non-GMO, Annual. Santa Cruz Sunset begonias are an elegant, vibrant, yet hardy grow where other plants would decline. Santa Cruz Sunset seeds grow robust 18-24 inch leafy begonias bursting with scarlet spikes ideal for indoor planters or showing off in the flower bed. Begonia x boliviensis is easy to grow from seed and much more tolerant to drier, warmer, and diverse climates than other varieties of begonias. Santa Cruz Sunset begonia seeds promise vigorous and long-lasting blooms that are sure to add seasonal thrill to any garden or fresh-cut arrangement. Pelleted Seeds.