Forestiera pubescens (Stretchberry or Elbow bush) has still another common name, "Spring herald", because it is one of the first plants to flower in the spring. The mechanism to instigate flowering is complex; but, photoperiod (length of the night is the critical factor) is the major stimulus determining when most plants will flower. There are, however, other environmental factors that come in to play such as temperature and available water. Last summer's drought and heat were extreme and the stress they caused plants could certainly be responsible for them blooming very little then. Last year's total rainfall for San Antonio was only 17.58 inches compared to the average yearly San Antonio rainfall of 29.03 inches. Through July this year (2012) San Antonio has already had 26.64 inches with 9.84 inches in May alone. That 9.84 inches of rain is likely what triggered your "Spring herald" to bloom in summer. It isn't a very common occurence for plants to bloom out of their normal season but it does happen when there has been extreme stress during the normal flowering time and then dramatic relief of that stress afterwards. You might like to read a question and answer concerning bluebonnets blooming this year in July.
