Why does my forsythia bloom poorly and often has blooms in october . l live in zone 5 in pa
Do you prune your forsythia annually; it blooms poorly on old wood. Remove 1/3 of the largest diameter central branches to the ground in spring after bloom time. Pruning after July 4th will drastically reduce next year's bloom. Forsythia also requires full sun for best bloom. The wild card is the weather. A warm spell in March followed by a return to freezing temps can ruin flower buds. Sporadic bloom after an early autumn cold snap is not uncommon.