Hi, Barb: What a nice part of Canada! It sounds like you need to go back to square one and test your soil’s pH. Lilacs like 6.0 to 7.0, which is basically neutral to slightly alkaline. Add a little lime in the spring and again in the fall only if you find the pH lower than 6.0. If you find that your soil has become too alkaline, replace some with neutral soil to reduce the downward leaching of the alkalinity. Slowly but surely, bring your soil to the proper pH. Also, make sure that your soil does not have too much nitrogen, which can sometimes happen due to fertilizer runoff. Finally, lilacs need 6 to 7 hours of sun each day for best blooming, so make sure that yours isn’t in too much shade. Good luck!
Hi, Barb: What a nice part of Canada! It sounds like you need to go back to square one and test your soil’s pH. Lilacs like 6.0 to 7.0, which is basically neutral to slightly alkaline. Add a little lime in the spring and again in the fall only if you find the pH lower than 6.0. If you find that your soil has become too alkaline, replace some with neutral soil to reduce the downward leaching of the alkalinity. Slowly but surely, bring your soil to the proper pH. Also, make sure that your soil does not have too much nitrogen, which can sometimes happen due to fertilizer runoff. Finally, lilacs need 6 to 7 hours of sun each day for best blooming, so make sure that yours isn’t in too much shade. Good luck!