When it comes to feeding my lilacs, what/when should I feed them.
Dear Gardener: It is best to feed Lilacs after bloom until mid July. Feeding after mid July, might produce new growth that might not have time to harden off before cold sets in. However, Lilacs are not very demanding plants and usually do not need much care after they are established if they are in good soil and mulched. However, a fertilizer which is not for acid loving plants such as 5-10-5 would be fine: lilacs like soil that is neutral to on the alkaline (lime) side.