Q.Newly planted lilacs
I planted 20 small mail-order lilacs as a hedge earlier this spring, 3 1/2 ft apart. They are about 18″ high, but the leaves seem to be small and withered, hardly any growth. They were planted in a trench with compost mixed in and watered with drip irrigation. The soil is heavy clay, but takes the water well. Comments on growth please.
Plants have a difficult time growing in clay-like soils, as it can restrict their root growth. I would recommend that you fix the soil around your plants. This article will help with that: https://www.gardeningknowhow.com/special/organic/how-to-easily-improve-your-clay-soil.htm