My Wife like lilacs, my yard is heavily loaded with Clay soil you can dig over 4 feet anywhere and still hit solid clay. I thought that might be causing premature root rot. Any suggestion on planting a lilac in this type of soil or are we just not going to be able to plant one? Previously I have dug a large hole much bigger than the plant I am planting, added crushed stone to the bottom, then filled it in with good topsoil mixture and then planted the lilac.
First make sure that the area gets a MINIMUM of 8 hours of direct sun per day…more is even better. The dig your hole wide like you have been but not so deep. Dig it only deep enough that, when you place the root ball into the hole, about 1/3 of the root ball is ABOVE grade. This will allow the root system to breath even if the lower part of it is sitting in soggy clay soil below. Don’t add gravel or any other amendments to the soil other than Espoma Bio-Tone Starter Food. Gravel will not help in this situation. Naturally you’ll need to watch or dry weather and keep it moist during dry spells. After a few years, it should be self-sufficient. Lilacs can and do grow in clay soils.