Lilac Care wrote:a bag of miracle grow brand potting soil as mulch, which has time release fertilizer. another factor was, the lilacs was only receiving morning sunlight. the building that was blocking afternoon sun is now gone and this following year I hope will have better results. just looked at the bush a couple days ago and its only maybe 18 in. tall not 2 feet. theres probly too many suckers as you said about your own, so Im thinking thats a factor as well. really hate to clip any tho as they are spread over a 3.5 foot radius/diameter. just that at first few years after it got burned, it only grew an inch or so a year, I gave it miracle grow fertilzer and it perked up, and grew a couple inches a years. (maybe the PH isnt right) Im no green thumb. so i put a 2 yard bag of miracle grow soil as mulch hoping it will retain moisture and keep the weeds away more. yeah grass was over powering it the first few years as well. it is definitly getting better, Im hoping now that its "getting bigger" that it will take off faster. Ill post on the forum next summer and let everyone know.
WHEW! I thought you meant actual fert as mulch!!! So there's hope. Here's what I'd suggest:
1. Don't fertilize. They shouldn't need it. If you see signs in the leaves or branches that indicate otherwise down the road, then you should, but not now.
2. Full sun is definitely a plus. They'll grow in moderate sun to partial shade, but will be leggy, struggling towards light.
3. Clip those suckers! They'll come back (guaranteed). They are taking away energy that you want to direct to your main (parent) plant.
Suckers are really only good for when you want to replace a stem or two. Other than that, they sap your plant's good and eventually create a bigger issue - shade. Try to keep it as open as possible.
4. Mulch will help with the water retention, but compost will help fix the soil itself. Keep in mind that mulch, including Miracle Grow, is largely composed of wood products. As these decay, they leech nitrogen from the soil, which your plants need. By amending your soil with compost, and then mulch on top, you're golden. The compost should fix most soil issues done properly.
Follow those tips, and I guarantee you'll see noticeable improvement. Enjoy the blooms, they're a-comin'!!!