Make sure you don't have wood mulch on top.
Make sure you use small crushed gravel for mulch. I used small pea gravel before, but I also had enough sand in hole. I now use the small crushed limestone gravel. The size I use is #8 which I get at a local place. You can even have some of the small crushed gravel in the hole.
Make sure you use enough sand (NOT PLAY SAND) in the planting hole. I use all purpose sand from Lowe's (inside store) in the masonry isle. It's a goldish color bag and I think they are 50 pounds.
Don't use a lot of compost in hole. I think I read that on High Country Gardens website, where I get a lot of information for Agastaches and xeric plants. You should check them out and read their info.
Can't think of anything else to say right now.
