Question
There is a problem spot on the Northern side in our Kansas City (midwest US) garden. Every single plant dies in that spot within 2 years. We have lost beautiful pink azalea a couple years ago; a tall columnar juniper turned completely brown this year, causing juniper-raw design problem; also a dwarf pine is in the process of turning brown/dying. Even "elephant ears that I planted this spring, have brown spots on some leaves and some leaves completely brown. Is that a soil problem or any kind of spreding desease? Looks like this "dead spot" get larger and larger every year.

Any kind of advise would be highly appreciated! Thank you in advance.

Virginia

Answer
Hi Virginia, Here's a list of potential causes...
1. Sunlight - Azaleas are shade lovers, the other plants are sun lovers (8 or more hours). If this is a shady area, the azalea may have died from an unrelated cause, the junipers from the shade.
2. Elephant ears like water, the other plants need excellent drainage, so is this area either too wet or too dry? Dig a 12" x 12" hole and fill it with water to see if it's draining properly.
3. Check your pH. For all the plants you listed, 5.5 should be best.
4. Is there an underground gas line that could be leaking?
5. It's probably not a disease. Most diseases don't attack such a wide variety of plants but if you can rule out most of the above, then I'd treat the area with a soil fungicide per label instructions just as a precaution.
6. Can you rule out soil toxins such as herbicides or petroleum products, oil, etc.  Without a complete soil analysis it's hard to be sure. You might plant a few seeds of grass, spinach and morningglory and if they all come up and die, then you may have a toxin.
7. Look for evidence of moles and voles. Moles don't eat plants, but voles will use their runs and they can destroy the roots. Inspect the roots of the next plant that dies.
8. Mulch...be sure it's aged and never more than 2" deep. It should never touch the trunk of the plant in the summer.

These are the most common causes.  If the answer's not here, then I'd send a sample to an analytical laboratory or your state university to look for a cause.  Jim