Expanding Dead Zone in Kansas City Garden: Systematic Diagnosis

Pattern

North-side spot kills everything in 2 years: azalea, columnar juniper, dwarf pine, elephant ears. Spot enlarges yearly. Soil vs. disease vs. toxin?

Diagnostic Checklist (In Order)

1. Sun mismatch: Azalea needs shade; juniper/pine need 8+ hrs sun. If shady, sun-lovers die. If sunny, azalea dies.
2. Moisture extreme: Elephant ears want wet; others need drainage. Dig 12×12 inch hole, fill with water. Drains in <2 hrs = OK. Stands = wet. Dry in 1 hr = dry.
3. pH test: Target 5.5 for listed plants.
4. Gas line leak? Mercaptan odor, dead vegetation line.
5. Disease unlikely: Few pathogens kill such diverse hosts. If 1–4 negative, try broad-spectrum soil fungicide as precaution.
6. Toxin screen: Plant grass, spinach, morning glory seeds. If all die, suspect herbicide/petroleum residue. Full lab analysis needed.
7. Voles/moles: Voles use mole tunnels, eat roots. Check dead plant roots for gnawing.
8. Mulch issues: Must be aged, ≤2 inches, not touching trunks.

If All Negative

Send soil/root samples to state university diagnostic lab or private analytical lab for complete chemical/biological analysis.