Oleanders Struggling After Myoporum Hedge Removal

After cutting a mature myoporum hedge to the ground, a Santa Barbara gardener planted 5-gallon oleanders in the gaps. After a year, oleanders bloomed but showed no size increase.

Potential Causes

• Root competition: Myoporum forms dense, allelopathic monocultures. Old roots may physically and chemically inhibit new plants.
• pH mismatch: Myoporum tolerates alkaline soil; oleanders prefer 6.0–6.5.
• Establishment lag: Perennials often spend year one on root growth.

Diagnostic Steps

1. Test soil pH; adjust with sulfur if >6.5.
2. Dig near old trunks: if shovel penetrates easily, roots aren't the physical barrier.
3. Dig up one oleander: check for circling roots (need wider hole) or black roots (drainage issue).

Remedies

• Soil aeration/renovation around oleanders to break old root mat.
• Foliar + soil feed with water-soluble fertilizer to jump-start growth.
• If roots are circled, replant in wider, loosened hole.

Oleanders are tough; addressing root competition and pH should unlock growth.