How to Grow an Australian Mint Bush

The Australian mint bush (Prostanthera rotundifolia) gets its name from its native country and its mint-scented leaves. The evergreen shrub grows about 6 feet tall and wide, and in the spring it is covered with small pinkish-purple blooms. Australian mint bush grows best in full sun or light shade, and multiple bushes should be spaced 3 to 4 feet apart. Grow the shrub in U.S. Department of Agriculture plant hardiness zones 9 through 11, but don't be afraid of frost as Australian mint will survive a 20-degree Fahrenheit overnight cold spell. They need a well-draining soil and do best in a rich loam. The mint bush does best in a slightly acidic to neutral soil with a pH between 6.0 and 6.8 but will tolerate alkaline soil.

Slow-release fertilizer
Pruning shears
Insecticidal soap

Instructions

- 1
  Water the mint bush at least 1 inch per week. Watering deeply, then allowing the soil to dry slightly before watering again, is best. Established shrubs are drought tolerant, but they should still need supplemental water in the summer.
- 2
  Add a slow-release fertilizer when the shrub blooms. Sprinkle 1 cup of fertilizer over the root zone and mix it into the top inch of soil. Water the fertilized area.
- 3
  Prune if needed after the blooms fade. Cut no more than one-third of the Australian mint bush at one time. Do not cut past the leafed part of the branch. Make cuts just outside a leaf set, bud or lateral branch to promote new growth. Remove dead branches back to the base of the branch at any time of year.
- 4
  Watch for pests such as aphids or mites in the summer. Check the undersides of leaves for tiny moving specks if there are spots or holes in the leaves. Wash the shrub with a pressurized spray of water to dislodge the insects. If they persist, spray the foliage with a premixed insecticidal soap spray.

Blooming of the Forsythia

Salt Tolerant Bushes for Zone 4

Shrubs