An attractive evergreen shrub that grows up to 2 meters, the September bush is able to adapt to most garden situations. It is fast growing, making it especially useful for new gardens. Polygala myrtifolia in the wild varies in form according to its habitat and distribution. In some areas it is a tough, loosely branched plant with relatively small, narrow leaves, while in others it is denser with larger, softer leaves. It flowers best in full sun, really dry conditions, poor soil and the least possible care - see natural habitat in photograph 6 above. Good in wild gardens, very dry gardens and exclusion zones.
The September bush will grow in most soil types. Polygala myrtifolia needs very little watering once established. It can be lightly pruned to shape, which encourages a more bushy habit and will keep it within bounds. Left to itself, growth is a bit more lax. Fewer flowers are produced in shady spots. Useful in areas that change from full sun in summer to semi- or full shade in winter.
Source: https://kumbulanursery.co.za/plants/polygala-myrtifolia