 The strongest matrices consist of a succession of layers of vegetation through which sunlight filters, until at ground level there is enough only to support plants that can cope with very little light.The best examples of such matrices occur in deciduous woodlands, but that does not mean all gardens have to become micro-forests—effective matrices can also be formed by shrubs and perennials in mixed borders.Some may argue that matrix planting is just another term for ground cover, but matrix planting is concerned with successive layers of vegetation, one above the other, through which plants form multi-dimensional communities.