Underlining is a layer of builders’ sand or matting that is put over the soil when a pond is being constructed. It is an extra level of protection to prevent sharp stones from making holes in the pond lining.
Underplanting is a method of planting low-growing plants underneath taller shrubs and trees, to fill gaps and areas of bare soil. Underplants are often shade-loving plants that are hardy and drought-tolerant, such as Epimedium.
Plants that are described as ‘upright,’ or of an ‘upright growing habit’ generally have stems and branches that grow upwards vertically, as opposed to spreading outwards, climbing, or growing up and out at the same time.