'sparse planting' is a correct and usable phrase in written English.
You might use it to describe a type of landscaping that uses few plants or trees to achieve a minimalistic look. For example, "The garden featured sparse planting of shrubs and trees to emphasize its open spaces."
Cleve West's 2014 M&G garden cleverly mixed plants that would never be found together naturally, in a sparse planting around the edges of the garden, depicting the wild on the edge of an oasis.
Quang Duy et al. (2004) suggests that a sparse planting density accompanied by small amounts of N fertilizer in the early growth stages effectively increases lodging resistance in rice plants.
You can have a rich dense garden of many desert type plants, or a more sparse planting arrangement.
In wetter areas acidic soils support forests, but the driest regions east of the Cascades have sparse plant life and require irrigation for agriculture.
It was shown that the plant populations studied were typical of a wide range of competition intensities, ranging from sparse plants to dense size-structured populations.
Achieving a one-to-one correspondence between the actual plant network and a skeleton extracted from imaging data are only possible on sparse plant networks.
Even if the fate of these sparse plants is not certain, it suggests that new weedy populations might now arise from European crop-weed hybrids and blur the information on the original introductions.
Hybrids between the cotton species Gossypium barbadense, G. hirsutum, and G. tomentosum appear vigorous and fertile, but their progenies die in seed or early in development, or they develop into sparse, weak plants.
The sparse young plants had failed to show up against the bright reflection off chalk downland.
The movement of sand by erosion is a common feature of drylands during droughts and periods of sparse vascular plant cover.
The remaining third is mainly covered by BSC, with some sparse vascular plants.
