May. If you want to introduce a large flowering shrub to your garden within a sea of an existing lawn, make a bed which will encompass the eventual size of the shrub. This will keep the mowers in check and it will also identify the bed as an area in transition. Use temporary or transient plants as early companions to the young shrub. Over time, plants which begin to interfere with or become overwhelmed by the shrubs' growth should be removed and relocated to other parts of the garden. Plants each need room to grow and will limit the success of neighbours and themselves if planted too close together.
Annuals are excellent companions to shrubs in the early years after planting.
As the shrub grows, less and less soil is exposed and in need of vegetative cover. Climbing annuals can also decorate around and over the shrub until it becomes a focal point itself. Perennials, ground covers or bulbs can also be used, with the understanding that some will be relocated or divided at a later date. Use medium or small sized perennials within close vicinity of the shrub or use rocks and alpine plants for a temporary rockery. I find the best way to make a good selection of plants, including shrubs, for a garden is to go in to the nursery or garden centre with the location, site conditions and aesthetic needs in mind.