As temperatures rise in our gardens, we should think about plants that can take the heat. Often these plants have the added benefit that they are drought-tolerant once they get established, explains Jenny Rose Carey, Senior Director of PHS Meadowbrook Farm.
Some of us garden in rocky soil or in sandy soil at the Shore – these plants are perfect for those conditions. Others garden in heavy clay where there is too much moisture around the root zone for these plants to thrive. In that case, place these plants in a raised area and amend the soil by adding rocks, sand, and gravel to increase drainage in the flower bed.
Jenny Rose recommends these rock garden plants, which thrive in dry, low-fertility soil and full sun:
- Armeria maritima – Sea Thrift. This is a tiny cushion plant with fine, grass-like foliage. In the spring, round, pink or white flowers pop up on stalks held above the leaves. This is a great plant for the front of a well-drained border. Like many other dry-loving plants, it will be killed by water sitting around its roots or by too much fertilizing. Cut off the flower stalks after flowering and there may be a few more blooms.
- Dianthus – Pinks. Gardeners have grown pinks in their gardens for hundreds of years for their sweetly scented, fringed blooms. The flowers are often pink in color and they emerge out of a low mound of silver or greenish foliage. There is a wide selection of plants to choose in this genus. It includes tiny mounds that can be grown in a trough, or rock garden and larger species that are perfect in a well-drained part of a flower bed. Do not water these plants on a hot day or soak the foliage as the plant will die. Deadhead the plants when the flowers have finished. If it is a large plant, use hedge shears to cut them off.
- Eryngium – Sea Holly. These are not true hollies, but a silvery, spiny herbaceous plant that is perfect to add variety to your flower garden. There are a few different species and cultivars available, but they all have a ball-shaped flower head surrounded by a star-shaped ruff. This is great in the garden and as a cut flower. This plant is drought tolerant due to its tap root, so it does not transplant well. There is a sea holly that is native to the southeastern U.S. called Rattlesnake Master or Eryngium yuccifolium. It has a spiny flower but without the ruff. At 3 to 4 feet high, it is too tall for a real rock garden, but it is perfect for an area of your garden where you do not want to water. Add a gravel mulch around the roots for extra drainage.