Whether your dry riverbed of rocks, stones and/or gravel is for drainage or a meandering path through your garden, plants can add visual interest year round and soften what can be a harsh, hot landscape. To acquire a unified appearance and enhance the “look” of a river or stream, plant “drifts” in odd numbered groups of the same plant rather than planting a hodge-podge of plants.
To reduce the amount of maintenance required, plant low-lying, mounding evergreens, flowering perennials and bulb plants that are sun tolerant. San Jose, Bar Harbor and Blue Rug are examples of low growing evergreen junipers that will spread and mound gracefully on the perimeter of the riverbed. For spring color, plant Narcissus (daffodils), a low growing bulb and/or Iberis sempeavirens (candytuft) whose white blooms will spread over the rocks, making an excellent border plant.
Select easy-care, heat and drought tolerant perennials such as Pavonia lasiopetala (rock rose), a Texas native, or Tagetes lucida (Texas tarragon) also known as Mexican tarragon, a pest-resistant herb with clusters of golden yellow flowers in the fall. Lantana montevidensis (Trailing lantana) is a spreading perennial that is very heat, wind and drought tolerant, and comes in lavender, purple or white flowers which bloom from spring to frost providing color to contrast with the stones of the riverbed.
Sages are excellent choices to add color and variety within the riverbed where varied height is desired. Salvia farinacae (Mealy Cup Sage) with varieties of blue, white or purple flower; Salvia greggii (Autumn Sage) produces flowers of white, red or pink; Salvia ‘Indigo Spires” and ‘Mystic Spires Blue’ have large spikes of blue-purple flowers.
Peggi Canant, former Smith County Master Gardener
Texas A&M AgriLife Extension Service