Designer Joe Stead's tips for mastering the underwater look:
Add a showstopper. Every garden needs a striking plant, one that’s bigger or more colorful than the rest. Despite its petite size, the star-shaped Agave lophantha ‘Quadricolor’ (at top right) draws attention with its green stripes.
Mix lacy with bold. Keep your planting lively and interesting by clustering more textured, delicate succulents—like the trio of ruffle-edged echeveria hybrids pictured—around bolder, more muscular ones. ‘Sticks on Fire’ has the same effect behind a whopper agave.
Fill in with tiny mats. The little guys make the big ones stand out. Thanks to bands of starlike Crassula corymbulosa ‘Shark’s Tooth’, knobby blue Senecio serpens, and lime green Sedum rupestre ‘Angelina’, the three echeverias and the Aeonium ‘Sunburst’ (at far left) really pop.