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In nature, balance sustains life. Zhang et al. (pages 3216–3230) reveal how the small peptide CLE19 (in green color) and the brassinosteroid (BR, in orange color) hormone act as opposing forces to maintain balance in pollen wall formation in Arabidopsis. In this system, CLE19 signaling restrains BR output through the BSL–BIN2–BES1 cascade. When this equilibrium is disturbed, for example by too little BR or too much CLE19, the pollen wall becomes defective. Likewise, overly active BR signaling or insuffi cient CLE19 results in abnormal wall thickening and sterility. This study highlights the vital equilibrium between peptide and hormone signaling required for reproductive success in plants.