Germinating Roridula dentata: Smoke Treatment and Soil Mix

A grower asks if smoke treatment benefits Roridula dentata germination and requests Jeff Dallas's experience with the genus.

Dallas has used smoke primer disks (link to Seedman.com) with good results. However, results vary: a December sowing of R. gorgonias had ~100% germination in 3 weeks; an identical January sowing had zero germination. Same seed batch. Either viability is short-lived, or photoperiod/temperature matters. He recommends sowing late November to early December under natural daylight.

R. dentata seeds are rare; Dallas notes their nursery has one plant and considers it the prettier species.

Follow-up: Grower obtained R. dentata seeds from another grower. Asks about germination medium. Dallas uses a coarse sandy mix (2 parts silica sand, 1 part perlite, 1 part peat)—same as for Drosophyllum and Byblis gigantea.

Smoke treatment mimics post-fire chemical cues that break dormancy in some Cape flora. Roridula (South African) responds to this, but timing appears critical.