How to plant dahlia cuttings (and yes—they’ll make tubers) If you’re trying to stretch your stock or only have one tuber of a variety, taking cuttings is a great way to multiply it over the winter. Cuttings will form tubers their first year—but they’re often small and tightly clumped. This planting method gives them the best shot at making usable, storable tubers by the end of the season. 🌞 🌱Cuttings should be planted at the same time as your tubers—once the soil is warm enough for tomatoes. H