With so many interesting miniature varieties available, it might be fun to try a few dahlias in the greenhouse.
Seeds sown in February germinate rapidly in sphagnum moss. When seedlings are large enough to handle, transplant to 3-inch pots in soil rich in humus. Plants grow rapidly and, if not crowded, do not require pinching to induce branching. Shift to larger pots as necessary. Buds set in a few weeks, and if given plenty of sun will start flowering in early summer.
You can also propagate dahlias by dividing tubers in February, placing the divisions in moist sand with bottom heat until leaves appear and plants are large enough to handle. Transfer to 3-inch pots and treat same as seedlings.
'Early Bird', extra double dwarf; Tall Festival'; Coltness Hybrids.