Joanna, those dahlias are beautiful. Now you mentioned you store the tubers in a heated garage during the winter. We can't leave ours in the ground during the winters either. Learned the hard way the second year we grew them..they will freeze and rot. What kind of container do you store the dahlia tubers in? Somebody suggested using we use shredded black and white newspaper, or vermitculite, or pine straw or even saw dust. Then they store them inside a sytrofoam cooler with the lid cracked open a little for air circulation or one of those kitty litter tubs.
Since purple/lilac is one of my favorite colors, I'll say it's my favorite out of those that you posted above.
Winter-Sowing, Direct Sowing, Indoor Seed Starting, Hobby Greenhouses, Cold Frames, Germination Seedling & Plant Care for Annuals, Biennials, Perennials, Herbs, Vegetables, Tomatoes and Peppers. A gardening cubit that covers it all!
Stratification: Chilling seeds to promote germination. Damp paper towel in a baggy & put in fridge Scarification: Scratching or notching seed coat. Soaking with Hydrogen Peroxide & Water works too Damping Off: a fungal disease that causes seedlings to die soon after germination
Chamomile Tea prevents damp off. Steep 20 min, cool to room temp & water your trays