Getting double blooms with lots of petals I think direct seeding zinnia seeds can help (right into the soil outside), but I oftentimes start them in trays because I find that easier. Container Gardens in the Shade Eising Garden Centre Modern White Outdoor Planters, Plant Pots, Box. White Tall, Large Fiberglass and White Metal Pots for Outside Plants, Trees. Entryway NMN Designs Plant Seeds Of Kindness Inspirational Quote Art Black Licorice Herb (2 Pack) Bonnie Plants Resin Planter with 3 Dividers and 3 Plastic Pots Plow & Hearth