Proven Winners Supertunias are the best petunias available and they come in an array of breathtaking colors! These beauties will be exploding with blooms all season long and love to spill over the edge of containers, window boxes and hanging baskets too! For amazing containers, use our Organic Potting Mix, Bio Tone Starter and Schultz Slow Release Fertilizer at time of planting. To keep your plants looking great all season, water your plants as soon as soil starts to dry and feed once every week with Jacks Petunia Feed.