Use Jack's Professional Petunia FeED 20-3-19 as a fertilizer for petunias in pots, flower beds and hanging baskets. It's effective on many other plants as well, including bacopas (water hyssops), diascias (twinspur), basil and snapdragons. Just don't apply it to iron-sensitive flowers such as geraniums. Greenhouse Megastore guarantees the lowest price when you're stocking up on petunia fertilizer.
