Water petunias and lobelias when the soil feels dry; both plants are drought-tolerant but you shouldn’t let the soil gettoo dry because lobelias can dry quicker than petunias do.
To grow themboth in a container, opt for a 12-inch diameter pot, allowing ample space for the petunias to spread, with the lobelias trailing down the sides.
These plants are a match made in heaven because they both require very little maintenance. You can grow both lobelias and petunias in hanging baskets or hard-to-reach flower beds.
To keep them healthy and encourage flower production, you should give your flowering plants some fertilizer. Use a slow-release kind of fertilizer once or twice during the season or a liquid fertilizer when watering.