Rain Garden
Plant Calculator
Please enter the following information about your garden.
Plant Calculator
How many plants will my rain garden require?
To calculate the number of herbaceous perennials required for an 18" spacing, you can divide your rain garden's area in square feet by 2.25; or just fill in the blank in the handy plant calculator and let it do the rest!
Shrubs and trees will be used at greater spacing in large rain gardens, usually five to 20' apart.
While it may be tempting to try, establishing plants from seeds in your new garden is very difficult. First, a good rain will likely wash seeds away. Second, your rain garden needs deep plant roots to work. It may take several seasons for native plants to develop to maturity from seed. By using plugs or larger plants, you are "buying time" and will be that much closer to helping reduce runoff.