When designing your rain garden, there are certain things to be kept in mind. It is advisable to use certain plants due to their advantages in helping the rain water get absorbed back into the ground as well as being able to adjust to the climate and environment. Before deciding on the plants you want to put in your rain garden, you should know that there are three zones within the rain garden. The plants differ from each zone and also vary depending upon the soil conditions, the amount of rain or sunshine the plants may receive and on how much water the garden can hold.
This article gives a comprehensive list on various shrubs, trees and plants that will be able to withstand wet conditions, fluctuating water levels with sun exposure. Native plants that are found in shaded environments in soil with high organic matter will not be suitable for use in a rain garden. The only advice we can give is to consider the sun/shade exposure and the depth of your rain garden when selecting the plants for your rain garden.
This is the first zone and it is this zone that will hold the most amount of water for the longest period of time as compared to the other zones. The plants that can be used for this zone are tolerant of flooded conditions and can tolerate standing water for lengths of time. You should design your grain garden in such a way that all rainwater is infiltrated within a 24 hour period.
You should plant the following shrubs like Elderberry, ButtonBush, St. Johnswort, Spice Bush, Swamp azalea, Swamp Rose, Wild Raisin and Winterberry. Some perennials and ferns like Blue Vervain, Golden Rod, Cinnamon Fern, Royal Fern, Sensitive Fern, New England Aster and Woolgrass can be used as well. Having trees like birch, bald cypress, Pond Pine, Sycamore and Swamp Oak could be a perfect fit for this zone. There are many more plant varieties that can be used in this zone apart from the ones mentioned here.
Mesic or Middle Zone
This area can also retain water but will drain out faster than the Wet Zone. It will be able to hold several inches of water during a heavy shower and also hold it after the rain event depending upon how the rain garden is constructed.
You can use shrubs like Inkberry, American beautyberry, Broad and Narrow-leaved meadowsweet, Sweet Pepperbush and Virginia sweetspire. Perennials like Bottlebrush grass, Culvers Root, Mistflower and Obedient Plant will work well in this zone, with the whole zone being rounded off with trees like Ninebark, Red Maple, and Pawpaw. Some of the plants listed in the Wet zone could also work in this Middle Zone.
This is the section that helps unite your rain garden and your non rain garden area. This is why it is known as the transition zone. Almost any variety that is commonly used in normal gardens can be used in this zone. This area will drain out the fastest during heavy rains and resembles most typical garden areas. One good tip would be to use native plants to really enhance the wildlife habitat and make your garden truly come alive.
Shrubs like Fragrant sumac, New Jersey Tea, Black Chokeberry, Yellow Root and Sweet pepperbush could work in this zone. Perennials like Blazing Star, Calico Aster, Butterfly Weed, Evening Primrose, Mistflower and Tickseed are also good favorites for this transition zone. You could plant trees like Buckeye, Carolina Silverbell and Staghorn Sumac to round up the zone and your rain garden will be ready for rain!