Water-Loving Perennials for the Northwest


Yes, I realize that 2021 was the hottest on record with temperatures reaching 108°F, and we can expect the weather to continue to change radically. However, along with drought-tolerant plant choices we should also consider water-loving perennial plants.

As wet as the climate can be in the Pacific Northwest, we should all be embracing plants that love moisture. The year 2022 has been a bad one for tender or nonhardy things in my garden, largely due to the wet weather. The hybrid strawberry tree ‘Marina’ (Arbutus × ‘Marina’, Zones 7–9) that has been growing happily in my garden for four years died this year. It is a plant that really likes well-drained soil. Although in a good, raised location, the extreme cold temperatures mixed with the unrelenting rain did it in. Even in May, the ground was still soggy in places, with areas of the lawn unmowed because of standing water. Rainfall through mid-May was 21.35 inches (normal for the month is 17.37 inches). April 2022 was the third-coldest in history.

skunk cabbage

Despite its unfortunate name, skunk cabbage is an excellent choice for wet shade

Western skunk cabbage (Lysichiton americanus, Zones 3–9)—also called yellow skunk cabbage, American skunk cabbage, or swamp lantern—is found in swamps and wet woods, along streams, and in other wet areas of the Pacific Northwest, where it is one of the few native species in the arum family. Despite its foul floral scent (only off-putting in large stands), which attracts flies and beetles as pollinators, it is a handsome perennial with gigantic 3-foot-long, glossy leaves. This 3- to 5-foot-tall plant loves water and can even take standing water (riparian) in full to partial shade. It is hard to find in cultivation but well worth the effort.

 

Rotlaub rodgersia

‘Rotlaub’ rodgersia is a great ground cover for soggy sites

‘Rotlaub’ rodgersia (Rodgersia podophylla ‘Rotlaub’, Zones 6–9) is fast becoming one of my favorite shade plants. It grows well in moist shade beds and in wet soil, reaching to 24 inches tall and twice as wide. Lovely pinnate leaves with jagged edges bloom with a white flower in the late spring. There are several rodgersia varieties with red and green leaves. This one holds its red color the longest before changing to green later in the season. The contrast of the color amid all the bright greens in early spring is wonderful. If you plant it in more sun, it will stay red, but I have found that it will get a bit crispy on the edges with too much sun.

 

Umbrella plant

Umbrella plant is a slow-spreading native that isn’t bothered by deer or slugs

Another water-loving native to the Pacific Northwest is umbrella plant (Darmera peltata and cvs., Zones 5–9). Found along streams and wet areas, it puts some of the first pollinating flowers of the spring up before the leaves. This helps to make it visible to early pollinators. The satiny leaves push through the soil after bloom and extend up to 5 feet high on thin stems. This perennial is a slow spreader, though, reaching about 5 feet wide in 10 years. It’s not deer friendly, and slugs won’t eat it. Umbrella plant loves open light shade and constant moisture.

 

bulleys primrose

Primroses offer colorful options for damp locations

Bright color in the shade is sometimes hard to find. So when I found bulley’s primrose (Primula bulleyana, Zones 5–8), I was thrilled. This primrose has lovely orange and yellow flowers that emerge from attractive red buds in early summer. Bee’s primrose (Primula bulleyana subsp. beesiana, Zones 4–8) has dark vibrant pink, maroon, or purple flowers in late spring. Good shade and good moisture are the keys to success with this tough perennial as well. It can be a little aggressive, so be sure you plant it where it can spread around. Japanese primrose (Primula japonica and cvs., Zones 4–8) is also a great plant that can take a little more sun and less water. The tiered candelabra shape of the flowers is beautiful amid soft fronds of ferns in late spring. All three primroses mentioned grow to 18 to 24 inches tall and wide.

 

Last Dance leopard plant

‘Last Dance’ leopard plant shines with bright blooms in fall

Most of the plants mentioned have been spring flowering, but there is a great fall-flowering plant that keeps the moist shade garden going. ‘Last Dance’ leopard plant (Farfugium ‘Last Dance’, syn. Ligularia ‘Last Dance’, Zones 7–10) has bright, sunny, daisy-like flowers in the fall. It has dark green–toothed leaves that will eventually be upright (when the rain slows down). It grows 18 to 24 inches tall in filtered sun to shade. It too likes consistently moist soil and will eventually spread into a good size clump around 3 feet wide.

It is important to remember that moist soil does not mean stagnant, compacted soil. Anaerobic soil doesn’t have the air space in the soil to support plant growth. Many gardeners also create bog gardens to grow these great plants. This is easy to do with a big piece of pond liner filled with soil and close to an irrigation head. One edge of the liner should be a little lower to help it drain when overfilled with water (constant rain). Around the edge of a small pond is also a great place to grow these plants and to bring wildlife into your garden. When in Rome? Do as the Romans do. When the sky gives you rain, capture it and use it to grow a new type of garden.

—Susan Calhoun is the owner of Plantswoman Design in Bainbridge Island, Washington.

Photos: Susan Calhoun






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