Rent Shop Volunteer Join

Q. Who is Mr. Smarty Plants?

A: There are those who suspect Wildflower Center volunteers are the culpable and capable culprits. Yet, others think staff members play some, albeit small, role. You can torture us with your plant questions, but we will never reveal the Green Guru's secret identity.

Help us grow by giving to the Plant Database Fund or by becoming a member

Did you know you can access the Native Plant Information Network with your web-enabled smartphone?

Share

Ask Mr. Smarty Plants

Ask Mr. Smarty Plants is a free service provided by the staff and volunteers at the Lady Bird Johnson Wildflower Center.

Search Smarty Plants
See a list of all Smarty Plants questions

Please forgive us, but Mr. Smarty Plants has been overwhelmed by a flood of mail and must take a break for awhile to catch up. We hope to be accepting new questions again soon. Thank you!

Need help with plant identification, visit the plant identification page.

 
rate this answer
Not Yet Rated

Wednesday - July 30, 2014

From: Camano Island and Orcas Island, WA
Region: Northwest
Topic: Rain Gardens, Groundcovers, Grasses or Grass-like
Title: Groundcover for a wet hillside in the San Juan Islands
Answered by: Larry Larson

QUESTION:

I live on Orcas Island in WA state. We have a place on the water and want to plant something that is no taller than 2-3 feet, lower if possible, on a hillside. The hillside gets lots of sun, yet also has a lot of water in the ground since the mountain near us drains down toward the sea. We'd like to cover the hillside, about 3-5 feet wide and 20 feet long with a type of ground cover or plant that will fill the area. I looked at butterfly weed, but that doesn't seem to be a WA state type of plant. Any other ideas for wet ground, full sun, ground type cover plants?

ANSWER:

  Mr Smarty Plants doesn’t have a lot of material on the San Juan Islands, so I’m going to look at similar areas and check if their recommendations work at Orcas Island.  Here are a few Mr Smarty Plants question/answer pairs that have useful discussion and suggestions.  I have extracted just a few of their suggested groundcovers that are adapted to full sun and wet or moist soil and are indicated to grow as a native in the San Juan Islands.

  Farthest afield is “Plants to replace Polygonum cuspidatum ( Japanese knotweed) which was actually written from Wisconsin.  This discussion suggested both Arctostaphylos uva-ursi (Kinnikinnick) and Cornus canadensis (Bunchberry dogwood), which are also native to NW Washington and the Islands.

  “Groundcover for Oregon gravel path” suggests Fragaria chiloensis (Beach strawberry) and Fragaria virginiana (Virginia strawberry) and even closer to home  “Low maintenance, shade tolerant groundcover for Pacific Northwest”  recommended  Linnaea borealis (Twinflower) and Mahonia nervosa (Cascade barberry).   All of these are groundcover or low shrubs, are adapted to full sun and wet to moist soil.  In addition, they are indicated to be native to the San Juan Islands according to the USDA.

  Another method we use is a direct search.  The Wildflower Center maintains a set of "Recommended Species” for many states and ecoregions.  This is the list for Washington State. On the left hand side of the web-page, one can search the collection for several attributes.  When I did that for “grass & grass-like” aspect, full sun and wet or moist soil, the search revealed three more candidates.  They are  Carex stipata (Awlfruit sedge), Distichlis spicata (Saltgrass) and Trisetum spicatum (Narrow false oat).

  Those are my suggestions for your groundcover.  I also found these locally interesting question/answer pairs.    “Grass for Seattle Arboretum”, is of course close, but has recommendations for different applications and climate.  Resources for Camano Island is directly applicable, but “just” contains a number of excellent reference books and information for that area.

 

From the Image Gallery


Kinnikinnick
Arctostaphylos uva-ursi

Bunchberry dogwood
Cornus canadensis

Beach strawberry
Fragaria chiloensis

Virginia strawberry
Fragaria virginiana

Twinflower
Linnaea borealis

Awlfruit sedge
Carex stipata

More Rain Gardens Questions

Plants for a wet area in Ohio
March 30, 2010 - I have a lot of water in my front yard are there any kind of plants that I can plant to drink up some of the water? I live in North East Ohio
view the full question and answer

Plants for freestanding water in Oklahoma
July 28, 2013 - I have an overflowing gutter and the ground below becomes a muddy hole. I'd like to put a basin or pot in/or above the ground with a rain chain. Are there any plants--shrubs or otherwise that flouris...
view the full question and answer

Smarty Plants on water-absorbing plants
July 19, 2005 - I am looking for water-absorbing plants for L.A. zone. I am hoping this type of vegetation would ease the water retention problem at the planter right next to my basement. Is this a feasible solutio...
view the full question and answer

Rain Garden plant for N. Mississippi
March 03, 2010 - Rain Garden Plants for North Mississippi/Mid-South Region. I wish the search parameters included plants which tolerate seasonal flooding and droughts, so that each state might search for its own r...
view the full question and answer

Plants for floodplain in Fairfield, New Jersey
March 21, 2010 - I have an easy question for you... I hope... We just moved into the floodplains of NJ in Fairfield and are interested in some plants. We would like to know what plants are best suited to grow in flood...
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.