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Northwest native indoor plants

I’ve taken up planning plants for our office, and wondered if
you could give advice. I’m looking for Northwest native plants that would be
happy indoors, in an office environment. Available sunlight will vary by
spot but is generally low (but I can probably swing some plant lights); air
is standard low-humidity commercial-building air.

 

Most Northwest native plants I can think of are not ideal for growing
indoors. However, I asked my colleague who used to garden for the Seattle
Public Library, and she says that the library is growing native species
of ferns indoors. She notes that they are especially prone to pests
(whitefly) and diseases (scale), and must be watered every day.

Below is the list of plants being grown in the main (Central) library
branch:

  • Acorus
  • Blechnum spicant
  • Adiantum pedatum
  • Carex elata ‘Bowles Golden'(tall)
  • other fern (Rumohra adiantiformis?)

I hope this helps. If you wish to reconsider using natives in favor of
more traditional choices for indoor plants, there are many more choices
available. Below are a few links that may be use to you:

Low Light Houseplants from University of Vermont Extension

Growing Indoor Plants with Success from University of Georgia Cooperative Extension

Interior Plants: Selection and Care from University of Arizona Cooperative Extension

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Low maintenance Carex

I am designing a low maintenance landscape. I’m interested in using one of the Carex cultivars that have golden/variegated leaves (Carex dolichostachya ‘Kaga Nishiki’, Carex oshimensis ‘Evergold’, Carex morrowi ‘Ice Dance’, or Carex hachijoensis ‘Evergold’). I would like to use a species that does not need to be cut down each year. Can you advise if any of these would look good all year without cutting back in the winter?

According to The Plant Care Manual by Stefan Buczacki (Crown, 1993), most sedges (such as Carex) require little maintenance. Even those with tall flower stems don’t need staking, and only need their dead flower stems removed in spring, or if damaged by rain or wind. In general, foliage may be trimmed lightly in spring as needed.

Rick Darke’s Encyclopedia of Grasses for Livable Landscapes (Timber, 2007) says that Carex dolichostaya ‘Kaga Nishiki’ will form “a symmetrical fountainlike mound, eventually to 2 feet in diameter. Long-lived and durable, suited for groundcover sweeps. Fully evergreen into Zone 6. Prefers fertile organic soils and light shade or full sun with adequate moisture. Fairly drought-tolerant in shade once established.”

Darke says that Carex hashijoensis is similar to Carex oshimensis but not as cold-hardy. The variegated cultivar you mention, ‘Evergold,’ is actually a cultivar of C. oshimensis, not C. hachijoensis, but there is confusion in the nursery trade.

Carex morrowi ‘Ice Dance’ is described as “strongly rhizomatous but not so fast as to be a nuisance. A superb, self-repairing groundcover.” There are other cultivars, such as C. morrowi ‘Gilt’ (leaf margins cream-white), ‘Gold Band’ (leaf margins cream-yellow), and ‘Variegata’ (a catch-all name for otherwise unnamed variegated selections).

You may find this of interest: Darke’s section on cutting back grasses and sedges states that “most grasses require little maintenance other than being cut back once yearly, and even this is done more for neatness than for the needs of the grass. […] Many evergreen grasses and sedges do not need to be cut back yearly and may grow attractively for a number of years with just minor grooming. Old growth or discolored foliage is often easily removed by gently combing plants by hand.”

on adding sand and manure to clay soil

We would like to put in a new lawn around a home where there were mostly weeds. The soil is very a heavy silt because it is river bottom land. I have access to free sand; however, I’ve heard conflicting advice regarding adding sand to clay — some say yes, others no. I also have access to a large supply of free horse shavings/manure from a horse stable. Would those shavings be good to add to the soil to help lighten it and add nutrients? I don’t want to go to the expense of bringing in topsoil if I don’t have to. What are your suggestions?

Adding sand to clay soil is not recommended as a way of lightening the soil, as it “may create a concrete-like structure”, according to the booklet Ecologically Sound Lawn Care for the Pacific Northwest by David K.
McDonald. Linda Chalker-Scott addresses the reasons for this in depth in “The Myth of Soil Amendments Part II”.

Instead of adding sand, David McDonald recommends trying to till in compost. At least two inches of compost tilled into the upper six to eight inches of soil is recommended, but four inches tilled into the upper twelve inches is preferable . Try to avoid doing this when the soil is waterlogged, as it may damage the soil structure.

Composting the horse manure and shavings you have access to could be a feasible way to obtain the compost to till into the soil. The Guide to Composting Horse Manure by Jessica Paige of Whatcom County WSU Extension discusses how to compost and use horse manure. She recommends curing such compost at least a few weeks before application, and adds that one to three months is a good, typical composting time in summer or three to six months in winter.

Alternatively, according to David McDonald, if there are a few months of warm weather between autumn and seeding time, you could simply till the fall leaves and grass clippings into your soil. Depending on your planned schedule, this could be very easy. (You can find McDonald’s full booklet “Ecologically Sound Lawn Care for the
Pacific Northwest: Findings from the Scientific Literature and Recommendations from Turf Professionals” online as a very large PDF.)

Another option might be to consider some sort of groundcover if you discoverthat establishing a lawn is an excessively extensive project. Carex species or possibly Juncus phaeocephalus phaeocephalus are more naturally adapted to heavy soils in wet areas than lawn grasses and so may be less work in the end. Though they would not be appropriate for a heavy traffic area, they would be grasslike in structure. Sagina subulata might be more amenable to heavy traffic.

plants for restoring wetlands

I am an Ecologist with Adopt-A-Stream Foundation, a non-profit stream restoration organization. I am creating a planting plan for a golf course in Snohomish County. My constraints: Low-growing native shrubs with extensive root systems to help filter out the golf course irrigation water before it enters the stream. Willow would be an obvious choice, but it would grow too tall and out of control. I was looking at such species as Snowberry (Symphoricarpos), Nootka Rose (Rosa nutkana), Salmonberry (Rubus spectabilis), etc. It would have to be a FAC+ (streams and wetlands). Any thoughts?

FAC+ is a wetland indicator status term meaning “Facultative,” i.e., more likely to occur in wetlands but also found in non-wetlands.

I found a list in Restoring Wetlands in Washington Publ#93-17 and picked out the FAC-identified ones, eliminating all the tall trees and shrubs. Symphoricarpos (Snowberry) would be a good option, but Rosa nutkana (Nootka Rose) and Rubus spectabilis (Salmonberry) get too big for your purposes. A different rose I could recommend is Rosa gymnocarpa (Baldhip Rose). Many of the following recommendations are grasses of one sort or another. (See the USDA Wetland Indicator status definitions.)

Allium geyeri (non-native) FACU

Athyrium filix femina FAC

Carex aperta (non-native) FACW

Carex stipata FACW

Deschampsia caespitosa FACW

Juncus effusus and ensifolius FACW

Ledum glandulosum FACW

Sambucus racemosa var. melanocarpa FACU

Spirea douglasii FACW

You might also try the Snohomish County Conservation District website.

Carex species and difference between grasses and sedges

I was looking at the Great Plant Picks list of recommended grasses, and I wonder why they exclude Carex, which I find is such a useful plant in the garden.

 

Great Plant Picks does in fact list two different Carex species but they are not on the list of grasses because Carex is a type of sedge, and sedges are not grasses. An article entitled “Sedges Have Edges” from Hilton Pond Center for Piedmont Natural History has a detailed explanation of the differences among grasses, sedges, and rushes. All three are graminoids, but grasses are in the Family Poaceae, sedges are Cyperaceae, and rushes are Juncaceae. According to the article, “a simple ‘touch test’ is the giveaway for sedges, whose stems when rotated have a very noticeable triangular shape–hence a total of three ‘edges.’ ”

plants for banks of a fish pond

We need some advice and we are hoping you can help. We would like to replant the banks of our fish pond and want to know what kinds of plants would hold a steep slope and be compatible with the fish and each other. We have a large deer and elk population and we get substantial amounts of rain. We like grass-type shrubs and we need a ground cover that will not take over and is evergreen.

 

From the research I have done, it seems that a pond with a sloping side is a very good idea, but if erosion is a serious issue, you may want to think about both plants and physical controls such as coconut fiber matting to stabilize the banks. The Brooklyn Botanic Garden’s guide (1997), The Natural Water Garden, has a description of using coconut fiber tubes (also called biologs) laid horizontally along a bank, which can also be used as a secure planting medium for seedlings.

As far as deer-resistant plants which may work for your site, iris and spiraea appear to be unappealing to deer, so you might want to try some of the irises which prefer moist situations, such as Iris laevigata, and Iris versicolor (blue flag), as well as Spiraea douglasii (hardhack).

Other plants which may help with preventing erosion are Lysichiton americanum (skunk cabbage), Athyrium filix-femina (lady fern), Carex obnupta (sedge), and Cornus stolonifera (red osier dogwood) or C. alba (red twig dogwood).

Some grassy or reedy plants which do well as marginal (water’s edge) plants include Acorus calamus ‘Variegatus’ (variegated sweet flag), Pontederia cordata (pickerelweed), Sagittaria latifolia (American arrowhead), and Typha latifolia (cattail). All of these are deciduous.

For evergreen plants, you could try Scrophularia auriculata ‘Variegata’ (water figwort), an evergreen perennial with cream-edged foliage. The flowers should be deadheaded to prevent self-seeding. Thalia dealbata (hardy canna) is evergreen, with long-stalked blue-green leaves and violet flower spikes.

on pruning sedges

The Carex buchananii in my parking strip garden is now large enough that it’s reaching out over the sidewalk and getting underfoot. Can I safely cut it back? Can it be cut to the ground in spring and allowed to start over?

 

Sedges like yours should not be cut back too far. The magazine Horticulture says you can “gather up the leaves in one hand and, using a pair of scissors, cut off the top third, including the long flowering stems. This will leave the plant arching out gracefully, but not trailing along the ground. It may be necessary to do this twice a year: at the beginning and end of the summer.”

Val Easton, writing in the Seattle Times (October 8, 2008) says “sedges resent being cut back too hard, so if the foliage lasts through the year untattered, just leave it alone. If the older foliage looks messy, or the tips have been burned by winter cold, trim the sedge back modestly, by no more than a third at most, in March or April.” Another thing you could do is to dig up and divide your Carex in March, and move it away from the edge of the planting bed.

Garden Tip #85

If you think a shady garden is a liability there is a good book that will change your mind. Gardening in the Shade (Horticulture Books, 2004) was compiled from articles that originally appeared in Horticulture Magazine. The book is divided into four sections: techniques, general design, plant for shade and step by step projects. Some of the plants suggested are Epimedium, sedge, Cyclamen and Japanese Spicebush (Lindera obtusiloba). Any one with cedar trees in their garden will want to read the essay by a local Northwest writer on coping with dry shade.
Other resources for shade gardening include the classic book, The Complete Shade Gardener by George Schenk (Timber Press, 1984) and the web page created by University of Missouri Extension.