Richters InfoSheet D9005  

Herbs for Wet Places

By Inge Poot

To define what we mean by herbs: plants are considered to be culinary herbs if they can be used to flavour food (spices), medicinal herbs if they cure or control ailments (of humans, animals or plants), fragrant herbs if they are used to perfume air, or dye plants if they are used to dye fabrics. Many herbs fit into more than one category.

In talking about herbs for wet places, we have to divide the list of plants into groups that tolerate or demand different degrees of wetness.

The largest number of herbs demand good drainage, but don’t tolerate drought equally well. Those that need to be moist at all times still form a large group and I will only mention those that look just too wonderful at the side of ponds to be omitted. They could be grown at the edge of a natural pond 6 to 12" above the level of the water or could be placed on top of a 6 to 12" mound of sand or peatmoss -- depending on their pH and humus requirements -- placed into an enclosure built up from the shelf of an artificial pond. They would have water creep up by capillary action, but still have plenty of air at the roots for a depth of 6 to 12" due to the porous structure of the planting medium.

The water level is 2 to 4" below the crown of the plant and with the planting medium pH acid we have a bog or with it alkaline we have a swamp. Periodic complete submersion of the plant does no harm.

The plants can or must be always submerged.

The plants will need either full sun (s), part shade (psh) or full shade (sh).

The following is an alphabetical listing of herbs for variously wet places, giving botanical name, (common Name(s)), wetness required, sun required, hardiness:

Acorus calamus americanus
Calamus, Sweet Flag
wet to submerged, (s-psh), Z3-9
Plant has sword shaped leaves much like an iris or a cat-tail. The inconspicuous flower spike emerges about half-way up the leaf, is about 10 cm long and like a slim corn-cob in structure. The European strain of this plant (the variegated ones are European!) contain the carcinogen cis-isoasarone and cannot be used medicinally. The roots can be dried and powdered and used as a fixative for potpourri. In India, used as a vermifuge and insecticide especially for fleas. Medicinally use is for flatulent colic, gastritis and dyspepsia.

Althaea officinalis
moist, (s), Z3-9
Sweet mucilagenous herb, used to soothe irritation and control bacterial infection of digestive tract and upper respiratory tract and skin. Tall with small, pink hibiscus flowers and can be harvested with impunity. The much more showy Hibiscus palustris (Swamp Rose-mallow), (moist to wet) has very similar properties. The straight species has huge pink flowers and the forma peckii, or by some authorities the species H. moscheutos, has white flowers with a red eye. It is available as the stunning hybrid ‘Southern Belle’ (Stokes #965). Grow it in neutral mud and be patient in spring as it does not emerge until early June.

Anemarrhena asphodelioides
Zhi Mu
moist, (s), Z2-7
Looks like a tall grass with fragrant yellow-white or light purple flowers that open in the evening in the late summer or fall. The rhizomes have been used in China for 2000 years for their antidiabetic and antibacterial properties. Useful for pneumonia, bronchitis, high fever, irritability and insomnia.

Chervil (Anthriscus cerefolium)

Anthriscus cerefolium
moist, (psh), Annual
Seed lasts only one year. Short leafy herb with tiny white flowers. Fresh leaves used on potato, egg and fish dishes. Medicinally it is used internally to combat fluid retention and jaundice and externally for inflamed eyes and haemorrhoids. It is said to repel ants and aphids from lettuce and repel slugs.

Arisaema tryphyllum
moist to wet, (psh), Z4
First nations people used the roasted or pounded and dried roots as food and to treat asthma, whooping cough, bronchitis and externally for rheumatism, boils and snakebite. Raw plant very toxic. Do not use without medical supervision.

Cypripedium parviflorum var. parviflorum
Small yellow ladyslipper
wet, (psh), Z4
Lovely plant with hairy leaves and stems carrying one or two graceful flowers with dark brown sepals and petals and a bright yellow pouch -with or without red markings. Plant in artificial or natural swamps and mulch in winter - snowless winters severly damage or kill the plants. The drier growing C. p. var. pubescens is available from Fraser Thimble Farm. North American First Nations people used the plant as a tranquilizer. Since this plant is heavily protected and endangered due to habitat loss, for this use, this plant has been replaced with Lavandula angustifolium and Scutellaria lateriflora.

Filipendula ulmaria
moist to wet, (s), Z3-9
Attractive European wildflower with sweet almond-scented, yellow-white or reddish flower heads. Contains salicyclic acid, chemically similat to ASA. Useful for flu, gout, rheumatism, arthritis, fever, etc. Once added to herbal beers and wine.

Geum rivale

Water Avens
wet, (psh-sh), Z4

Modest brown and red-brown bells with yellow stamens produced from somewhat hairy plants with pinnate leaves. Weaker, but similar action to the (ugly!) better known Geum urbanum -- the latter being drier growing too. It is astringent, antiseptic and a tonic for the digestive system.

Hibiscus palustris -- see Althaea officinalis

Hierochloe odorata
Sweetgrass, Holy Grass
moist, (s), Z3-9
A grass which when dried develops a vanilla scent. Used as a perfume, a scent fixative and to make fragrant baskets. Plays a role in peace and healing rituals of First Nations people.

Iris versicolor
Blue Flag, Blue Water Iris
wet, acid soil to shallow water, (s-psh), Z3
Jaunty blue flowers in spring from 30 cm plants. It is an acrid, slightly aromatic, alterative herb that stimulates the liver and gall bladder, reduces inflammation, increases perspiration and salivation and is a diuretic and laxative. Not for pregnant women.

Iris pseudacorus
Yellow Flag, Yellow Water Iris
wet to shallow water, (s-psh), Z4
90-150 cm tall plants with bright yellow flowers pencilled in black. The rhizomes contain lots of tannins and are used primarely as an astringent, but also as a diuretic, laxative, vermifuge and to induce retching in case of poisoning.

Kalmia angustifolia
Sheep Laurel
acid soil, moist to wet, (s-psh), Z3
Smaller than Mountain Laurel (Kalmia latifolia), but also hardier. Flower clusters not terminal as in Mountain Laurel, but has same uses and is just as toxic to livestock, especially sheep-hence the name! Deer can eat it, it won’t taint their meat, but the intestines of such a deer must not be eaten by dogs, as it may kill them. Nectar used by bees to make honey, results in toxic honey! To be used by a qualified practitioner only. Internally for syphilis, inflammatory fevers, diarrhoea, bowel hemorrhage, neuralgia, paralytic conditions, tinnitus and angina. Externally for herpes, scalp conditions and skin irritations.

Gayfeather (Liatris spicata)

Liatris spicata
Blazing Star, Gayfeather
moist to wet, (s), Z4-9
Produces strong spikes of rosy-purple flowers. Tuberous roots make soothing tea valuable in kidney diseases or as a gargle for sore throat.

Lobelia cardinalis
Cardinal flower, Red Lobelia
wet, (psh), Z5-9
Lovely brilliant red flowers on a tall inflorescence. Hummingbirds love it. If allowed to go to seed tends to be monocarpic. Needs to make new offsets at the plant’s base in fall to come up again next year. Said to be anthelminthic (fights intestinal worms), nervine and antispasmodic.

Lobelia siphilitica
Great Lobelia
moist to wet, (s-psh), Z4-9
Lovely blue to white flowers on a robust inflorescence. The hybrid between L. cardinalis and this species can be very desirable. It produces purplish-red flowers, is hardier and less prone to be monocarpic. Combined with mayapple (Podophyllum peltatum) the plant used to be used to fight veneral disease.

Lythrum salicaria
Purple Loosestrife
moist to wet to shallow water in alkaline to neutral soil, Z4-9
Dig out from a roadside ditch near to you! Not commercially available as a result of heavy lobbying by misguided environmentalists. The plant does not replace native species, it is just very good at infilling. Since its natural enemies have been released, it will soon be just as rare a plant here as it is in Europe. A beautiful road-side wild flower with tall spikes of small, magenta to rose flowers. It is a highly astringent, anti-bacterial, diuretic and soothing herb and has many medicinal uses.

Melissa officinalis
Lemon Balm
moist soil, (s-psh), Z5-9
Crinkly, hairy-leaved herb that quickly forms a mat. Restrain in zone 5 or warmer, mulch heavily in zone 4. Delightful tea is made from the various citrus-scented varieties. The tea stimulates the heart and calms the nerves and fights herpes.Fresh chopped leaves are nice in salads, soups and stews.

Mentha aquatica
Water Mint
moist to wet, (s-sh), Z6-11
Round leaved plant with strong menthol flavour. Both peppermint and orange mint are derived from this. Of the hybrids or selections the hardiest ones, hardy to Zone 4 are: Chocolate mint (chocolate-peppermint scent), English mint (a spearmint), lime mint, orange mint (heavenly!), variegated peppermint, spearmint, curled spearmint, menthol mint- all available from Richters. Plant mints in containers or they will take over your garden. Wonderful tea plants. Peppermint is good for indigestion. Spearmints are also great chopped over carrots, peas, potatoes and mint sauce for lamb.

Menyanthes trifoliata
Bogbean, Buckbean
wet to shallow water, (s-psh), acid soil, Z4
Creeping plant with three-leaflet leaves and upright inflorescences of pale pink fringed flowers (Gentian Family) Leaves used internally as digestive stimulant and for lymphatic drainage. This bitter herb is used to fight anorexia, indigestion, arthritis, rheumatism,chronic infections and debility.

Monarda didyma
Red bergamot, Beebalm
moist to wet soil, (s), Z4-10
Has been crossed with the dry-land M. fistulosa to get various other colours such as pink and purple. Shaggy heads of red to pink to purple flowers on long leafy stems. Attract hummingbirds. Most cultivars have a good lemon flavour and are great for tea.

Myrica gale
Bog Myrtle
sandy, acid soil, well-drained to wet, (s-psh), Z4
Myrica pensylvanica
as above, but Z5-9
Shrub with leathery leaves and wax-covered fruits. Leaves used as a substitute for hops, for tea and to flavour soups and stews.

Nasturtium officinale
moist, slightly alkaline soil to shallow flowing water, (s), Z5-9
Don’t collect from the wild, because it likes the sort of nutrient rich waters that are bound to be contaminated by such things as the liver fluke! Considered a spring tonic, popular as a salad ingredient and as a garnish for creme soups etc. Medicinal uses are internally for oedema, catarrh, bronchitis, wet coughs, skin eruptions, rheumatism, anaemia, debility of chronic disease and gall bladder complaints.

Nelumba nucifera
rich, wet soil to still, 30-50cm deep water, (s), Z5
Parasol shaped leaves emerge from the water and are followed in late summer by white to pink single or double flowers with a distinctive flat-topped bumpy pistil. Leaves are used in cooking to wrap rice mixtures for steaming. Medicinally various parts are used. The plant is astringent and cooling herb that controls bleeding, lowers blood pressure and fever, sedates heart energy and is a kidney and spleen tonic.

Nymphea odorata
White fragrant water lily),
still, 50 -90 cm deep water, (s), Z4
Lovely native North American water plant producing floating leaves and fragrant, white blooms -- lasting each 3 days- in summer. Astringent, soothing, antiseptic rootstocks. -But much too beautiful to harvest!

Garden Sorrel (Rumex acetosa)

Rumex acetosa and Rumex scutatus
Garden Sorrel and French Sorrel
moist, (s-psh), Z4-8
Tender leafy plants with a sour taste. Leaves are lovely in salads and sauces. Acidic, astringent and cooling herbs that are slightly diuretic.

Salix alba
White Willow
moist to wet, heavy soil, (s-psh), Z2
Eventually a 75 foot tree. Leaves and bark contain an aspirin-like ingredient that is astringent, cooling, pain relieving, fever and inflammation reducing.

Symplocarpus foetidus
Eastern Skunk cabbage
deep rich, moist to wet lime free soil, (s-sh), Z4
Mottled brown, very stinky flowers precede the cabbage-like leaves in spring. Roots are a warming, pungent anti-spasmodic and sedative herb.

Thymus species
moist, (s), Z as noted for the variety listed
The low creeping thymes make lovely carpets between paving stones so often used as edging for ponds. Almost all are good for culinary use, but the upright varieties are easier to harvest. The creeping varieties offered by Richters that are hardy in zone 4 are: Purple Carpet Thyme (Thymus praecox arctius ‘Purple Carpet’), Z2-9, under 5cm tall with lemon scent #6465-700 Orange Spice Thyme (Thymus ‘TM95’) Z4-9, orange flavoured and ground hugging! #6465-800 Creeping Thyme(Thymus praecox) Z4-8, very low thyme with good culinary thyme flavour. #6463 Wild thyme (Thymus pulegioides formerly called Thymus serpyllum), Z4-8. Slightly higher than creeping thyme, but is available as seed and has good taste. #6470 The upright culinary varieties offered by Richters hardy in zone 4 are: English thyme, French thyme, and Silver Thyme -- all varieties of the species Thymus vulgaris are hardy in zone 4-8, #’s 6450-6452, 6455, 6456. They make lovely mounds of fragrant woody stems with tiny leaves and conical bunches of purple flowers in summer.

Typha latifolia, Typha angustifolia
Cat-Tail, Bullrushes
wet soil to shallow water, (s), Z3
The common name bullrush is also applied to Scirpus species and hence leads to confusion. Somewhat invasive plants with tall handsome foliage and pipe-cleaner like inflorescences coming from sturdy rhizomes. The pollen is a sweet, acrid herb that is diuretic, controls bleeding, improves circulation, healing and stimulates the uterus. Dried pollen is anti-coagulant and roasted with charcoal it becomes haemostatic. The peeled roots are cooked and eaten or dried and ground into a delicious flour substitute. (Snow geese dig up and gobble the roots too!)

Wasabi (Wasabia japonica)

Wasabia japonica
Japanese horseradish
moist to wet soil, to running water, (sh), Z8-10 (over-winter indoors or mulch heavily)
Roots are harvested spring and fall, 15 to 24 months after seeding. Served grated with sashimi (raw fish) or dried, powdered and worked into a paste that is used to flavour meat and fish dishes. Medicinally it is used internally as an antidote to fish poisoning.

Zizania aquatica
Wild Rice
shallow water, (s), Annual
Not really a herb, but a food. Fresh seeds have to be sprinkled on top of the water in the fall. Since birds and fish love the rice just as much as we do, the sown area must be fenced off with fine netting, from below and above.


Bown, Deni. Encyclopedia of Herbs & their Uses. Wonderful book on names, culture (little on Zone info) and harvest, but generalities only for precise use information. The first edition is a bit cumbersome to use because each herb occurs in two sections. The second edition fixes this. Richters’ # B2730.

Richters Catalogue. Great reference, zones given and general use, but need to go to their website ( for precise cultural and some use info. See "Q&A" and "Richters InfoCentre" sections, the latter contains a good "Richters Herb Growing Infobase," and "The Grower Zone". Also they have a huge everchanging books for sale section, that will get your mouth watering!

Poletti, Aldo. Heilkraeftige Pflanzen in Farbe. Great book with colour photos, precise cultural and use information, but you have to know German! Formerly sold by Richters, but alas, no longer. Try

Moore Water Gardens Catalogue. Good for zone information of the plants they sell. No index makes it hard to find things.

Peterson, Roger Tory and McKenny, Margaret. A Field Guide to Wildflowers, of NE & N-central N-America. Great for pictures and Botanical as well as common names and how to distinguish the species occurring in this area.

Fraser’s Thimble Farms Catalogue. Great for botanical as well as common names and for zone, cultural tips and height information. An index would make finding plants easier, since they are grouped as to type e.g. ferns, orchids, with perennials -- for any not grouped elsewhere.

Lust, John. The Herb Book. An out-of-print little booklet that is the best for precise use information. Try

Grieve, Margaret. A Modern Herbal. An out-of-print treasure that contains good precise use information. Try


We welcome your feedback on your experiences. The information you provide will help us refine our recommendations to other herb enthusiasts. Please email your comments to Infosheet Feedback.


Reprinted from Ontario Water Garden Society Newsletter, April and May, 2004. Inge Poot is Richters Q&A horticulture expert.

Richters Herbs
©2004 Inge Poot


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