Plants and Seeds Whose Sales are Prohibited in Washington State

Why are sales prohibited?

Every year noxious weeds and other invasive exotic plants cost Washington millions of dollars in lost production, public and private control costs, and environmental degradation. These exotic introductions to Washington have displaced native plant communities, damaged range and recreational lands, and degraded fragile wetlands. Escaped ornamentals are one significant source of infestation. It is often difficult to predict which ornamentals will be invasive and aggressive. Scotch broom, purple loosestrife, and kochia are prime examples of plants which have escaped cultivation and caused enormous economic and environmental damage. The quarantines identify plants known to be invasive and a detriment to the state's natural resources. These regulations will serve to prevent the continued introduction of these problem plants into Washington. (WAC 16-752-400 through 420; WAC 16-752-500 through 525 and WAC 16-752-600 through 660).

What is the penalty for violations?

Persons violating the quarantine restrictions may be subject to civil penalty of up to $5,000 per violation. If you see a prohibited weed for sale in Washington, please contact the Washington State Department of Agriculture's Nursery Inspection Supervisor - Tom Dabalos at (253) 872-6480.

Which plants and seeds are prohibited?

1. Terrestrial Noxious Weed Seed and Plant Quarantine WAC 16-752-610
   For the following noxious weeds, it is prohibited to transport, buy, sell, or offer for sale or distribute seed packets, flower seed blends, or "wildflower mixes" of these regulated species:
   • blueweed, also known as viper’s bugloss and blue-devil (Echium vulgare)
   • buffalobur (Solanum rostratum)
   • clary sage (Salvia sclarea)
   • common bugloss (Anchusa officinalis)
   • common crupina (Crupina vulgaris)
   • Dalmatian toadflax (Linaria dalmatica ssp.dalmatica)
   • dwarf snapdragon (Chaenorrhinum minus)
   • dyers woad (Isatis tinctoria)
   • eggleaf spurge (Euphorbia oblongata)
   • garlic mustard (Alliaria petiolata)
   • giant hogweed (Heracleum mantegazzianum)
   • goatsrue (Galega officinalis)
   • gorse, furze (Ulex europaeus)
   • hawkweed, mouseear (Hieracium pilosella)
   • hawkweed, orange also known as red daisy, flameweed, devil’s weed (Hieracium aurantiacum)
   • hawkweed, yellow also known as devil's paintbrush, yellow paintbrush devil’s paintbrush, and yellow paintbrush (Hieracium caespitosum)
   • hawkweed, yellow devil (Hieracium floribundum)
   • hedgeparsley (Torilis arvensis)
   • indigobush, lead plant (Amorpha fruticosa)
   • johnsongrass (Sorghum halepense)
   • knapweed, bighead also known as lemon fluff and globe centaury (Centaurea macrocephala)
   • knapweed, black (Centaurea nigra)
   • knapweeed, brown also known as rayed knapweed, hard-heads, brown centaury (Centaurea jacea)
   • knapweed, diffuse (Centaurea diffusa)
   • knapweed, meadow (Centaurea jacea x nigra)
   • knapweed, spotted (Centaurea biebersteinii)
   • knapweed, Vochin (Centaurea nigrescens)
   • kochia, also known as burning bush, summer-cyprus, fireball and Mexican fireweed (Kochia scoparia)
   • lawnweed (Soliva sessilis)
   • leafy spurge (Euphorbia esula)
   • meadow clary (Salvia pratensis)
   • Mediterranean sage (Salvia aethiopis)
   • oxeye daisy, also known as white daisy and field daisy (Leucanthemum vulgare)
   • perennial pepperweed (Lepidium latifolium)
   • policeman’s helmet, also known as Himalayan balsam and jewelweed (Impatiens glandulifera)
   • purple starthistle (Centaurea calcitrapa)
   • saltcedar (Tamarix ramosissima)
   • Scotch broom (Cytisus scoparius)
   • silverleaf nightshade (Solanum elaeagnifolium)
   • Spanish broom (Spartium junceum)
   • spurge flax (Thymelaea passerina)
   • Syrian bean-caper (Zygophyllum fabago)
   • tansy ragwort (Senecio jacobaea)
   • Texas blueweed (Helianthus ciliaris)
   • thistle, Italian (Carduus pycnocephalus)
   • thistle, milk (Silybum marianum)
   • thistle, musk also known as nodding thistle (Carduus nutans)
   • thistle, plumeless (Carduus acanthoides)
   • thistle, Scotch (Onopordum acanthium)
   • thistle, slenderflower (Carduus tenuiflorus)
   • unicorn plant (Proboscidea louisianica)
   • velvetleaf (Abutilon theophrasti)
   • Venice mallow also known as flower-of-an-hour (Hibiscus trionum)
   • wild carrot, also known as Queen Anne's lace (Daucus carota)
   • wild chervil (Anthriscus sylvestris)
   • wild four o’clock, also known as umbrella wort (Mirabilis nyctaginea)
2. Wetland and Aquatic Weeds WAC 16-752-500 through 525
   It is prohibited to transport, buy, sell, offer for sale, or to distribute plants or plant parts of these regulated plants, into or within the state of Washington. It is further prohibited to intentionally transplant wild plants and/or plant parts of these species within the state of Washington.
   • African elodea (Lagarosiphon major)
   • Brazilian elodea (Egeria densa)
   • cordgrass, common (Spartina anglica)
   • cordgrass, dense-flowering (Spartina densiflora)
   • cordgrass, salt meadow (Spartina patens)
   • cordgrass, smooth (Spartina alterniflora)
   • Eurasian watermilfoil (Myriophyllum spicatum)
   • European frog-bit (Hydrocharis morsus-rana)
   • fanwort (Cabomba caroliniana)
   • flowering rush (Butomus umbelatus)
   • garden loosestrife (Lysimachia vulgaris)
   • grass-leaved arrowhead (Sagittaria graminea)
   • hairy willow herb (Epilobium hirsutum)
   • hydrilla (Hydrilla verticillata)
   • marsh dew flower, also known as Asian spiderwort (Murdannia keisak)
   • mud mat (Glossostigma diandrum)
   • parrotfeather (Myriophyllum aquaticum)
   • slender-leaved naiad, also known as brittle naiad (Najas minor)
   • swollen bladderwort (Utricularia inflata)
   • water chestnut, bull nut (Trapa natans)
   • water primrose (Ludwigia hexapetala)
   • yellow floating heart (Nyphoides peltata)
3. Lythrum Quarantine WAC 16-752-400 through 415
   • purple loosestrife (Lythrum salicaria)
   • wand loosestrife (Lythrum virgatum)

It is prohibited to transport, buy, sell, offer for sale or to distribute plants, plant parts or seeds of Lythrum salicaria or L. virgatum into or within the state of Washington. It is also prohibited to transplant wild plants and/or plant parts of these species in the state of Washington.

The Lythrum quarantine applies to all Lythrum species including any hybrid cross and all named cultivars, including but not limited to plants with the horticultural names: morden pink, morden gleam, morden rose, the beacon, fire candle, brightness, lady sackville, Mr. Robert, Robert’s happy, roseum superbum, purple spire, rose queen, the rocket, dropmore purple and tomentosum.