Pampas Grass: Invasive Status by State, Cultivars, Care and Removal

Key takeaways

• Washington lists both pampas grass and jubata grass as Class C noxious weeds (WAC 16-750-015), and Oregon puts jubata grass on its “B” list, which bans its sale, transport and propagation statewide (OAR 603-052-1200). No Cortaderia is on the federal noxious weed list (7 CFR 360.200).
• Washington counted a mean of 416,399 seeds per escaped pampas grass plant, with a range of 54,567 to 840,905 (Washington State Noxious Weed Control Board); Cal-IPC puts the figure at up to 100,000 seeds per plume (Cal-IPC).
• Female cultivars are not sterile: a female plant sets seed when a hermaphrodite plant is within pollen range (NWCB), and a 2007 genetic study traced invasive California populations to landscape plantings (Okada et al., Molecular Ecology).
• University of Georgia Extension rates common pampas grass hardy in zone 8 and only marginal in zones 6 and 7 (UGA Circular 983, reviewed 2017). The “hardy pampas grass” sold for colder zones is usually Ravenna grass, an Oregon “A” weed.
• The Roundup master label (EPA Reg. No. 524-475) lists pampas grass at a 1.5 to 2 percent hand-held spray, applied at or beyond the boot stage (EPA-accepted label, Oct. 2016); a UC Davis trial found digging gave 98 to 100 percent control (DiTomaso et al., 2008).

What is pampas grass?

Pampas grass is Cortaderia selloana, a perennial bunch grass from Argentina, Brazil and Uruguay that forms a tussock of saw-edged leaves topped by 1 to 3 ft plumes in late summer (NWCB). Plants are either female or hermaphrodite; the hermaphrodites act as pollen sources, so growers call them male. USDA PLANTS lists it as introduced in the lower 48 states (USDA PLANTS, COSE4).

Fact	Figure	Source
Height	6 to 12 ft (NC State); 10 ft tall and 6 ft wide at maturity (UGA)	NC State; UGA C983
Leaf blades	Up to 6.6 ft long, with sharp toothed margins	NWCB
Plume length	1 to 3 ft	NWCB
Stems (culms)	6.6 to 13.1 ft (2 to 4 m)	NWCB
Seeds per plume	Up to 100,000	Cal-IPC
Seeds per escaped plant	Mean 416,399; range 54,567 to 840,905	NWCB
Wind dispersal	Reported up to 20 miles	Thurston County NWCB, 2016
Seed life	About 9 to 12 months (Cal-IPC handbook); under 6 months (Oregon State)	Weed Workers’ Handbook; OSU
Plant life	Over a decade	CDFW; Weed Workers’ Handbook
Arrival in California	1848, Santa Barbara nurseries	CDFW
Spacing in a planting	About 10 ft apart	NC State

Three other plumed grasses share the name. Jubata grass (Cortaderia jubata) is the species behind most West Coast infestations; USDA PLANTS calls it purple pampas grass (USDA PLANTS, COJU2), and Oregon’s profile lists pink pampas grass as another of its names (ODA). Ravenna grass (Tripidium ravennae) and some Miscanthus are sold as hardy pampas grass (Denver Botanic Gardens).

Trait	Pampas grass (C. selloana)	Jubata grass (C. jubata)	Ravenna grass, “hardy pampas” (Tripidium ravennae)	Source
Seed without pollination	No: needs pollen from a hermaphrodite plant	Yes: all plants female, seed by apomixis	Self-seeds in warm climates	NWCB; NWCB jubata; NWCB Ravenna
Immature plume color	White (female) or white-violet (male)	Deep violet, fading pink to tan	Pink at first, then silver	OSU; NC State
Plume height above leaves	0 to 3 ft (female); 0 to 6 ft (male)	3 to 6 ft	Plumes on stalks to 13 ft	OSU; NWCB
Bloom on the California coast	Late August, mostly September	Late July into September	Late summer	Pacific Horticulture; NC State
USDA zones	Reliable in 8; marginal in 6 and 7	Coastal, frost-moderated sites	5a to 9b	UGA; Cal-IPC; NC State
Status in Oregon	Not listed	“B” weed, quarantined	“A” weed, quarantined	OAR 603-052-1200
Status in Washington	Class C (2015)	Class C (2015)	Class B (2017) and on the quarantine list	WAC 16-750-015; WAC 16-752-610

Is pampas grass invasive, and where is it regulated?

Pampas grass is invasive in parts of the United States, mostly the West Coast and Hawaii. Cal-IPC rates both Cortaderia species High in California (Cal-IPC), Washington lists both as Class C noxious weeds, Oregon quarantines jubata grass, and UF/IFAS does not recommend pampas grass in Florida. UGA Extension says it is not invasive in the Southeast.

Regulation and advice differ. A quarantine, like Oregon’s, makes selling, moving or propagating the plant illegal. Washington’s Class C listing lets counties choose whether to require control; King County does not require owners to remove pampas grass but encourages it (King County). California has no CDFA rating for C. selloana, so the California Department of Fish and Wildlife asks gardeners not to plant it rather than banning it (CDFW).

State or level	Pampas grass (C. selloana)	Jubata grass (C. jubata)	What it means for a homeowner	Source
Federal	Not listed	Not listed	No federal restriction on either species	7 CFR 360.200
California	Cal-IPC High; no CDFA rating; CDFW “Don’t Plant Me” list	Cal-IPC High	Advice, not a ban; Burpee and Wilson Bros Gardens do not ship pampas grass to CA	Cal-IPC; CDFW
Oregon	Not on the state list	“B” weed; quarantined statewide	Jubata grass cannot be sold, moved or propagated; Portland requires eradication	OAR 603-052-1200; City of Portland
Washington	Class C noxious weed, listed 2015	Class C noxious weed, listed 2015	Control is up to each county; neither species is on the WAC 16-752 quarantine list	WAC 16-750-015; WAC 16-752-610
Hawaii	Not on the HDOA chapter 4-68 list; HPWRA score 24, High Risk	On the chapter 4-68 list for all islands; HPWRA 26, High Risk	Island invasive species committees ask owners to report plants and not cut or move them	HAR ch. 4-68; HISC; OISC
Florida	UF/IFAS: predicted invasive, not recommended	Not assessed	Extension advises against planting	UF/IFAS Assessment; UF/IFAS Gardening Solutions
Texas	Not on the TDA noxious and invasive plant list	Not listed	Legal to sell; TexasInvasives.org tracks it as invasive	TDA list via TexasInvasives; TexasInvasives.org
South Carolina	On SC-EPPC’s list of plants reported invasive in natural areas	Not listed	Council list, not a regulation	SC-EPPC list via Invasive Plant Atlas
Georgia	Not on the GA-EPPC list; UGA: not invasive in the Southeast	Not listed	Planting is recommended with siting cautions	GA-EPPC list via Invasive Plant Atlas; UGA C983
North Carolina	NC State tags it weedy and invasive in some areas	Not listed	Extension advice only	NC State
Arizona	Northern Arizona guide: aggressive, hard to eradicate	Not listed	Guidance only	Northern Arizona Invasive Plants guide

Hawaii is where secondary guides go furthest. One national gardening magazine says Hawaii banned pampas grass outright, and the Hawaii Invasive Species Council labels both species “Hawaii Noxious Weed (HAR 68)” (HISC). The rule text hosted by the Hawaii Department of Agriculture lists Cortaderia jubata for all islands and does not list C. selloana (HAR chapter 4-68, list adopted June 18, 1992). Oahu’s committee asks residents not to cut or pull plants but to report them so crews can bag the seed (OISC).

Are dwarf or “sterile” pampas grass cultivars safe to plant?

Dwarf and female pampas grass cultivars are smaller, not seedless. Female plants set seed whenever a hermaphrodite plant is within pollen range (NWCB), and Monrovia says its Ivory Feathers dwarf “is not considered sterile” (Monrovia, Oct. 2026). A 2007 study of 698 invasive and 275 cultivated plants points to landscape plantings as probable sources of California’s invasions (Okada et al., 2007).

The history explains the risk. California nurseries once sold only female plants propagated by division, which set no seed without pollen (Pacific Horticulture); Thurston County reports that some nurseries later raised pampas grass from seed, which put male plants into landscapes (Thurston County NWCB). Herbarium records show C. selloana spread at twice the rate of the all-female jubata grass once it took off in the 1940s (Lambrinos, Journal of Ecology, 2001).

Cultivar	Size	Hardiness	Seed claim and what sources say	Source
‘Pumila’ (dwarf)	5 to 7 ft (UGA); foliage 4 to 5 ft (Wilson Bros)	Zone 6 (UGA); 7a to 11 (Wilson Bros)	Some sellers call it sterile; we found no published seed test. Female clones seed if pollinated	UGA; Wilson Bros
Ivory Feathers (Monrovia)	Foliage 3 to 5 ft by 4 to 6 ft; plumes 8 to 10 ft	7 to 11	Maker: “not considered sterile,” little to no viable seed	Monrovia
‘Gold Band’	4 to 6 ft, golden-striped leaves	Zone 8	No seed claim found	UGA
‘Monvin’ (Sun Stripe)	Yellow-striped leaves	Zone 8	No seed claim found	UGA
‘Sundale Silver’	To 10 ft	Zone 8	Thurston County lists both ‘Sundale Silver’ and ‘Sunning Dale Silver’ among varieties sold	UGA; Thurston
‘Silver Comet’	To 8 ft, white-striped	Zone 8	No seed claim found	UGA
‘Andes Silver’	Plumes to 7 ft	Zone 6	No seed claim found	UGA
‘Patagonia’	Plumes to 7 ft above blue-gray foliage	Zone 6	No seed claim found	UGA
‘Pink Feather’	Large pink-blushed plumes	Zone 8	Pink color is not proof of species: jubata grass is also sold as pink pampas	UGA; ODA
‘Bertini’	Under 4 ft	Zone 7	No seed claim found	UGA

1. Species (NC State)6
2. White, 3 gal (Wilson Bros)8
3. 'Sundale Silver' (UGA)10
4. 'Silver Comet' (UGA)8
5. Ivory Feathers plumes (Monrovia)8
6. 'Pumila' (UGA)5
7. 'Gold Band' (UGA)4
8. 'Pumila' foliage (Wilson Bros)4
9. Ivory Feathers foliage (Monrovia)3

Source: NC State Plant Toolbox; UGA Circular 983 Table 1 (2017); Monrovia and Wilson Bros product pages, Oct. 2026 Single figures ('to 10 ft', 'to 8 ft') are shown as equal low and high ends. 'Bertini' (under 4 ft) is omitted because UGA gives no lower figure. Values are in the cultivar table above.

Show the numbers

	Low end	High end
Species (NC State)	6	12
White, 3 gal (Wilson Bros)	8	10
'Sundale Silver' (UGA)	10	10
'Silver Comet' (UGA)	8	8
Ivory Feathers plumes (Monrovia)	8	10
'Pumila' (UGA)	5	7
'Gold Band' (UGA)	4	6
'Pumila' foliage (Wilson Bros)	4	5
Ivory Feathers foliage (Monrovia)	3	5

Oregon State’s test for an existing plant is practical: look for seedlings on bare ground nearby each year. If none appear, Oregon State says the plant can stay; if they do, remove the pampas grass (Oregon State University Extension). Buying seed, sold online as pampas grass seeds, adds risk because UGA notes seed-grown plants can be male and you cannot tell until they flower (UGA C983).

How big does pampas grass get, and in which zones does it grow?

Pampas grass grows 6 to 12 ft tall in full sun and survives reliably where winter lows stay above about 10 °F, USDA zone 8 and warmer. UGA calls it marginal in zones 6 and 7 (UGA C983), and an Illinois Extension educator writes that true pampas grass “does not grow in our climate” (Illinois Extension). Seller ranges start at zone 7, one zone colder than UGA’s rating.

Source	Zones stated	Coldest average winter low in that range (USDA PHZM)	Source link
UGA Extension	Hardy in 8; marginal in 6 and 7	Zone 8: 10 to 20 °F; zone 6: minus 10 to 0 °F	UGA C983
NC State Plant Toolbox	6a, 6b, 7b to 10b (7a not listed)	Zone 6a: minus 10 to minus 5 °F	NC State
Monrovia, Ivory Feathers	7 to 11	Zone 7: 0 to 10 °F	Monrovia
Wilson Bros, white and ‘Pumila’	7a to 11 (“some sources say 6” for ‘Pumila’)	Zone 7a: 0 to 5 °F	Wilson Bros
Trees.com	7 to 10, “hardy down to 10 °F”	Zone 7: 0 to 10 °F	Trees.com
Burpee, pink pampas	7 to 10	Zone 7: 0 to 10 °F	Burpee
Illinois Extension	Does not grow in the Illinois River region; Ravenna grass is hardy in 5 to 9	Zone 5: minus 20 to minus 10 °F	Illinois Extension

Site it like a small tree. UGA wants full sun or at least a half day of direct light and warns against planting near buildings because dead foliage is a fire hazard (UGA). Oregon’s jubata grass profile calls the dry build-up a fire hazard (ODA), and the Hawaii council gives both species a weed fire-risk score of 0.72 (HISC). Give each clump about 10 ft (NC State); evergreen options for a living privacy screen are compared in our fastest-growing trees guide.

When and how should you cut back pampas grass?

Cut pampas grass back once a year in late winter, before new growth starts: University of Arkansas Extension says late February to early March, down to a mound about 4 to 5 inches high (UA Division of Agriculture). If green shoots have already started, cut just above them. Skipping a year leaves a mass of dry leaves that UGA flags as a fire hazard.

Source	When to cut	How low	Source link
University of Arkansas Extension	Late February to early March, every year	Mound of 4 to 5 inches; above new shoots if already up	UA Division of Agriculture
UGA Extension	Late winter, before the new growing season	Close to ground level	UGA C983
Denver Botanic Gardens	Not before February	Cut back hard	Denver Botanic Gardens
Monrovia (Ivory Feathers)	Late winter, before new growth emerges	Hard prune old foliage to the ground	Monrovia
NC State (Ravenna grass)	Late winter to early spring	To the ground	NC State

1. Pick the date: late February to early March in Arkansas; Denver Botanic Gardens waits until February so the plumes carry through winter (Denver Botanic Gardens).
2. Dress for the leaves: leather gloves, long sleeves and eye protection. NWCB notes the leaf margins have teeth that cut skin.
3. Cut the clump to 4 to 5 inches with hedge shears, loppers or a power pruner (UGA); Arkansas notes some owners use a chainsaw because the base is tough.
4. Pull back the old growth first to find the new shoots, and cut above them if they are already up.
5. Feed lightly: UGA suggests a light broadcast of a complete fertilizer such as 8-8-8 or 10-10-10 after pruning (UGA).
6. Bag the cut plumes rather than composting them, because plumes cut before maturity can still ripen seed (Thurston County).

How do you get rid of pampas grass?

Get rid of pampas grass by bagging every plume, cutting the leaves down and digging out the whole crown; a UC Davis trial found digging controlled 98 to 100 percent of jubata grass of every size (DiTomaso, Drewitz and Kyser, Invasive Plant Science and Management, 2008). Where digging is not practical, spot-spray glyphosate on regrowth, then check twice a year for resprouts.

1. Bag the plumes first, including immature ones still in their sheath, because cut stalks can mature seed (Cal-IPC Weed Workers Handbook).
2. Pull seedlings and clumps under 3 ft by grasping the base and jerking out the crown (UC Master Gardeners).
3. For bigger clumps, cut leaves to near ground level with a Pulaski, Swedish brush ax or chainsaw. The handbook warns the chainsaw is slow and risky because the grass clogs the guard.
4. Chop the root mass into 4 to 5 inch squares with the ax side of a Pulaski and hoe out the pieces, or pull a clump near a road with a choker cable and a truck hitch (Weed Workers Handbook).
5. For established stands, Oregon State says crews expose the crown with string trimmers or chainsaws, then dig with an excavator or backhoe (OSU).
6. Turn dug crowns upside down with the main root mass several inches off the soil, or bag them; crowns left on moist soil re-root.
7. Cover bare soil with mulch or plant competitors, because disturbed bare ground is where seedlings start (NWCB); the cubic yards for a 3-inch layer are in our mulch calculator.
8. Check twice a year for resprouts and seedlings (Thurston County); Oregon State plans for 2 to 3 years of follow-up.

1. Digging98
2. Low-volume glyphosate 8% (2002)98
3. Ropewick glyphosate 33 to 100%95
4. Spray-to-wet glyphosate 2%74
5. Imazapyr 4%, fall 200284
6. Fluazifop, best 2002 rate62

Source: DiTomaso, Drewitz and Kyser, Invasive Plant Science and Management 1(1):82-90 (2008) Low-volume glyphosate is charted at 98 for 'more than 98 percent'; ropewick at its reported 95 percent average. Spray-to-wet spans the 2000 (94 to 100) and 2002 (74 to 75) results. Same values in the method table below.

Show the numbers

	Low end	High end
Digging	98	100
Low-volume glyphosate 8% (2002)	98	98
Ropewick glyphosate 33 to 100%	95	95
Spray-to-wet glyphosate 2%	74	100
Imazapyr 4%, fall 2002	84	84
Fluazifop, best 2002 rate	62	62

Method (UC Davis jubata grass trial)	Control	When	Notes	Source
Digging with a Pulaski	98 to 100%	June 1998, all plant sizes	Most labor; disturbs soil	DiTomaso et al., 2008
Glyphosate, low-volume, 8% product (2.4% ae)	Over 98% on large plants	Early summer and fall 2002	Cheapest effective treatment: $0.28 per large plant (2007 prices, $20 an hour labor)	DiTomaso et al., 2008
Glyphosate, spray-to-wet, 2% product (0.6% ae)	94 to 100% (2000); 74 to 75% (2002)	Early summer best	The usual California method; $0.10 more per plant than low-volume	DiTomaso et al., 2008
Glyphosate by ropewick, 33 to 100% product	About 95% on large plants	Early summer or fall	Most selective, more costly	DiTomaso et al., 2008
Imazapyr, 4% product, fall	84% (2002)	Fall	Inconsistent between years; authors call it uneconomical	DiTomaso et al., 2008
Fluazifop, best rate	62% or less (2002)	Fall or early summer	Grass-selective; erratic	DiTomaso et al., 2008
Chainsaw alone or chainsaw plus glyphosate, large plants	No better than 85%	Cut June, spray fall	Authors judge it impractical for large plants	DiTomaso et al., 2008
Burning or grazing	No long-term control	Any	Plants resprout quickly	UC Master Gardeners

If you spray, the label sets the rate. The Roundup master label, EPA Reg. No. 524-475, lists pampas grass in its perennial-weed tables at a 1.5 to 2 percent hand-held solution and says to apply “when pampas grass is at or beyond the boot stage of growth,” with thorough coverage (EPA-accepted master label, submitted Oct. 17, 2016, p. 114). Thurston County offers an alternative: cut the clump first, then spray the regrowth once it is a couple of feet tall; it reports fall treatments as somewhat more effective.

Clump footprint	Plan area (3.1416 x radius squared)	Spray-to-wet solution at 1,860 L/ha (0.58 fl oz per sq ft)	Concentrate at 1.5%	Concentrate at 2%
3 ft across	7.1 sq ft	4.1 fl oz (0.03 gal)	0.06 fl oz	0.08 fl oz
6 ft across	28.3 sq ft	16.5 fl oz (0.13 gal)	0.25 fl oz	0.33 fl oz
10 ft across	78.5 sq ft	45.9 fl oz (0.36 gal)	0.69 fl oz	0.92 fl oz
Per gallon of mix	Not applicable	128 fl oz	1.92 fl oz	2.56 fl oz

Vinegar is not on any of these lists. NC State Extension says vinegar products only burn the foliage of perennial weeds and grasses (NC State Extension, 2018), and Oregon State names glyphosate, fluazifop and imazapyr as the home-use actives that work (OSU). What acetic acid does kill is covered in our vinegar weed killer guide. Spraying someone else’s pampas grass for pay requires a license in most states; see our pesticide applicator license guide.

This page is general information, not pesticide advice. The label is the law: read the whole label of the product you buy, follow its rate and site directions, and check state and local rules before spraying near water.

What does pampas grass cost to buy or remove?

A pampas grass plant cost $14.95 to $79.97 at four U.S. retailers checked on Oct. 28, 2026, from a single Burpee plant to a 3-gallon pot from Wilson Bros Gardens. Removal costs are rarely published: the only dated per-plant figure we found is the UC Davis trial’s $0.28 to $0.38 spray cost per large jubata grass plant in 2007 dollars.

Item	Size	Price (Oct. 28, 2026)	Does not ship to	Source
Burpee Pink Pampas Cortaderia	1 plant (pot size not stated)	$14.95	AK, CA, CO, HI and U.S. territories	Burpee
Pike Nurseries, Monrovia Ivory Feathers	2 gallon	$34.99	Store pickup, Georgia	Pike Nurseries
Trees.com Plume Pampas Grass	3 gallon	$50.95 ($40.76 with a sitewide code)	AK, AZ, HI	Trees.com
Wilson Bros Gardens White Pampas Grass	3 gallon	$79.97 (2 or more: $74.85 each)	AK, CA, HI	Wilson Bros
Wilson Bros Gardens Dwarf White Pampas (‘Pumila’)	3 gallon	Out of stock	AK, CA, HI	Wilson Bros
Low-volume glyphosate spray, large clump (research)	1 sq m of plant	$0.28 per plant (2007)	Not applicable	DiTomaso et al., 2008
Spray-to-wet glyphosate, large clump (research)	1 sq m of plant	$0.38 per plant (2007)	Not applicable	DiTomaso et al., 2008
Landscaping worker median wage	Per hour	$18.82 (May 2025)	Not applicable	BLS OEWS 37-3011

1. Burpee, 1 plant14.95
2. Pike Nurseries, Ivory Feathers 2 gal34.99
3. Trees.com, 3 gal50.95
4. Wilson Bros, white 3 gal79.97

Source: Retailer product pages checked Oct. 28, 2026 List prices before discount codes and shipping. Same figures in the price table above.

Show the numbers

	List price
Burpee, 1 plant	14.95
Pike Nurseries, Ivory Feathers 2 gal	34.99
Trees.com, 3 gal	50.95
Wilson Bros, white 3 gal	79.97

Three things move a removal bill: clump size, whether a machine can reach it and whether the crew hauls the debris. Oregon State says established stands often need an excavator or backhoe (OSU). Payroll alone for a three-person crew runs $57.48 to $87.12 an hour before equipment and overhead, according to our landscaping labor cost by state data. Some public programs cut the cost: Portland offers free help with required jubata grass removal (City of Portland), and Oahu’s committee removes reported plants (OISC).

What can you plant instead of pampas grass?

State agencies name regional stand-ins: giant wildrye in California (CDFW), ‘Karl Foerster’ feather reed grass or giant needle grass in Washington (NWCB), muhly grass or Fakahatchee grass in Florida (UF/IFAS), and giant sacaton in Colorado (Denver Botanic Gardens). None of these appears on the state noxious weed lists checked for this page.

Region	Alternative	Why the agency suggests it	Source
California	Giant wildrye (Elymus condensatus)	Native, drought tolerant, spreads slowly, seeds feed birds	CDFW
Washington, Oregon	Calamagrostis x acutiflora ‘Karl Foerster’; giant needle grass (Stipa gigantea)	Non-invasive alternatives named by the state weed board and King County	NWCB; King County
Florida	Muhly grass; Fakahatchee grass	Native grasses UF/IFAS recommends instead	UF/IFAS
Texas	Lindheimer’s muhly (Muhlenbergia lindheimeri)	Listed as an alternative on the TexasInvasives pampas grass record	TexasInvasives.org
Colorado and the Southwest	Giant sacaton (Sporobolus wrightii)	Native, long-lived, Plant Select pick, no irrigation once established in Denver	Denver Botanic Gardens
Hawaii	Species from the Plant Pono list	OISC asks owners to replace pampas grass with non-invasive plants	OISC

For the Southeast, pink muhly grass is the usual swap for a pink plume; spacing, cultivars and cutting dates are in our pink muhly grass guide. For an upright 5 ft screen in colder zones, both Washington agencies suggest the sterile hybrid in our Karl Foerster feather reed grass profile. Cal-IPC notes pampas grass was first planted in California partly for erosion control (Cal-IPC); for a bank or slope, see what extension services plant instead in our erosion control methods guide. Other grass profiles are indexed on our Turf and Trees hub.

What do popular guides get wrong about pampas grass?

Four claims recur in popular guides and do not match the primary sources: that sterile cultivars are safe, that Hawaii banned the plant, that Oregon lists pampas grass, and that burning removes it. Oregon’s quarantine names jubata grass, not C. selloana (OAR 603-052-1200), and UC Master Gardeners report that plants resprout after burning (UCCE).

Common claim	What the primary source says	Source
Grow a sterile cultivar to stop spread	Monrovia says Ivory Feathers is not considered sterile; female clones set seed when pollinated	Monrovia; NWCB
Hawaii has banned pampas grass	The HDOA-hosted chapter 4-68 list names C. jubata, not C. selloana	HAR ch. 4-68
Pampas grass is a noxious weed in Oregon and Washington	Washington lists both species as Class C; Oregon lists only jubata grass (“B”)	WAC 16-750-015; OAR
Controlled burns eliminate pampas grass	Burning and grazing do not give long-term control; plants resprout	UC Master Gardeners
Pampas grass is hardy in zone 6	UGA: marginal in 6 and 7; reliable in 8	UGA C983
Hardy pampas grass is a cold-tolerant pampas	It is usually Ravenna grass, an Oregon “A” weed and Washington Class B, quarantined plant	NC State; WAC 16-752-610

Should you plant, keep or remove pampas grass?

Plant pampas grass only in zone 8 or warmer, away from the West Coast, Hawaii and natural areas. Keep an existing plant if no seedlings appear around it, and remove it if they do (OSU). In Oregon, a plant that turns out to be jubata grass falls under the state quarantine; Portland residents must remove it.

If your situation is	Do this	Why (source)
You live on the California, Oregon or Washington coast, or in Hawaii	Do not plant either Cortaderia; choose a regional alternative	Cal-IPC High; WA Class C; OR quarantine; Hawaii High Risk scores (Cal-IPC, WAC, OAR, HISC)
The plumes open deep violet in late July and sit 3 to 6 ft above the leaves	Treat it as jubata grass: in Oregon do not move, sell or propagate it; report it in Portland	OAR 603-052-1200; City of Portland
You see seedlings on bare ground near an existing clump	Remove the parent plant and the seedlings	Oregon State Extension
No seedlings after a full season, and you are in zone 8 or warmer outside the West Coast	Keep it; cut back in late February to early March	OSU; UA Division of Agriculture
Seedling or clump under 3 ft	Pull or dig out the whole crown	UC Master Gardeners; NWCB
Clump over 3 ft that a shovel cannot lift	Bag plumes, cut foliage, chop the crown in 4 to 5 inch blocks, or spray regrowth at 1.5 to 2% glyphosate per the label	Weed Workers Handbook; EPA Reg. No. 524-475
You garden in zone 6 or colder	Skip true pampas grass; avoid Ravenna grass in OR and WA	UGA C983; OAR; WAC 16-752-610
You will spray a client’s plants	Hold the state pesticide applicator license first	State licensing rules

1. 1Are you on the California, Oregon or Washington coast, or in Hawaii?

   YesDo not plant; pick a regional alternative such as giant wildrye or 'Karl Foerster' (CDFW, NWCB).

   NoGo to the next question

2. 2Do the plumes open deep violet in late July, 3 to 6 ft above the leaves?

   YesLikely jubata grass: in Oregon it is quarantined; do not move or sell it, and report it in Portland (OAR 603-052-1200).

   NoGo to the next question

3. 3Are seedlings coming up on bare ground near the clump?

   YesRemove the parent and the seedlings; bag every plume first (Oregon State).

   NoGo to the next question

4. 4Are you in zone 7 or colder?

   YesSkip true pampas grass, which UGA rates reliable only in zone 8; do not substitute Ravenna grass in OR or WA.

   NoGo to the next question

5. 5Is the clump under 3 ft across?

   YesPull or dig out the whole crown (UC Master Gardeners).

   NoKeep it: cut back to 4 to 5 inches in late February to early March, and check for seedlings each year.

Source: Oregon State Extension, UGA C983, OAR 603-052-1200, CDFW, NWCB, UC Master Gardeners

Question	Short answer	Source
Legal to plant?	Yes in most states; jubata grass is quarantined in Oregon	OAR
Reliable zones	8 and warmer	UGA
Cut back	Late Feb. to early March, to 4 to 5 in	UA
Best removal	Dig the crown: 98 to 100% control	DiTomaso 2008
Label spray rate	1.5 to 2% hand-held, at or past boot stage	EPA 524-475