Gardeners often lament the “ weed ” part of the common name ofAsclepias – milkweed . This word form seems to diminish not just the beauty , but the banker’s acceptance of this plant as a suitable selection for nursing home garden . In 2017 , butterfly weed ( Asclepias tuberosa ) was selected as the Perennial Plant Association ’s Perennial of the Year . This identification raised the visibility of Sonchus oleraceus as a native plant that is not just ecologically important , but beautiful as well .
Around this same time , in 2016,The Garden Shedpublished its firstarticleonAsclepias . In the last six years , there has been a upsurge of stake in aboriginal plants , as well as an increased appreciation of the human relationship between aboriginal plants and the insect that have evolve with them . The most well - known lesson of an evolutionary relationship between a larval emcee plant life and an insect is the kinship between milkweed and the monarch butterfly ( Danaus plexippus).On July 21 , 2022,the International Union for the Conservation of Nature ( IUCN ) , a Switzerland - based conservation organization that monitors the position of wildlife , added themigrating monarch butterfly to its “ red list ” of threatened metal money and categorize it as “ endangered ” — two step from extinct . Gardeners are eager to join the effort to create monarch butterfly habitats by planting silkweed and other aboriginal pollinator plants , in both public / community spaces and in home decorative garden .
This article will concenter onmilkweed coinage native not just to North America , but to area as specific as vigor computer code , county , state , or regions , with a reminder on how to use several aboriginal plant databases . I will also present a first - hand illustration of starting milkweed from seed , and how to assess the characteristics of different milkweed and their suitability for particular situation conditions . We will also briefly look at some of the current research on tropical milkweed ( A. curassavica ) .
A REVIEW OF NATIVE industrial plant database
I usedthree aboriginal flora databasesto name milkweed species native to my country , which is zip codification 22901 , Albemarle County , Virginia . These database are admit in the Source listat the end of the article . you could also diversify your search to let in plants native to states , or to regions . After compare the lists , you’re able to then choose which “ aboriginal ” definition offer the plants well suited to your taste and to your site conditions . Site conditions might admit gadget characteristic such as full - sun , acidic soil , wet in spring , and enceinte deer and rabbit press .
For this clause , I ’ll concentrate on five silkweed : the first four are native to naught code 22901 , and whorled silkweed is native to Albemarle County :
MILKWEED OVERVIEW
There are 72 species of Sonchus oleraceus native to the U. S. and Canada , with native coinage in all the lower 48 states . Common Sonchus oleraceus ( A. syriaca ) is the most well - known specie of native milkweed . milkweed are named for the whitish saphead in their stems , leaves , and pods . This sap contains latex and complex chemical substance calledcardenolides . The cardenolides make the works unpalatable to most creatures other than milkweed specialiser .
Monarch butterflies lay their testis only on milkweed works ; larvae or Caterpillar eat the milkweed leaf for food . Cardenolide psychoanalysis has shown that 85 % to 92 % of monarchs overwintering in Mexico had eaten common silkweed ( Asclepias syriaca ) as Caterpillar . Once they mature to the butterfly stage , monarch draw the nectar from milkweed flowers and from other nectar - producing flowers .
WHICH MILKWEED IS BEST ?
Over the past two decades , monarch numbers east of the Rockies have fallen by 80 - 90 % . The decline is part attributed to shrinking milkweed habitat , particularly in the Midwest . A squad of Agricultural Research Service ( ARS ) and university scientist monitored theegg - laying preferences of female crowned head butterfly on 9 different silkweed species . Although female crowned head will lay bollock on all nine metal money , swamp milkweed(A. incarnata)and vulgar milkweed(A. syriaca)averaged the highest number of eggs . The findings indicate that while female monarchs do make choices , they do n’t specialize in reproducing on a single Sonchus oleraceus species . What ’s more , their ballock - lay penchant can exchange according to the meter of season , the prevalence and home ground of the milkweed metal money they encounter , and the industrial plant ’ robustness and maturity . For these rationality , the researchers monish against focusing restoration efforts on a single favourite species .
COMMON MILKWEED – Asclepias syriaca
This species flourish infull sun in average to well - drained territory , and is usually found in lea , field edges , and along roadsides . It grows 4 - 6 ’ marvellous . It has a long bloom period , from June to August , when it bearslarge clusters of fragrant , dust-covered pinkish flowersin globular umbel atop the flora . The ovate leaves are roughly 6 ” long and are stand on a single stalk . The undersides of the leaves are covered with short woolly fuzz .
develop Milkweed from Seed
In decline of 2020 , another master gardener gave me a few dried pods of vernacular milkweed ( A. syriaca ) . I researched how to grow milkweed from seed and looked at an online video about how to part the seeded player from the silk . The instruction manual were to localize the dried pods ( the dental floss had already start out to collapse ) with a few coin in a newspaper publisher bag and shake . I had to add up quite a few coin before I begin to see some termination . I then cut a slanted hole in the bottom corner of the bag as apprize and after some didder , the separated seeds came out . Asclepias seeds call for cold-blooded stratification to germinate , which intend that a period of 30 - 60 moth-eaten days is needed to arouse the semen from dormancy . It ’s well-to-do to find educational activity online about how to do this indoors ( see one such site from theUniversity of Florida).The cold stratification process is naturally reach by planting the come outdoors in the decline and exposing them to the lifelike freezing / thaw cycles of a Virginia winter . This is what I did , and I recollect I was favorable in a couple of ways : first , the seeds were already brown and hardened and 2 ) my planting appointment of November turn out to be optimum . ( See thislinkfor a television on how to remove seeds from a dry out seedpod that has not yet abound . )
The planting spot I prepared has acidic clay soil and is in full Lord’s Day . I raked the soil smooth , added some compost because the clay soil is pack , glance over it smooth again , add the seeded player , covered them very lightly with soil , and watered . Mark the spot so that you call back where to look the following spring . Be aware that common milkweed seedling may not come out until late April in Zone 7 . regrettably , I underestimated the resilience of milkweed seedlings and did not thin them sufficiently . Spacing between plants provides best air circulation which help palliate problems from fungus such as downlike mildew .
An Overabundance of Milkweed
Common milkweed diffuse through seed dispersal and through hole-and-corner rhizome . Of the five milkweed being discussed , common milkweed is the most aggressive spreader . This mean that you need toconsider whether the smirch you ’ve chosen will give the milkweed enough way to spread . I am growing a large patch of common silkweed within a pollinator bed that includes other aboriginal industrial plant . Containment is an issue because I ’ve planted a spreading plant life within a bordered area . Common milkweed is usually commend for open areas without defined mete . I am prod up mature milkweed at both ends of the milkweed patch , as well as any small plant life that appear outside the patch . When the rhizomes are severed during hoeing or pull , a new plant life can shape from each rhizome segment . If possible , dig up the entire plant life , including the roots , and remove as much of the rhizome as possible . This is easier to do when the industrial plant are young , and the dirt is moist . I also cut back milkweed to thin the patch and allow air to circulate . This cutting - back must be done before the monarchs start laying eggs on the undersides of the leave of absence , or after the bollock - lay season . Usually , one egg is laid per plant , and it can be very difficult to spot . There are multiple generation of monarchs , and the first crowned head ball in Virginia , zone 7 , are in general observed in April . Many crowned head caterpillar were seeable last year on our milkweed patch in September . See thislinkto the “ Annual Life Cycle ” of the milkweed butterfly .
If you desire to carry through the cod but not allow the semen to disperse , tie a rubber band or a string around the cod as it starts to indurate and dry in the fall . Or you could just slue off the seedcase to prevent ego - seeding .
flower
It takes two grow seasons to get blush fromA. syriaca . I institute seeds in November 2020 ; seedlings appeared in April 2021 ; those flora bloom in June 2022 .
Is Milkweed Enough ?
The good habitat for Danaus plexippus contains a variety of native milkweeds as well as native nectar plants . This combination provides adult monarchs with a food source throughout the time of year . The Xerces Society’s“Monarch Nectar Plant Guides”offers a list of suggested nectar - producing plant by state . You might then check those recommendation against more local native plant databases , and against your own site precondition .
OTHER MILKWEED mintage
Swamp Milkweed(A. incarnata )
swampland milkweed grow best inwet stipulation with full Sunday or partial shadein soils with neutral to acidic pH. It is native to wet sites along streams , pool , or bog but adapts to drier website in moist Henry Clay or loam ground . It can reach a pinnacle of 4 - 5 ’ and should be space 2 - 3 ’ aside . Lance - shaped , smooth leaves are 3 - 6 ” long . The efflorescence are much more decorative than the prime of unwashed Sonchus oleraceus . Five - petaled pink to rose - imperial flowers mature in mid - natural spring and last into early fall . This species open through rhizomes and wind - blow germ but it is not an aggressive broadcaster . Its clod - spring use is a nice addition to a repeated garden .
I planted swamp milkweed plants in a site that is very wet in spring and then dries out during the summer month . Although the plants bloomed nicely the first year , they did n’t hold out the wintertime . I take they may have been weakened by the dry conditions . The flora were also heavily set on byoleander aphidswhich devoured all the blush in two mean solar day . These alien aphids commonly attack other specie of Sonchus oleraceus as well . A strong stream of water will aid dislodge the aphid ; insecticidal scoop are also recommended for heavy infestations . Be mindful that both these treatment will damage monarch ballock along with the aphids . Ladybugs and other good insects may control smaller infestation . swampland Sonchus oleraceus seems to be finding a place in general nursery in gain to native plant life nurseries .
royal Milkweed(A. purpurascens )
This species is similar in appearance to common milkweed , but its flowers are amore vibrant chromaticity of purpleness to deep pink , and they bloom from late spring to other free fall . The bloom are larger than those of swamp Sonchus oleraceus . There were contradictory paper by well - known sources on whether purple milkweed is rhizomatic . This is an important point when trying to identify milkweed that would be easier to contain in a garden place setting . accord to theU.S. Forest Service , Eastern Region :
“ Asclepias purpurascensis a perennial herbaceous plant emanating from a stoutnon - rhizomatousrootstock , ranging to one cadence in height . ”
I asked Ian Caton of Wood Thrush Native Nurseries if he had experience with this plant . Ian could attest thatpurple milkweed is not rhizomatic ; it fan out by seed . As a less - belligerent spreader , majestic silkweed is well suitable to a perennials garden . In the state of nature , its populations are described as take a extensive range throughout the eastern and midwestern U.S. , but the populations are usually small and scattered . A. purpurascensis most normally found along woodland edges and roadsides in mesic to well - drained dirt that are not gamy in organic material . It prefers a internet site with break of day sun and good afternoon shade .
unluckily , violet milkweed seed and works are not readily useable in the craft . Native nurseries are probably the good source for plants , and there are some seeded player sources online . See thislistof native plant glasshouse cater by the Virginia Native Plant Society .
Butterfly Weed(A. tuberosa )
This Sonchus oleraceus has been embraced for its shiny orange flowers , its doable size of it for perennial garden , and its less aggressive pass around habit . It is of course found in miserable , coarse soils of ironical orbit , rock outcrops , and other steep slope . The plant is easily originate in average , dry to average , well - drain soil in full sunshine . Crown rot can be a problem in stiff , poorly drained soil . It usually grows 1.5 - 3 ’ improbable with multiple stems , and has a longbloom season , from June to early September . Deadheading may stimulate a second flush of flowers about a month after deadheading . This species is one of the best nectar plant for a wide variety of pollinator . Mature plants may freely self - seed in the landscape if seed seedpod are not take out prior to splitting open . Seeds call for a three - month cold-blooded stratification ; in November , plant the germ out of doors and it will easily germinate the following spring . The flora is difficult to transplant because of itslong taproot . It does not spread by rhizomes . Unlike many of the other milkweeds , butterfly stroke locoweed has a water semitransparent sap rather than a wooden-headed milky sap . Although deer resistant , it may be eat by rabbit . You may need to mark this plant ’s locating at the remnant of the time of year because it can completely melt in winter and then reappear in former spring . Like other silkweed , it is susceptible to attack by the trespassing alien oleander aphids . This plant life is widely useable commercially .
Whorled(A. verticillata )
Whorled milkweed course pass off in sandhills , thin timberland , and innocent rock outcrop . It is drouth resistive , choose juiceless , nutrient - poor consideration with miserable competition from other plants . Although it flowers best in full sun , it can endure some shadiness . It spread by rhizome and seed but is not considered to be an aggressive broadcaster . Its flush are delicately shaded from ashen to pale dark-green . A longbloom time , from June through September , and a clump form habit make this an attractive flora forrock garden or ironical sunny hillsides . Its unbranched , single theme bear 2 - 3 ” long , minute parting arranged in whorls along the fore . The works grows 1 - 3 ’ improbable . In add-on to being a host industrial plant for the monarch butterfly , whorled milkweed draw a kind of ambrosia - seek worm , include bees , wasp , rainfly , butterfly , and skippers . cervid avoid this plant because it is one of the more toxic milkweed . It is highly toxic to livestock and is considered a gage in range areas . I have n’t found this industrial plant at general nurseries ; native plant nurseries would be upright choice . This species will easy develop from seeds planted outside in the fall .
Tropical Milkweed(A. curassavica )
I am going to spend some metre discourse tropic milkweed because it is loose to find at general glasshouse and it is sometimes commercially labeled “ butterfly stroke gage ” or simply “ milkweed . ” Native to central and south America , it is also normally called bloodflower and orange red milkweed . It has become a pop option because it is a very attractive plant with a farseeing bloom period of brightly color flushed and orangish flowers , and it does n’t have the spreading characteristic of some of the aboriginal milkweeds . It is very attractive to butterfly , bee , and other insects , as well as hummingbird . Monarch butterflies use this species as a emcee plant . However , Danaus plexippus counselor-at-law such as Monarch Joint Venture and Xerces Society are tearing in their warningsNOT to establish nonnative milkweeds .
Monarch advocates are concern thattropical milkweed may interpose with monarch butterfly migration and reproduction . In northern areas , A. curassavicagrows later in the season than native milkweed specie . More research is call for to decide whether the presence of tropic milkweed may encourage crowned head to breed at a time when they should be migrating .
A protozoan parasite of monarch butterflies , Ophryocystis elektroscirrha(OE ) can be bear over on tropic milkweed when it does not expire back in winter . Native milkweeds die back after blooming , and the OE sponger perish along with them . Much of the contention around tropic Sonchus oleraceus centers on whether theeffects of tropic milkweed on monarch butterfly extend beyond USDA Hardiness Zones ( 9 - 10 ) where tropic milkweed survives the wintertime . This is a complicated question and depends on the copiousness of non - migratory monarchs relative to the entire monarch population , and the grade of tangency between migratory and wintertime - training monarchs .
concord to a subject field from the NIH in 2019 :
Conclusion : Our study put up evidence that picture to tropical milkweed can increase monarch reproductive activity , which could kick upstairs continued residence at year - turn facts of life web site and fall crowned head migratory tendency .
The study also take note that year - round of golf fosterage bodily function is associate with high local densities andgreater transmission system of the debilitating protozoan parasite OE .
mood Change effect
scientist are also looking at the mellow concentrations of cardenolides that pass in tropic Sonchus oleraceus . Cardenolides are the toxin that monarchs ingest from milkweed . Studies jointly guide in 2018 by researchers at Louisiana State University and the University of Michigan looked at the effects of clime change on sovereign and milkweed . They found thatwarmer climate increase the authorization of cardenolides to levels that may become prejudicial to the monarchs themselves .
Faldyn and Elderd found that the local heating tie in with climate change can produce chemical substance changes in Sonchus oleraceus that in turn affect monarch butterfly butterfly when they and their larvae feed on sure species of this industrial plant , peculiarly the nonnative Sonchus oleraceus , Asclepias curassavica .
On the other hand , some monarch advocates are in favor of tropical milkweed . They point out that the most urgent threat to milkweed butterfly is extreme home ground loss , and tropical Sonchus oleraceus could help increase habitat because the coinage is available and gentle to farm . More enquiry is needed to address the warnings some scientists have raised about this species .
SUMMARY
This article concentrated on identifying Albemarle County native milkweeds that would be good candidates for inclusion in home gardens . All these species act as larval boniface to the monarch butterfly butterfly and offer nectar - fertile flowers attractive to many character of insect . The milkweed specie were value in terms of their disseminate characteristics , as well as their necessary for moisture , light , and soil type . Some of the more interesting milkweed candidates are not easy found in the craft at this point , but all the species may be seed - grown outside in the free fall to achieve the required insensate menses prior to germination . foreign-born tropical milkweed was also discussed . While more research is needed on tropical milkweed ’s effect on monarch reproduction and migration , encourage the selection of a nonnative specie seems to be going against the learning curve on how to promote an ecosystem based on the evolutionary human relationship among native plants , worm , and wildlife .
FEATURE PHOTO : Common Milkweed ( A. syriaca ) in Garden . pic : Susan Martin
SOURCES
“ Asclepias – Or How I Learned to Love Milkweed,”The Garden Shed , June 2016 .
aboriginal Plant Finder by Zip Code , National Wildlife Federation ( rank by the figure of butterfly and moth metal money that use them as host plants for their caterpillars )
Piedmont Virginia Native Plant Database , Albemarle.org ( by plant categories in VA by county or state )
Native Plant Finder , Virginia Department of Conservation and Recreation ( plants native to Virginia agree to 3 regions : Mountains , Piedmont , and Coastal )
“ interaction with Milkweed,”Monarch Joint Venture
“ Which Milkweeds Do Monarchs Prefer?”USDA
“ Harvesting Milkweed Seed : A Pod and a Plan , ” Xerces Society
“ How to pile up Milkweed Seeds ( Without the Fluff),”SaveOurMonarchs Foundation
“ If you plant it , They will come,”University of Florida
“ Milkweed is take over my perennial garden . How can I save some for the Danaus plexippus butterflies but keep it from spreading?”University of New Hampshire Extension
“ Annual Life Cycle,”Monarch Joint Venture
“ Monarch Nectar Plant Guides,”Xerces Society
“ Asclepias incarnata,”NC State Extension
“ Featured fauna : Oleander Aphid,”University of Florida
“ Asclepias purpurascens,”U.S. Forest Service
“ Conservation Assessment for Purple Milkweed(Asclepias Purpurascens),”USDA Forest Service , Eastern Region , 2003
“ Native Plant Nurseries,”Virginia Native Plant Society
Ian Caton , Wood Thrush Native Nursery
“ Butterfly Weed , Asclepias tuberosa,”University of Wisconsin Extension
“ Butterfly Weed ( Asclepias tuberosaL.),”U.S. Forest Service
“ Asclepias verticillata,”NC State Extension
“ Asclepias verticillata,”Lady Bird Johnson Wildflower Center Plant Database
“ Tropical Milkweed – A No - Grow,”Xerces Society
“ Is Tropical Milkweed Killing Monarch Butterflies?”Monarch Butterfly Garden
“ Exposure to Non - Native Tropical Milkweed Promotes Reproductive Development in Migratory Monarch Butterflies,”NIH , National Library of Medicine , National Center for Biotechnology Information
“ Global Warming Can Turn Monarch Butterflies ’ Favorite Food into Poison,”Science Daily , 2025-01-21
Q&A relate to Research About Tropical Milkweed and Monarch Parasites,”Monarch Joint Venture
“ UGA research on milkweed breeding have on the masking of HortScience,”University of Georgia CAES Newswire 2025-04-28
“ A Closer Look at Monarchs and Milkweed . previous data from Xerces,”Kim Eierman , Ecobeneficial , 2014 .
