A monarch butterfly (Danaus plexippus) feeding on butterfly weed (Asclepias tuberosa). Monarch populations have been declining in abundance due to loss of habitat in the United States and deforestation at overwintering grounds in Mexico.[1]
Butterfly gardening is a way to create, improve, and maintain habitat for lepidopterans including butterflies, skippers, and moths.[2] Butterflies have four distinct life stages—egg, larva, chrysalis, and adult. In order to support and sustain butterfly populations, an ideal butterfly garden contains habitat for each life stage.
As adults, butterflies feed mainly on nectar, but they have also evolved to consume rotting fruit, tree sap, and even carrion.[6] Supporting nectarivorous adult butterflies involves planting nectar plants of different heights, color, and bloom times. Butterfly bait stations can easily be made to provide a food source for species that prefer fruit and sap. In addition to food sources, windbreaks in the form of trees and shrubs shelter butterflies and can provide larval food and overwintering grounds.[7] "Puddling" is a behavior generally done by male butterflies in which they gather to drink nutrients and water and incorporating a puddling ground for butterflies will enhance a butterfly garden.[8][9] While butterflies are not the only pollinators, creating butterfly habitat also creates habitat for bees, beetles, flies, and other pollinators.[7]
Butterfly gardening provides a recreational activity to view butterflies interacting with the environment. Besides anthropocentric values of butterfly gardening, creating habitat reduces the impacts of habitat fragmentation and degradation. Habitat degradation is a multivariate issue; development, increased use of pesticides and herbicides, woody encroachment, and non-native plants are contributing factors to the decline in butterfly and pollinator habitat.[10] Pollination is one ecological service butterflies provide; about 90% of flowering plants and 35% of crops rely on animal pollination.[10][11] Butterfly gardens and monarch waystations, even in developed urban areas, provide habitat[12] that increases the diversity of butterflies and other pollinators, including bees, flies, and beetles.[13]
Before buying plants and digging into the soil, "ground-truthing" is a necessary first step, Ground-truthing involves surveying a property in order to assess the current resources available. Some aspects to keep in mind are the following:
south-facing slopes
natural wind breaks
present plant species
present butterfly species
Butterflies are ectothermic and rely on solar radiation for their metabolism. South-facing slopes are an ideal location for a butterfly garden, as they provide the most solar radiation (in the Northern Hemisphere; the opposite is true in the Southern Hemisphere). Where native, shrubs and trees such as spicebush (Lindera benzoin), pawpaw (Asimina triloba), sassafras (Sassafras albidum), and black cherry (Prunus serotina), provide windbreaks for butterflies and can also be their host plants.[14][15]
Plants
A coral hairstreak (Satyrium titus) resting on a clump of grass. The larvae will feed upon species in the family Rosaceae, including cherry (Prunus serotina)[15]
The types of plants used in a butterfly garden will determine the species of butterflies that will visit the garden. Lepidoptera societies and the PLANTS Database of the United States Department of Agriculture's (USDA's) Natural Resources Conservation Service provide state and county-level distribution maps of specific plants.[16] Published lists of host plants for butterflies and other pollinators can help select the plant species desired in the garden.[17]
While non-native plants can provide floral resources to a garden, they can also have an overall negative effect on butterflies and other pollinators.[10] Therefore, it is often recommended to use native plants. It is also important to check invasive species lists to ensure that plants are not invasive in a given locality or region. The Invasive Plant Atlas of the United States and similar publications can help provide such information.[18]
The eastern monarch migration largely depends upon only three milkweed species: common milkweed (Asclepias syriaca), green antelope horn milkweed (A. viridis), and antelope horns milkweed (A. asperula).[22] Butterfly gardens and monarch waystations in eastern and central North America should therefore feature one or more of those species, depending upon the areas in which the species are native.
Spicebush (Lindera benzoin), a shrub that is native to the eastern half of the United States, has white, yellow, and green flowers that also provide nectar to pollinators during the spring. L. benzoin hosts the caterpillars of the spicebush swallowtail and eastern tiger swallowtail butterflies and the promethea silkmoth.[25]
Avoid cultivars of plants unless they are more resistant to diseases than their native parents or that investigations have proven to be more beneficial to pollinators than their parents. Many cultivars are sterile and produce no nectar or pollen. As a result, their flowers do not benefit butterflies and other pollinators. Some have "double flowers". Their reproductive parts have been converted into extra petals and therefore do not produce floral rewards for pollinators. Some cultivars have reduced nutritional benefits, and have not been studied enough to identify those that may be harming pollinators.[26]
Cultivars with features that significantly affect flower structure and/or color are those that are likely to alter their appeal to pollinators. Those selected for foliage color may be toxic to insects. Studies have shown that altering leaf color, and the chemical changes that this implies, reduces a plant’s ability to serve as a resource for herbivorous insects.[27]
Buddleja davidii, which is often called "butterfly-bush", attracts many butterflies.[28] As it originated in China, it is presently planted in many parts of the world in which it is non-native.[28] In such settings, the plant feeds many native butterflies and other adult pollinators, but not many of their larvae.[29] As B. davidii is invasive in some areas, plantings of the species are controversial.[29][30] To prevent seeding and to promote further flowering, its blossoms need to be removed ("deadheaded") as soon as they are spent.[28]
A number of Buddleja cultivars have become available that have a variety of sizes and blossom colors. University studies have suggested that nectaring butterflies have greater preferences for some of these than for others, with Lo & Behold 'Blue Chip' and 'Pink Delight' heading a list of eleven.[31]
Some Buddleja cultivars are either sterile or produce less than 2% viable seed (see "Non-invasive" Buddleja cultivars).[28][29][32][33] The state of Oregon, which designates B. davidii as a "noxious weed" and initially prohibited entry, transport, purchase, sale or propagation of all of its varieties, amended its quarantine in 2009 to permit those cultivars when approved or when proven to be interspecific hybrids.[28][29][32][34]Monarch Watch recommends planting only male-sterile "Flutterby" cultivars.[35]
It is important to avoid purchasing plants and seeds treated with insecticides such as neonicotinoids. Although not yet conclusive, there is increasing evidence that neonicotinoids can have negative effects on pollinating insects, including butterflies.[36]
"Puddling" refers to the behavior of male butterflies congregating on wet soil, dung, and carrion to feed on nutrients, specifically sodium.[8] Nectar is low in sodium, and sodium is a limiting nutrient for Lepidoptera. Male butterflies are able to transfer sodium to females during copulation. The sodium is passed onto offspring and increases reproductive success.[9] To create a simple puddling habitat, fill a shallow dish (like a draining tray for a pot) with wet sand. To increase the nutrients, mix compost with the sand. Add footholds for butterflies by adding different sized rocks.
Baiting
There are numerous recipes for creating butterfly bait, but they have common ingredients. Fermentation is the key to a good bait, as it mimics the fermentation of rotting fruit and sap in the natural environment.[37] Recipes include blending rotten fruit (i.e. bananas) with beer, maple syrup, molasses, or sugar. Often yeast is added as well to the mixture and left to ferment for a week. Urine is also known to attract fruit-feeding butterflies.[38] The bait can be laid on stumps, rocks, and tree limbs.
In the absence of pesticides, aphids and true bugs may infest plants. Some gardeners release ladybugs (ladybirds) and other biological pest control agents that do not harm butterflies in order to control aphids. However, the release of ladybugs is not desirable in the United States and in many other locations, where the invasive Chinese ladybug (Harmonia axyridis) is often the species released. Perhaps more importantly, ladybugs and other predatory or parasitic insects can prey on butterfly and moth caterpillars and pupae even if they do not do so on adult Lepidoptera.
As an alternative, one can wait for local predatory insects to find the aphids. One can hasten this process if an infestation is high by spraying the plants with a mix of sugar and water, simulating aphid honeydew. This is known to attract lacewings whose larvae eat aphids.[39]
One can also spray the plants with water, or rinse the plants with a mild detergent/water solution (although caterpillars should be relocated before suds are applied). Scented detergents are acceptable; those containing OxiClean should be avoided. The aphids will turn black within a day, and eventually fall off. Another technique is to plant a variety of different flowers, including ones that attract hoverflies and parasitic braconid wasps (Braconidae), whose larvae kill pest species. Further, some caterpillars such as those of the harvester butterfly (Feniseca tarquinius) feed on certain species of aphids, but not on plants.[40]
Caterpillars can exhaust their source of food in small home gardens before metamorphosis occurs. Installing multiple plants can help reduce the chance of running out of leaves. If raising monarchs, one can replace the expended milkweed with a slice of pumpkin or cucumber, which can serve as a substitute source of food for monarch caterpillars in their final (fifth) instar.[41]
Plantings of tropical milkweed/bloodflower (A. curassavica) are problematic. Where planted or naturalized in the southern United States, the non-native A. curassavica hosts monarch reproduction throughout the winter. This may alter the butterflies' migratory and breeding instincts, thus causing them to avoid migration and subsequent breeding and to increase their risk of infection.[42]
Monarch Watch provides information on rearing monarchs and their host plants.[43] Efforts to restore falling butterfly populations by establishing butterfly gardens and migrating monarch "waystations" require particular attention to the target species' food preferences and population cycles, as well to the conditions needed to propagate and maintain their food plants.[44]
Awareness of different milkweed species is of vital importance. For example, in the Washington, D.C., area and elsewhere in the northeastern and midwestern United States, common milkweed (Asclepias syriaca) is among the most important food plants for monarch caterpillars,[45] especially when its foliage is soft and fresh. As monarch reproduction in that area peaks in late summer, when most A. syriaca leaves are old and tough, the plant needs to be cut back in June, July, or August, to assure that it will be regrowing rapidly, when monarch reproduction reaches its peak. Similar conditions exist for showy milkweed (A. speciosa) in Michigan and for green antelopehorn milkweed (A. viridis) where it grows in the southern Great Plains and the western United States.[46] In addition, the seeds of A. syriaca and some other milkweeds need periods of cold treatment (cold stratification) before they will germinate.[47]
To protect seeds from washing away during heavy rains and from seed-eating birds, one can cover the seeds with a light fabric or with an 0.5 in (13 mm) layer of straw mulch.[48] However, mulch acts as an insulator. Thicker layers of mulch can prevent seeds from germinating if they prevent soil temperatures from rising enough when winter ends. Further, few seedlings can push through a thick layer of mulch.[49]
Many species of milkweed contain toxic cardiac glycosides (cardenolides). Monarch caterpillars deter predators by incorporating these chemical compounds into their bodies, where the toxins remain throughout the insect's lifetime.[50] Although monarch caterpillars will feed on butterfly weed (A. tuberosa) in butterfly gardens, it is typically not a heavily used host plant for the species.[51] The plant contains only low levels of cardiac glycosides. This may make A. tuberosa unattractive to egg-laying monarchs.[52] Some other milkweeds have similar characteristics.[53]
A. tuberosa also has rough leaves and a layer of trichomes, which may inhibit oviposition or decrease a female's ability to sense leaf chemicals.[54][55] As a result of these factors, reproducing monarchs lay fewer eggs on A. tuberosa than they do on most other milkweeds.[54][51] While the plant's colorful flowers provide nectar for many adult butterflies, A. tuberosa may therefore be less suitable for use in butterfly gardens and monarch waystations than are other milkweed species.[54]
Breeding monarchs prefer to lay eggs on swamp milkweed (A. incarnata).[56]A. incarnata is therefore often planted in butterfly gardens and monarch waystations to help sustain the butterfly's populations.[57][58]
However, A. incarnata is an early successional plant that usually grows at the margins of wetlands and in seasonally flooded areas. The plant is slow to spread via seeds, does not spread by runners and tends to disappear as vegetative densities increase and habitats dry out.[59] Although A. incarnata plants can survive for up to 20 years, most live only two-five years in gardens. The species is not shade-tolerant and is not a good vegetative competitor.[59]
Butterflies and moths at typical nectar-foodplants
^Brower, Lincoln P.; Taylor, Orley R.; Williams, Ernest H.; Slayback, Daniel A.; Zubieta, Raul R.; Ramírez, M. Isabel (March 2012). "Decline of monarch butterflies overwintering in Mexico: is the migratory phenomenon at risk?: Decline of monarch butterflies in Mexico". Insect Conservation and Diversity. 5 (2): 95–100. doi:10.1111/j.1752-4598.2011.00142.x. hdl:2060/20140010155. S2CID86566051.
^Ômura, Hisashi; Honda, Keiichi (November 2003). "Feeding responses of adult butterflies, Nymphalis xanthomelas, Kaniska canace and Vanessa indica, to components in tree sap and rotting fruits: synergistic effects of ethanol and acetic acid on sugar responsiveness". Journal of Insect Physiology. 49 (11): 1031–1038. Bibcode:2003JInsP..49.1031O. doi:10.1016/j.jinsphys.2003.07.001. PMID14568581.
Lotts, Kelly; Naberhaus, Thomas (2017). "Imperial moth Eacles imperialis (Drury, 1773)". Butterflies and Moths of North America. Metalmark Web and Data. Archived from the original on February 19, 2024. Retrieved October 15, 2024.
Carlton, Marc; Bostock, Helen. Head, Steve (ed.). "Plants for Pollinators". United Kingdom: Wildlife Gardening Forum. Archived from the original on July 30, 2021. Retrieved August 1, 2021. 'Double' or flora pleno flowers have been bred so that most, or all, of the reproductive parts of the flower have been converted into extra petals, so are useless for pollinators.
Vazquez, Claudio (2021). "Cultivars...Don't shoot the messenger!". Washington, D.C.: Izel Native Plants. Archived from the original on June 15, 2024. Retrieved October 14, 2024. The rule of thumb is that cultivars that significantly affect flower structure and/or color are the ones likely to alter their appeal to pollinators. ….. There is a strong indication that altering leaf color, and the chemical changes this implies, reduces a plant's ability to serve as a resource for herbivorous insects.
Dhuill, E.N.; Smyth, N. (2021). "Invasive non-native and alien garden escape plant species on the southern cliffs of Howth, Co. Dublin (H21)". Irish Naturalists' Journal. 37 (2): 102–108.
"Neonicinoid Pesticides — The Facts". Neonicotinoid Pesticides & Bee Colonies. Compound Interest: Explorations of everyday chemical compounds. April 2015. Archived from the original on August 2, 2021. Retrieved August 2, 2021. Can accumulate in soil; low concentrations found in nectar of treated crops. .... Negative impacts on monarch butterly populations in the USA have recently been suggested.
National Academies of Sciences, Engineering, and Medicine (2020). Evaluating the Suitability of Roadway Corridors for Use by Monarch Butterflies. Washington, D.C.: National Academies Press. pp. 79–80. doi:10.17226/25693. ISBN9780309481328. LCCN2020935714. OCLC1229163481. S2CID218854539. National Cooperative Highway Research Program (NCHRP) Research Report 942. Archived from the original on July 29, 2020. Retrieved July 8, 2021. Could roadside mowing stimulate milkweed growth and support monarch breeding? Limited research in eastern North America has shown that spring or summer mowing can promote new growth and extend the availability of milkweed plants for monarch breeding. Mowing may stimulate growth of some milkweed species, particularly those that spread through rhizomes like common milkweed (A. syriaca) and showy milkweed (A. speciosa). Summer (June or July) mowing in Michigan resulted in more monarch eggs on regenerated stems than unmowed stems. Summer (July) mowing and burning can increase green antelopehorn milkweed (A. viridis) availability in the late summer and early fall in the Southern Great Plains, whereas in areas without mowing, the milkweed has senesced by August. In the West, showy milkweed will regrow after summer mowing and continue to support monarch breeding (Stephanie McKnight, personal observation). However, more research is needed in other areas to determine the optimal timing and frequency of mowing that promotes not only milkweed but also nectar plants. It is also unknown if the benefit of additional milkweed availability in the fall outweighs the costs of the larval mortality caused by summer mowing. The benefits are likely greater in areas that primarily have breeding monarchs in the spring and fall and where the dominant species of milkweed spread by rhizomes. Sources: Alcock et al. 2016; Baum and Mueller, 2015; Bhowick 1994; Haan and Landis 2019; Fischer et al. 2015{{cite book}}: CS1 maint: multiple names: authors list (link)
Higgins, Adrian (May 27, 2015). "A gardener's guide to saving the monarch". Home & Garden. The Washington Post. Archived from the original on May 31, 2015. Retrieved October 17, 2020. 'The monarch doesn't care where the milkweed grows, and putting it in residential neighborhoods makes perfect sense,' said Doug Tallamy, an entomologist at the University of Delaware, author and expert on wildlife habitat gardens. .... The Smithsonian Institution's Butterfly Habitat Garden .... and the Ripley Garden .... are both good places to see milkweed integrated into a garden setting. At the butterfly garden, you can see the common milkweed ... now looking pretty good in fresh, unblemished clumps. By late summer, it looks tall, tired and tough. Tallamy says if you grow it, you should cut it back at least by half in June to produce soft foliage in late summer that will be more munchable for the caterpillars. If you do that, make sure there are no larvae on the plant before you chop it.
Abugattas, Alonzo (January 3, 2017). "Monarch Way Stations". Capital Naturalist. Archived from the original on March 8, 2021. Retrieved July 5, 2021 – via Blogger. Virginia is blessed for instance with 13 native Asclepias species plus 4 climbing vines that Monarch caterpillars can feed on. For the best results, cut the some of the stems back in late summer after they've bloomed. Fall is the when we get the most Monarchs laying eggs on our milkweeds. Since the mother butterflies prefer young, more tender growth, you can provide this by timing your pruning so there are new leaves by September or so for the arriving Monarchs. Just make sure to leave a few to produce pods for seeds. The local monarch favorite is Common Milkweed (A. syriaca), .....
Gomez, Tony. "Asclepias syriaca: Common Milkweed for Monarch Caterpillars". Monarch Butterfly Garden. MonarchButterflyGarden.net. Archived from the original on March 16, 2015. Retrieved October 17, 2010. Cut- At mid season after the blooms have faded, cut some common plants back by about a third. This promotes fresh plant growth and could get you an extra generation of monarchs on the fresh new leaves. Leave some plants uncut if you want to harvest milkweed seeds in fall.
Landis, Thomas D.; Dumroese, R. Kasten (2015). "Propagating Native Milkweeds for Restoring Monarch Butterfly Habitat"(PDF). International Plant Propagators' Society, Combined Proceedings (2014). 64: 302. Archived(PDF) from the original on March 8, 2021. Retrieved July 11, 2021 – via United States Department of Agriculture: United States Forest Service. Many sources of milkweed seeds require stratification (cold, moist treatment) before sowing. In a review of stratification requirements for common milkweed, recommendations varied from as short as 7 days to as long as 11 months at 5°C (41°F) (Luna and Dumroese, 2013). Butterfly milkweed (A. tuberosa) germination increased from 29 to 48 to 62% as stratification duration increased from 0 to 30 to 60 days, respectively (Bir, 1986). Our informal natural stratification trial with showy (milkweed) and narrow leaf milkweed (A. fascicularis) in southern Oregon revealed that seeds began to germinate after 15 weeks in stratification (Fig. 3A).
Higgins, Adrian (May 27, 2015). "7 milkweed varieties and where to find them". Home & Garden. The Washington Post. Archived from the original on September 26, 2020. Retrieved October 17, 2020. Seed may be stubborn to germinate and may need a period of cold treatment.
Gomez, Tony. "Asclepias syriaca: Common Milkweed for Monarch Caterpillars". Monarch Butterfly Garden. MonarchButterflyGarden.net. Archived from the original on March 16, 2015. Retrieved October 17, 2010. Start seeds indoors 2 months before final frost- seeds must be cold stratified.
"Asclepias syriaca". Butterfly gardening & all things milkweed. Archived from the original on July 7, 2015. Retrieved July 7, 2015. germination: seed requires cold moist period.
Landis, Thomas D.; Dumroese, R. Kasten (2015). "Propagating Native Milkweeds for Restoring Monarch Butterfly Habitat: Propagating Native Milkweeds: Seed Propagation"(PDF). International Plant Propagators' Society, Combined Proceedings (2014). 64: 302. Archived(PDF) from the original on March 8, 2021. Retrieved July 11, 2021 – via United States Department of Agriculture: United States Forest Service. Any of the standard seed propagation methods (Landis et al., 1999) are effective with milkweed. Direct sowing of non-stratified seeds during the fall followed by exposure to ambient winter conditions can be effective, but the seeds must be mulched and protected. Cover sown seeds with a thin mulch; research has found that common milkweed seeds germinated better when planted 1 to 2 cm (0.4 to 0.8 in.) deep than when at the soil surface (Jeffery and Robison, 1971).
^ abButterfly Society of Virginia (2019). "Growing Milkweed". Archived from the original on June 24, 2019. Retrieved December 25, 2023. I've grown butterfly weed, swamp milkweed, Asclepias currassavica (bloodflower), Asclepias syriaca (common milkweed), and Asclepias verticillata (whorled milkweed). I've found that butterfly weed is the least favorite of my Monarch guests in my Virginia Beach garden for laying eggs (perhaps the leaves are tougher?)
Gunn, John (May 20, 2016). "Milkweeds (mostly Asclepias spp.)". Alonso Abugattas Shares Native Plant Picks for Wildlife. Mid-Atlantic Gardener (John Gunn). Archived from the original on October 21, 2020. Retrieved October 17, 2020. And if you have hot, dry conditions in your yard, try Butterflyweed (A. tuberosa). .... It's the least favored by Monarch caterpillars because it has very little toxin (cardiac glycosides) in its leaves.
Abugattas, Alonzo (January 3, 2017). "Monarch Way Stations". Capital Naturalist. Archived from the original on June 5, 2017. Retrieved June 5, 2017 – via Blogger. (A. tuberosa) is the least favored by monarch caterpillars .... because it has very little toxin (cardiac glycosides) in its leaves, .... .
"Butterfly Weed: Asclepias tuberosa"(PDF). Becker County, Minnesota: Becker Soil and Water Conservation District. Archived(PDF) from the original on September 11, 2020. Retrieved September 11, 2020. Unlike other milkweeds, this plant has a clear sap, and the level of toxic cardiac glycosides is consistently low (although other toxic compounds may be present).
^Abugattas, Alonzo (January 3, 2017). "Monarch Way Stations". Capital Naturalist. Archived from the original on March 8, 2021. Retrieved July 5, 2021 – via Blogger. A better option for most gardeners might be Swamp Milkweed (A. incarnata) which, despite its name, does fine in regular garden soil and doesn't spread by runners.
^ ab"Asclepias incarnata". Bring Back The Monarchs. Monarch Watch. Archived from the original on June 12, 2021. Retrieved July 5, 2021. Life span: In gardens most plants live two-five years but known to survive up to 20 years. .... Propagation: Slow to spread via seeds. .... 'Overhead Conditions: Not shade tolerant. An early successional plant that tends to grow at the margins of wetlands and in seasonally flooded areas. It is not a good vegetative competitor and tends to disappear as vegetative density increases and habitats dry out.
.jpg)
.jpg)
.jpg)
_(3870886368).jpg)
_white_lined_sphinx_moth_on_showy_milkweed_Seedskadee_National_Wildlife_Refuge_02_(14784615191).jpg)
.jpg)
.jpg)
.jpg)
.jpg)
.jpg)
