Table of Contents for Allen County, OH Native or Nearly Native Milkweeds
There are fifteen species of native or nearly native Allen County milkweeds (Asclepias spp.) that can be grown for butterflies and other insects. Milkweeds are an important host species for monarch butterflies in Ohio. The monarch butterfly in particular uses the cardenolides found in the milky sap of milkweeds to give an unpleasant taste to predators. These plants are also an important nectar source to all insects visiting your pollinator garden.
General Information about Native Plant and Pollinator Gardens
When planting a native plant and pollinator garden in Allen County, OH, you need to ensure that you have a selection of plants that provide blooms at different times of the year. In addition to the plants, you need to provide a source of water such as a birdbath or water feature, shelter for animals, and nesting locations for birds. Be sure to also include plants of different heights for perching. Resources you can use for more information on butterfly gardening in Allen County include the Allen County Master Gardeners.
Location of Allen County, Ohio

Allen County is located in northwestern Ohio. Lima is the largest city in the county.
USDA Plant Hardiness Zones in Allen County, Ohio

Allen County is located in two plant hardiness zones. Most of the county is in zone 6a, while a small portion around Lima is in zone 6b. When selecting plants you will want to get those that can handle temperatures as cold as -100F in most of the county except for the area around where it would be -50F.
Butterflies in Allen County, Ohio that are Hosted by Milkweeds (Asclepias spp.)

Monarch Butterfly (Danaus plexippus)
The monarch butterfly is an iconic butterfly in North America and is a bell-weather of the environment. Having a distinctive orange color with black stripes, this butterfly has a wingspan of 3 in (7.6 cm) to 5 in (12.7 cm). The monarch butterfly uses milkweed to get cardenolides, a toxin that is distasteful to predators. This butterfly can have several flights a year and is known for its migrations to Mexico each year. However, some populations in California, Arizona, and Florida do not migrate and breed year-round (Urguhart, et al 1968).
List of Milkweeds that are Native or Nearly Native in the Allen County, OH Area
1. Clasping Milkweed (Asclepias amplexicaulis), a Milkweed for Sandy Soils
Clasping milkweed grows in average garden soil but be sure that the soil has good drainage and does not dry out. This species likes sunny locations and success is often found by planting from seeds. Smaller plants of this species could be candidates for container plants.

Facts about Clasping Milkweed
- Native to Ohio: Yes, rare in the southern and northern counties (Kartesz 2015)
- Native to Allen County: No
- Natural Habitat: dry woodlands, prairies, meadows and roadsides
- Height: up to 3 ft (0.9 m)
- Flower Color: greenish-pink, red, brown, to purple
- Flowering Period: March to September
- USDA Hardiness Zone: 3-9
Gardening with Clasping Milkweed
In your Allen County butterfly garden, clasping milkweed needs full sun to part-shade and moist to dry sandy soils.
2. Poke Milkweed (Asclepias exaltata), a Milkweed for Shade and Moist Soils
In you have shade in your garden this plant is for you. Poke milkweed, a medium to tall milkweed for Ohio, likes moist soil and has beautiful white flowers.

Facts about Poke Milkweed
- Native to Ohio: Yes, common in the eastern counties, scattered in the west (Kartesz 2015)
- Native to Allen County: No
- Natural Habitat: moist woods, roadsides, and edges of woods
- Height: up to 2 ft (0.6 m) to 6 ft (1.8 m)
- Flower Color: white to green with tinges of rose, purple or blue
- Flowering Period: May to August
- USDA Hardiness Zone: 3-9
Gardening with Poke Milkweed
In your Allen County butterfly garden, poke milkweed prefers part shade to full shade and moist soil.
3. Swamp Milkweed (Asclepias incarnata), a Milkweed for Moist Soils
Swamp milkweed is one of the more common milkweeds planted in the eastern half of the United States and is a medium to tall milkweed. Seeds can be started indoors in the winter and then transplanted outdoors. This species likes moist soils, but can exist in medium soils in a garden situation, if the soil is not allowed to dry out. If you have other wetland species in your garden this plant would a be perfect compliment to provide for the monarch butterfly.

Facts about Swamp Milkweed
Asclepias incaranta subsp. incarnata in Ohio
- Native to Ohio: Yes, throughout (Kartesz 2015)
- Native to Allen County: Yes
- Natural Habitat: shores of streams, lakes, ponds, and other wetlands
- Height: 3 ft (0.9 m) to 5 ft (1.5 m)
- Flower Color: white, rose, red, pink to purple
- Flowering Period: July to September
- USDA Hardiness Zone: 3-9
Gardening with Swamp Milkweed
In your Allen County butterfly garden, this milkweed needs full sun or partial shade and moist soil, but can handle medium soil in a garden. This species also has a white cultivar called ‘Ice Ballet’.
4. Long-leaf Milkweed (Asclepias longifolia), a Milkweed for Moist Soils
If you need a shorter milkweed to compliment swamp milkweed in a moist garden, this species would be a good choice. While not native on Allen County, it can handle the plant hardiness zone and can exist long-term in light of climate induced warming.

Facts about Long-leaf Milkweed
- Native to Ohio: Yes, southern and northern counties (Kartesz 2015)
- Native to Allen County: No
- Natural Habitat: moist areas and wetlands such as bogs, swamps, wet flatwoods, and moist prairies
- Height: 1 ft (0.3 m) to 2.5 ft (0.8 m)
- Flower Color: greenish-white with a purple tinge
- Flowering Period: April to July
- USDA Hardiness Zone: 4-10
Gardening with Long-leaf Milkweed
In your Allen County butterfly garden, this milkweed needs full sun and moist to wet soils.
5. Purple Milkweed (Asclepias purpurascens), a Milkweed for Moist Well-drained Soils
Purple milkweed is native to Allen County and is another plant for moist soils, but are well-drained. Like some of the others, you can start the seeds indoors during the winter and then transplant the seedlings in the spring. Besides the moist soil, this likes part-shade, but can tolerate full sun.

Facts about Purple Milkweed
- Native to Ohio: Yes, generally throughout but scattered (Kartesz 2015)
- Native to Allen County: Yes
- Natural Habitat: swamps, woodlands, meadows, and roadsides
- Height: up to 6 ft (1.8 m)
- Flower Color: purple, rose to pink (they can mature to purple)
- Flowering Period: May to July
- USDA Hardiness Zone: 3-8
Gardening with Purple Milkweed
In your Allen County butterfly garden, this milkweed needs full sun to part-shade and moist well-drained soils.
6. Four-leaf Milkweed (Asclepias quadrifolia), a Milkweed for Dry Rocky Soils
If have a loam, sand, or clay that is on the dry side of average, this may be the milkweed for you. Along with the soils four-leaf milkweed enjoys basking in full sun and also like the others it can be started by seed in the winter and then transplanted in the spring.

Facts about Four-leaf Milkweed
- Native to Ohio: Yes, throughout except the northwest (Kartesz 2015)
- Native to Allen County: No
- Natural Habitat: roadsides, pastures, and prairies with disturbance
- Height: 1 ft (0.3 m) to 2 ft (0.6 m)
- Flower Color: white to pink
- Flowering Period: April to July
- USDA Hardiness Zone: 5-8
Gardening with Four-leaf Milkweed
In your Allen County butterfly garden, this milkweed needs full sun to part-shade and dry rocky soils.
7. Aquatic Milkweed (Asclepias perennis), a Milkweed for Moist Soils
In you have an area in your garden that is very wet in Allen County, aquatic milkweed could be your milkweed choice. A species from more southern areas, it can now handle the plant hardiness zone in the Lima, OH area. This plant can help those butterflies from the south find a host and nectar plant they are familiar with as they move north with climate change.

Facts about Aquatic Milkweed
- Native to Ohio: No, not present (Kartesz 2015)
- Native to Allen County: No
- Natural Habitat: margins of wetlands such as swamps, alluvial woods, ditches, and marshes
- Height: 1 ft (0.3 m) to 3.5 ft (1.1 m)
- Flower Color: white, pink, purplish-rose, or purple
- Flowering Period: April to October
- USDA Hardiness Zone: 6-10
Gardening with Aquatic Milkweed
In your Allen County butterfly garden, this milkweed needs full sun to partial-shade and moist soil.
8. Showy Milkweed (Asclepias speciosa), a Milkweed for Medium to Well-drained Soils
Showy milkweed is a common plant in butterfly gardens around the United States. It is a short to medium tall milkweed, making it suitable for containers, but whether planted or in a container, it needs good drainage.

Facts about Showy Milkweed
- Native to Ohio: No, adventive in one county in north (Kartesz 2015)
- Native to Allen County: No
- Natural Habitat: roadsides, fields and woodlands
- Height: 1 ft (0.3 m) to 3 ft (0.9 m)
- Flower Color: purple to pink
- Flowering Period: April to June
- USDA Hardiness Zone: 3-9
Gardening with Showy Milkweed
In your Allen County butterfly garden, this milkweed needs full sun and medium to well-drained soil.
9. Sullivant’s Milkweed (Asclepias sullivantii), a Milkweed for Medium to Dry Soils
Sullivant’s milkweed has deep roots that are adapted for living on the prairie, giving its alternative name of Prairie Milkweed. Soils for this plant should be medium to somewhat dry and well-drained, but it can handle some wetness. The soils should also be relatively undisturbed. Like a number of other milkweeds, seeds can be started in the winter.

Facts about Sullivant’s Milkweed
- Native to Ohio: Yes, central and northwestern counties (Kartesz 2015)
- Native to Allen County: No
- Natural Habitat: prairies, meadows, roadsides, and railroads
- Height: 2 ft (0.6 m) to 5 ft (1.5 m)
- Flower Color: purple to pink
- Flowering Period: June to July
- USDA Hardiness Zone: 3-7
Gardening with Sullivant’s Milkweed
In your Allen County butterfly garden, this milkweed needs full sun and medium to dry sandy soil.
10. Common Weed (Asclepias syriaca), a Milkweed for all Conditions
Common milkweed is a medium large milkweed that can pretty much grow in any condition with sun. In a garden, it needs space to spread out since it has rhizomes. Oftentimes it will appear in other places where it was originally not planted.

Facts about Common Milkweed
- Native to Ohio: Yes, throughout (Kartesz 2015)
- Native to Allen County: Yes
- Natural Habitat: fields, pastures, and roadsides
- Height: up to 6 ft (1.8 m)
- Flower Color: pink, greenish-purple, greenish-white to white
- Flowering Period: June to August
- USDA Hardiness Zone: 3-9
Gardening with Common Milkweed
In your Allen County butterfly garden, this milkweed needs full sun to part-shade and soils that are well-drained and occasionally dry.
11. Butterfly Weed (Asclepias tuberosa), a Milkweed for all Conditions
Butterfly weed is one of three milkweeds in the United States that has an orange colored flower and is often used in butterfly gardens. It is also one of two milkweeds that does have milky sap. When planting this species it is important to not over water it.

Facts about Butterfly Weed
- Native to Ohio: Yes, throughout (Kartesz 2015)
- Native to Allen County: Yes
- Natural Habitat: fields, roadsides, and open woods
- Height: 1 ft (0.3 m) to 3 ft (0.9 m)
- Flower Color: orange
- Flowering Period: June to October
- USDA Hardiness Zone: 3-9
Gardening with Butterfly Weed
In your Allen County butterfly garden, this milkweed needs full sun and nearly any soil type.
12. Red-ring Milkweed (Asclepias variegata), a Milkweed for Medium to Dry Sandy Soils
This milkweed thrives in average garden soils, but can handle dry or moist soil, if needed. Just do not let the soil dry out. This plant is best started in the winter as seed and then planted in the spring in part-sun to light-shade.

Facts about Red-ring Milkweed
- Native to Ohio: Yes, rare in southern counties and one county in northeast (Kartesz 2015)
- Native to Allen County: No
- Natural Habitat: open disturbed areas such as thickets and roadsides
- Height: 1 ft (0.3 m) to 3 ft (0.9 m)
- Flower Color: white with a ring of red or purple at base
- Flowering Period: May to July
- USDA Hardiness Zone: 3-9
Gardening with Red-ring Milkweed
In your Allen County butterfly garden, this milkweed needs part-sun to light-shade and dry sandy or rocky soils.
13. Whorled Milkweed (Asclepias verticillata), a Milkweed for Medium to Dry Soils
Whorled milkweed has a small stature and is best planted on edges where it can get the most sun. With its thin leaves it can add an interesting texture to the garden. Smaller individuals may possibly be planted in containers.

Facts about Whorled Milkweed
- Native to Ohio: Yes, central and northwestern counties (Kartesz 2015)
- Native to Allen County: No
- Natural Habitat: meadows and fields
- Height: 1 ft (0.3 m) to 3 ft (0.9 m)
- Flower Color: green to white
- Flowering Period: May to September
- USDA Hardiness Zone: 3-9
Gardening with Whorled Milkweed
In your Allen County butterfly garden, this milkweed needs full sun to part shade and medium to dry soil.
14. Green Comet Milkweed (Asclepias viridiflora), a Milkweed for Medium to Dry Soils
Green comet milkweed is a small to medium sized milkweed with a large taproot that can handle drier soils. Having an earlier flowering time than most milkweeds it is one of the first milkweeds to die back in the fall in Ohio.

Facts about Green Comet Milkweed
- Native to Ohio: Yes, central and eastern counties (Kartesz 2015)
- Native to Allen County: No
- Natural Habitat: meadows and fields
- Height: 1 ft (0.3 m)to 3 ft (0.9 m)
- Flower Color: green when young, becoming yellow-green to purple-green with age
- Flowering Period: July to August
- USDA Hardiness Zone: 3-9
Gardening with Green Comet Milkweed
In your Allen County butterfly garden, this milkweed needs full sun to part shade and medium to dry sandy soil.
15. Green Milkweed (Asclepias viridis), a Milkweed for Medium to Dry Soils that have a high pH
Green milkweed is a small milkweed with a large taproot allowing it to handle dry soils. It needs to planted in full sun and whichever soil it is in should be well-drained..

Facts about Green Milkweed
- Native to Ohio: Yes, south-central counties (Kartesz 2015)
- Native to Allen County: No
- Natural Habitat: prairies, dry hillsides, roadsides (Allison 1995, Lathrop 1958, Whisenant 1981), pasture (Nelson and Harsley 2010), pine barrens (Dee and Palmer 2017), calcareous areas (Weakley 2022).
- Height: 0.5 ft (0.2 m)to 2 ft (0.6 m)
- Flower Color: green (Woodson 1954), yellowish-green (Weakley 2022), or white
- Flowering Period: April to October
- USDA Hardiness Zone: 5-9
Gardening with Green Milkweed
In your Allen County butterfly garden, this milkweed needs full sun and medium to dry soils that are high in pH.
When selecting your Allen County, OH milkweed, be sure to make sure that it grows in your zone and habitat.
Books where you can find out more about Monarchs and Butterfly Gardening in Allen County, OH
- Adelman, Charlotte, and Bernard L. Schwartz. 2017. Midwestern Native Shrubs and Trees – Gardening Alternatives to Nonnative Species. Ohio University Press. 464 pp.
- Branhagen, Alan. 2020. The Midwest Native Plant Primer – 225 Plants for an Earth-Friendly Garden. Timber Press. 256 pp.
- Daniels, Jaret C. 2024. Native Plant Gardening for Birds, Bees & Butterflies: Lower Midwest – Nature-Friendly Gardens. Adventure Publications. 280 pp. (will be published in June 2024)
- Daniels, Jaret C. 2023. Butterflies of the Midwest Field Guide – Butterfly Identification Guides. Adventure Publications. 364 pp.
- Daniels, Jaret C. 2022. Garden Bugs & Insects of the Midwest – Identify Pollinators, Pests, and Other Garden Visitors – Adventure Quick Guides. Adventure Publications. 36 pp.
- Kavanagh, James and Raymond Leung. 2020. Ohio Butterflies & Pollinators – A Folding Pocket Guide to Familiar Species – Wildlife and Nature Identification. Waterford Press. 12 pp.
- Kline, Christopher. 2020. If You Plant It They Will Come – A Butterfly Habitat Creation Success Story. Butterfly Ridge Butterfly Conservation Center. 134 pp.
- McCormac, Jim ad Chelsea Gottfried. 2023. Gardening for Moths – A Regional Guide. Ohio University Press. 472 pp.
- Nowak, Mariette. 2012. Birdscaping in the Midwest – A Guide to Gardening With Native Plants to Attract Birds. University of Wisconsin Press. 336 pp.
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References for Allen County, OH Milkweeds
- Allison, James R. 1995. Prairies…in Georgia! They’re for real, as the flora shows. Tipularia 10: 2-8.
- Dee, Justin R. and Michael W. Palmer. 2017. Annual rings of perennial forbs and mature oaks shows similar effects of climate but inconsistent responses to fore in the Noth American prairie-forest ecotone. Canadian Journal of Forest Research 47: 716-726.
- Kartesz, J.T. The Biota of North America Program (BONAP). 2015. Taxonomic Data Center. Link to website. Chapel Hill, N.C. [maps generated from Kartesz, J.T. 2015. Floristic Synthesis of North America, Version 1.0. Biota of North America Program (BONAP). (in press)]
- Lathrop, Earl W. 1958. The Flora and Ecology of the Chatauqua Hills in Kansas. The University of Kansas Science Bulletin 39(4): 97-210.
- Nelson, A.D. and S. Harsley. 2010. County Records and Major Range Extensions for West Cross Timbers’ Angiosperms from Tarleton State University’s Hunewell Ranch in Erath County, Texas. Texas Journal of Science 62(2): 111-126.
- Urguhart, Fredrick Albert, Norah Roden Urguhart, and Francis Munger. 1968. Population of Danaus plexippus in Southern California. Journal of Research on the Lepidoptera 7(4): 169-181.
- Weakley, A.S. and the Southeastern Flora Team. 2022. Flora of the Southeastern United States. University of North Carolina Herbarium , North Carolina Botanical Garden.
- Whisenant, S.G. 1981. The Vascular Flora of McCullough County, Texas. Texas Journal of Science 33(2,3,4): 197-220.
- Woodson, Robert E. 1954. The North American Species of Asclepias L. Annals of the Missouri Botanical Garden 41: 1-211.