Iris virginica var. shrevei (Southern Blue Flag)
Iris virginica var. shrevei (Southern Blue Flag)
Couldn't load pickup availability
$30 minimum per species for seed.
$30 minimum per species for seed.
Each species requires a minimum of $30 of seed to proceed with checkout.
Pure Live Seed
Pure Live Seed
Seed is provided in Pure Live Seed (PLS) unless otherwise stated.
Pure Live Seed (PLS) refers to the percentage of a seed lot that consists of the desired species and is viable (capable of germination).
Here's why PLS is crucial for native seeds:
-
Accurate Planting:
- PLS helps determine the actual number of viable seeds in a given weight or volume of seed.
- This ensures you plant the correct amount of seed to achieve the desired density and success rate.
-
Cost-Effectiveness:
- By knowing the PLS, you can avoid overspending on seed that may not germinate.
- This is especially important for native seeds, which can be more expensive than some cultivated varieties.
-
Weed Control:
- PLS helps minimize the presence of weed seeds within the seed lot.
- This reduces competition for resources and ensures the successful establishment of the desired native plants.
-
Ecological Restoration:
- Using high-quality native seeds with a high PLS is essential for successful ecological restoration projects.
- It helps to re-establish diverse and resilient plant communities that support local wildlife.
Weight Conversions lbs. to oz.
Weight Conversions lbs. to oz.
0.01 pounds = 0.16 ounces
- 0.1 pounds = 1.6 ounces
- 0.25 pounds = 4 ounces
- 0.5 pounds = 8 ounces
- 0.75 pounds = 12 ounces
- 1.00 pounds = 16 ounces
Shreve's iris forms clumps of long, sword-shaped leaves in moist or wet ground. Too much shade can suppress flowers, and drying soil can reduce the planting over time.
For Iris virginica var. shrevei, choose full to partial sun and wet to moist soil. Recorded habitats include wet to moist black-soil prairies; Prairie swales; Soggy riverside meadows; Open bottomland woods; Swamps; Fens; Seeps; Pond and stream margins. Reported height: 2-3 ft.
Growth habit: clumps of upright, sword-like leaves; rhizomes often form colonies. Allow space for this growth between neighboring plants over several seasons, rather than spacing only for the size of a young plant.
Plant specifications
Key growing facts
| Sunlight | Full to partial sun |
|---|---|
| Soil moisture | Wet to moist |
| Height | 2-3 ft |
| Bloom season | Late spring to early summer |
Show / hide ▾Growing & planting details
| Growth habit | Clumps of upright, sword-like leaves; rhizomes often form colonies |
|---|---|
| Root form | Fibrous roots; Rhizomes |
Plant identification & seed reference
| Botanical name | Iris virginica var. shrevei |
|---|---|
| Other common names | blue flag |
| Plant family | Iridaceae |
Planting, growth & seasonal care
Flowering season: late spring to early summer. Use this timing when planning seasonal interest with the other plants in the bed.
Use the selected product option to confirm the supply format and quantity. For a mixed planting, calculate the order from the actual species and layout; a plant’s mature height alone does not determine a seed rate or plug spacing.
Show / hide ▾Plant communities & associatesDocumented community records
Spring Bay Fen Nature Preserve — wet-mesic floodplain forest
Surveyed in 2007, 2008 and 2011. Wet-mesic floodplain forest recorded separately from the adjoining fen. These dated records do not establish presence today.
Other native plants recorded in this surveyed community: Acer nigrum, Acer saccharinum, Agastache nepetoides, Amorpha fruticosa, Anemone canadensis, Arisaema dracontium, Arisaema triphyllum, Blephilia hirsuta, Carex blanda, Carex emoryi.
Murphy, Phillippe & Ebinger 2021, Appendix 1. Selected associates from the same community; records do not show immediate neighbors or prescribe planting ratios.
Spring Bay Fen Nature Preserve — tall shrub fen
Surveyed in 2007, 2008 and 2011. Tall shrub fen on Lena muck, recorded separately from the adjoining forest and filled upland. These dated records do not establish presence today.
Other native plants recorded in this surveyed community: Acer saccharinum, Amorpha fruticosa, Asclepias incarnata, Blephilia hirsuta, Bolboschoenus fluviatilis, Caltha palustris, Carex hystericina, Carex stipata, Cephalanthus occidentalis, Chelone glabra.
Murphy, Phillippe & Ebinger 2021, Appendix 1. Selected associates from the same community; records do not show immediate neighbors or prescribe planting ratios.
Show / hide ▾Native range & C-value
This is a partial list of native states verified for variety shrevei, using explicitly named native-range endpoints and state floras. Several records apply only to parts of a state. Unlisted states remain unverified here; the broader species distribution and general occurrence map are not used as native evidence.
State nativity describes a broad range. Use the Chicago-region assessment for local context; a state listing does not establish county nativity.
| Wetland indicator — Corps Chicago 2017 table | OBL |
|---|---|
| C-value — Chicago region, Flora 2017 | 5 |
| Chicago-region native — Flora 2017 | Yes |
| Native range — U.S. states | Verified states (partial list): Alabama, Illinois, Kansas, Minnesota, Missouri, Nebraska, New York, North Carolina, Oklahoma. |
| County nativity | Not yet verified; occurrence records do not establish nativity. |
Show / hide ▾Pollinators & wildlife
Caterpillars recorded on Iris — genus-level evidence
These records concern the plant genus Iris, not necessarily Iris virginica var. shrevei. They do not establish a host relationship for every species in the genus, specialist status, or occurrence at your location. The selected insects are listed as native in the source’s North American study area.
Macromoth: Amphipoea americana (American Ear Moth, American Borer); Amphipoea keiferi; Amphipoea pacifica; Ctenucha virginica (Virginia Ctenucha ); Helotropha reniformis (American Crescent Borer, Reniform Celaena, Reniform Helotropha); Lophocampa ingens; Orgyia leucostigma (White-Marked Tussock Moth ); Papaipema cataphracta (Burdock Border, Potato-Stalk Borer); Papaipema nebris (Stalk Borer); Tetracis cachexiata (White Slant-Line); Xanthopastis regnatrix (Convict Caterpillar, Spanish Quaker, Spanish Moth); Xylena curvimacula (Dot-and-Dash Swordgrass Moth ); Xylena nupera (Red Swordgrass Moth, American Swordgrass Moth, False Armyworm).
Micromoth: Endothenia hebesana (Verbena Bud Moth); Endothenia rubipunctana; Moodna ostrinella (Darker Moodna).
Show / hide ▾Frequently asked questions
What are the ideal growing conditions for Southern Blue Flag?
Light: Full to partial sun. Soil moisture: Wet to moist.
Is Southern Blue Flag deer and herbivore resistant?
Species-specific deer resistance has not been verified here. Even plants described as resistant may be browsed. Use physical protection where deer damage is a concern.
When should I expect Southern Blue Flag to bloom?
Typical flowering period: Late spring to early summer. Timing varies with location and weather.
Show / hide ▾Sources & ecological notes
Native range & ecological ratings: Flora of the Chicago Region (2017), via Universal FQA; USACE Chicago FQA (2017).
Growing conditions & other references: Illinois Wildflowers, John Hilty.
Wildlife records: Shropshire & Tallamy: caterpillar hosts (2025).
Native range does not identify the origin of the seed or plants offered. Community and wildlife records apply to the locations and conditions described.
Research notes & credits
USACE/ERDC fqadata — Chicago Region FQA 2017. Herman, B., Sliwinski, R. & Whitaker, S. (2017), Chicago Region FQA Calculator; distributed by USACE/ERDC in fqadata under CC0. Values may differ from Flora of the Chicago Region (2017). CC0 dedication.
Additional reference: Open Database License 1.0.
Flora rating attribution: Kenneth Johnson (2018), Flora of the Chicago Region UFQA Database, following Gerould Wilhelm and Laura Rericha (2017), Flora of the Chicago Region: A Floristic and Ecological Synthesis. Individual rating facts are presented with original commentary; the calculator’s software license is not treated as a license for the underlying Flora publication.
Data adapted from Shropshire, K.J. & Tallamy, D.W. (2025), Lepidoptera of North America, north of Mexico, supplementary material 1. This selected and reformatted host dataset is available under the Open Database License 1.0. No endorsement implied.
Genus-level research records
These records concern the plant genus. They do not establish that each insect feeds on this particular plant species.
| Record ID | Scientific insect name | Common name | Source group | Plant genus |
|---|---|---|---|---|
| 200718 | Amphipoea americana | American Ear Moth, American Borer | macromoth | Iris |
| 200722 | Amphipoea keiferi | macromoth | Iris | |
| 200724 | Amphipoea pacifica | macromoth | Iris | |
| 203646 | Ctenucha virginica | Virginia Ctenucha | macromoth | Iris |
| 206757 | Helotropha reniformis | American Crescent Borer, Reniform Celaena, Reniform Helotropha | macromoth | Iris |
| 207901 | Lophocampa ingens | macromoth | Iris | |
| 209084 | Orgyia leucostigma | White-Marked Tussock Moth | macromoth | Iris |
| 209261 | Papaipema cataphracta | Burdock Border, Potato-Stalk Borer | macromoth | Iris |
| 209281 | Papaipema nebris | Stalk Borer | macromoth | Iris |
| 212378 | Tetracis cachexiata | White Slant-Line | macromoth | Iris |
| 212785 | Xanthopastis regnatrix | Convict Caterpillar, Spanish Quaker, Spanish Moth | macromoth | Iris |
| 212898 | Xylena curvimacula | Dot-and-Dash Swordgrass Moth | macromoth | Iris |
| 212899 | Xylena nupera | Red Swordgrass Moth, American Swordgrass Moth, False Armyworm | macromoth | Iris |
| 204639 | Endothenia hebesana | Verbena Bud Moth | micromoth | Iris |
| 204647 | Endothenia rubipunctana | micromoth | Iris | |
| 208504 | Moodna ostrinella | Darker Moodna | micromoth | Iris |
Earlier taxonomic comparison: retained taxon source. The current state treatment is described below.
State-range sources: Lady Bird Johnson Wildflower Center — Iris virginica var. shrevei; Ladd and Thomas (2015), Ecological checklist of the Missouri flora; Vascular Plant Communities of the Green River Lowlands in Northwestern Illinois; USDA Forest Service, Our Native Irises — Iris virginica varieties. This is a partial list of native states verified for variety shrevei, using explicitly named native-range endpoints and state floras. Several records apply only to parts of a state. Unlisted states remain unverified here; the broader species distribution and general occurrence map are not used as native evidence.
Parts-of-state qualifications in the source: New York western; North Carolina western; Minnesota southern; Nebraska southeastern; Kansas extreme northeastern; Oklahoma extreme northeastern.
Growing guidance: Illinois Extension — Keeping deer out of the yard and garden. Selected facts in original wording. General deer advice is not a species resistance rating.
Additional community records: Murphy, Phillippe & Ebinger (2021), Spring Bay Fen flora and vegetation; Wildflower Center synonym record — Iris virginica var. shrevei. Selected facts and taxonomic links; source spellings and historical survey dates retained.
Plant Shipping & Care
Plant Shipping & Care
We want to ensure that our customers get what they want, a native backyard oasis. To do that, we need to follow a few simple guidelines and give you some information and pointers to make sure you get your plants delivered in a healthy state.
As a reminder, you will receive an email to confirm your pickup or shipping window just before the plants are ready. See Order Fulfillment below for seasonal fulfillment windows.
Choices to Receive Your Plants & Accessories
- Website orders: Seed, plugs and bare-root plants offered for shipping are shipped to your address. Shipping charges are calculated at checkout.
- Container trees and shrubs: Some #3 and #5 container options are offered for scheduled pickup only. Check the selected product option and the cart pickup instructions before ordering. Pickup and shipped items require separate orders where indicated in the cart.
- Wholesale orders: Delivery and pickup are arranged separately according to the order, supplier yard and location. Wholesale pickup is free.
- Pickup locations and dates are confirmed by email. Please wait for confirmation before traveling to a pickup site. Our offices are not retail stores or nursery pickup locations.
Order Fulfilment - When Your Plants or Other Items Will Be Ready
We take orders all year long and seed is shipped all year, but we only provide the plants to you in certain fulfillment windows to ensure healthy plants.
Wholesale Orders
- Shipped or are Ready For Pick Up As Requested.
Retail & Website Orders
- Seed Typically Ships Out Within One Week Of Order All Year Long
- Typically, single species flats ship when ready, sometimes as soon as early to mid-April (depends on weather) through early-October.
- Mixed species kits are batched and shipped as indicated on the product page.
- If a plant order is placed while outside of the plant fulfillment window your plants will be reserved through your payment, however, the order will not be fulfilled and shipped until the following spring. We don't want to provide you plants when they won't be happy during the cold winter months.
- Early in the spring and later in the fall certain species may be dormant or partially dormant with brown leaves, however they will return to grow healthy next growing season.
- Your order may arrive in several different shipments.
- If certain plants within an order will not be available until a later date, we may choose to hold the full order until all are ready. In certain circumstances, we may choose to send them in two separate shipments
- Fulfillment is always dependent upon plant availability. We try our best but sometimes plants do not overwinter well and perish. If a plant is on back order you will receive an email indicating the estimated shipping date. If we can not provide the plant we will first notify you and give you an option of substitution or a refund of that individual species.
- Plants are typically only packaged and shipped on Mondays to ensure they do not sit in the harsh delivery facility for extended periods of time over the weekend. You will receive a confirmation email once your delivery has been shipped and to estimate your delivery date.
- Apparel & accessories are ready typically within one to two weeks. See product page for holiday shipping.
Where We Ship

What to Expect When Receiving Your Delivery
- Your plants will be packaged with the utmost care
- We will need to cut back certain plants prior to shipping. This seems counter-intuitive, however, the fewer leaves the less water the plants can lose during shipping, resulting in healthier plants for you. This also enables the plants to fit within the protective packaging and shipped safely.
Shipments
- Larger plant shipments will look similar to the picture below with a tray of your plants and a cardboard box to protect them during shipping.

What to Do With Your Plants After Receiving Your Delivery
- Unpack your order IMMEDIATELY
- Inspect for damage and report any issues immediately to Natives@NaturalCommunities.net
- Water your plants
- Install your plants as quickly as possible and water the entire garden area thoroughly
- If you cannot install your plants immediately
- Some plants may not be in a container, put them into some kind of a container such as a paper cup with loose soil until installation
- Make sure each plant is receiving the appropriate amount of light.
- Continue to water daily each morning and possibly again in the afternoon
- No additional fertilizer is needed

Seed Shipping & Care
Seed Shipping & Care
Seed ships all year and typically ships within a week of an order being placed.
We have attempted to put together some basic information regarding native seed installation, establishment, and maintenance. We hope you find it helpful. If you need further assistance on native seed establishment, please schedule a free consolation call here.
Consultation Services
Ecosystem Restoration Considerations
Native Seed Establishment Best Management Practices
Native Seed Stratification Best Management Practices
Solving a Site Problem? Get Expert Advice + Get Store Credit
Whether you're fighting severe erosion, replacing invasive species, designing a pollinator haven, or seeding large acreage, choosing the wrong species wastes time and money. Talk 1-on-1 with a restoration ecologist to map out the exact species, plug counts, or seed mixes for your soil and goals. Book a consultation and get all or a portion credited directly back to your order.