Craig Dremann's IDAHO THRESHOLDS for the TOP 82 native species

Soil nutrient and organic matter thresholds are needed to be able to produce 100% successful future native seeding projects. Copyright © 2018 by Craig Dremann

Plant list is from "Idaho Native Plants for Roadside Restoration and Revegetation Programs"
Idaho DOT 2006 and "Forbs: Foundation for restoration of Monarch Butterflies, Other pollinators, and from Greater Sage-Grouse in the Western United States" in Volume 36 (4), 2016, Natural Areas Journal

The Reveg Edge, P.O. Box 361, Redwood City, CA 94064 - (650) 325-7333 - Email

Each species, require a minimum nutrient and organic matter thresholds in the top two inches of soil, for their seedling's survival, as you can see at

No links = Thresholds that still need to be determined, using the Waypoint Lab A-17 soil test plus an A-19-2 organic matter test that are run from the top 2 inches of soil taken from next to seedlings of each species, and the tests run, data only, in a bar graph format.

A second soil sample is taken from bare soil within 10 feet of the first sample, to confirm the threshold levels set by the first soil sample. Each soil sample needs to be a one-quart ziplock bag full, which has been sifted through a inch mesh screen to remove any rocks or vegetation matter.

Waypoint Lab protocols and the sample form to send in with the soil samples for the A-17 and A-19-2 tests, can be downloaded at

Waypoint Lab: 4741 East Hunter Ave., Suite A
Phone: (714) 282-8777

Links below, are the test results for the soil nutrient and organic matter thresholds that are needed for seedling survival for each species.

! = Pseudomonas bacteria host plant, that help create the rain clouds--see Discover Magazine 2012 article

Achnatherum hymenoides - Indian Ricegrass
Elymus elymoides - Squirreltail
Elymus trachycaulus - Slender wheatgrass
Festuca idahoensis - Idaho Fescue
Poa secunda - Sandbergs Bluegrass
Pseudoroegneria spicata - Bluebunch wheatgrass

Achillea lanulosa/millefolium - Yarrow Native, perennial
Agoseris glauca - False dandelion Native, perennial
Androsace septentrionalis - Northern rock jasmine Native, perennial
Arabis cobrensis - Sagebrush rockcress Native, perennial
Artemesia ludoviciana - Prairie sage
Aster occidentalis - Western aster Native, perennial
Astragalus convallarius
Astragalus curvicarpus
Astragalus filipes
Astragalus lentiginosus
Astragalus obscurus
Astragalus purshii
Balsamorhiza careyana
Balsamorhiza hookeri - Rock balsamroot Native, perennial
Balsamorhiza macrophylla
Balsamhoriza sagitata - Arrowleaf Balsamroot
Calochortus gunnisoni - Gunnisonís mariposa lily Native, perennial
Calochortus macrocarpus - Sagebrush mariposa lily Native, perennial
Calochortus nuttallii - Sego lily Native, perennial
Cleome lutea - Yellow spikeflower Native, annual
Cleome serrulata - Rocky mountain beeplant Native, annual
Collinsia parviflora - Maiden blue eyed Mary Native, annual
Crepis acuminata - Tapertip hawksbeard Native, perennial
Crepis atribarba
Crepis intermedia - Limestone hawksbeard Native, perennial
Crepis modocensis
Crepis occidentalis
Erigeron corymbosus
Erigeron engelmannii
Erigeron filifolius
Erigeron linearis
Erigeron lonchophyllus
Erigeron pumilus
Erigeron speciosus
Eriogonum heracleoides
Eriogonum niveum
Eriogonum sphaerocephalum
Eriogonum umbellatum - Sulphur-flower buckwheat Native, perennial
Gaillardia aristata - Indian blanketflower
Geum triflorum
Grindelia squarrosa - Curlcup gumweed Native, perennial
Hedysarum boreal- Western sweetvetch
Hydrophyllum capitatum - Ballhead waterleaf Native, perennial
Lepidium densiflorum - Common pepperweed Native, annual/biennial
Linum lewisii - Prairie flax Native, perennial
Lithophragma bulbifera - Woodland star Native, perennial
Lithophragma parvifolia - Woodland star Native, perennial
Lithospermum ruderale - Western stoneseed Native, perennial
Lomatium dissectum - Fernleaf biscuitroot Native, perennial
Lomatium grayi
Lomatium macrocarpum
Lomatium nevadense - Nevada biscuitroot Native, perennial
Lomatium triternatum - Nineleaf biscuitroot Native, perennial
Lupinus sericeus - Blue lupine
Mertensia oblongifolia - Oblongleaf bluebells Native, annual/perennial
Mertensia ciliata
Microseris nutans - Nodding microceris Native, perennial
Penstemon strictus - Rocky mountain penstemon Native, perennial
Phlox gracilis - Slender phlox Native, annual
Phlox hoodii - Hoods phlox Native, perennial
Phlox longfolia - Longleaf phlox Native, perennial
Sphaeralcea munroana - Globemallow Native, perennial
Symphyotrichum ascendens
Symphyotrichum chilense
Symphyotrichum laeve
Symphyotrichum spathulatum - Western mountain aster
Thermopsis montana - Mountain goldenpea
Townsendia hookeri - Hookerís townsend daisy Native, perennial
Trifolium cyathiferum
Trifolium gymnocarpon - Hollyleaf clover Native, perennial
Trifolium macrocephalum - Largehead clover Native, perennial
Trifolium variegatum - Whitetip clover Native, annual
Vicia americana

Artemisia cana - Silver sagebrush
Artemisia tridentata - Big Sagebrush
Ericameria nauseosa - Rabbitbrush


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Updated January 1, 2019