Plants for the Unwatered Crevice

 Several friends' inquiries made me realize this was needed. So here it is. 

These are species I have grown without irrigation, in crevice. I am sure there are more. There are a few things that seem to require being in either/both crevice and unirrigated. 

Know that a "rock garden plant" is subjective, and usually comes down to size and habit being appropriate with your rocks. Plenty of these are too large for a small crevice garden with small rocks and are noted as such. As with any unirrigated garden, performance and show will vary with rain and weather year to year... just like nature. 

Keep in mind that different parts of a crevice garden receive/repel more or less runoff, so plants specific to those are noted. Soil type effects things, too. Generally silt and clay hold more water longer. Also know that all plants will need supplemental (at least weekly) irrigation the first season to get established. 

Also know that Bob Nold’s ‘High and Dry” is basically an encyclopedia of plants that can grow without irrigation in Denver (and this classic book has a rock garden plant chapter). We are a little more limited over here in the hotter/drier Grand Valley.

So here it is. I'm listing possible sources after some and at the end listing several plant sources.

Plants for the unirrigated crevice garden in Colorado. 

(below 6000’asl, like Grand Junction and Denver)

Flower power

Castilleja integra, sessiliflora. C. miniata in shade/wetter.  (seed mailorder, or DBG sales)

Physaria ovatifolia, fendleri, arizonica, and most others but alpina. (Harlequin, Alplains, Nargs)

Phlox nana (not a tiny plant, it creeps.) (High country, etc)

Phlox hoodii (tiny) (rare)

Scutellaria resinosa (in a wetter spot, Denver not GJ, not tiny) (wholesaled by bluebird)

Melampodium leucanthum (not tiny) Plants of the SW, etc.

Zinnia grandiflora (spreads a lot, large gardens only- it will eat your small CG for snack) Plant Select.

Arenaria desertorum hookeri (seems to like afternoon shade) (Nargs, Waterwise, Chelsea)

Astragalus utahensis (short lived with organics in soil) NARGS seed

Astragalus spp, so many other western ones. Nargs, Alplains

Heuchera pulchella, abrahmsii, rubescens, even ‘Firefly’ (in deep shade and or with good runoff)

Ephedra minima/monosperma/regeliana in Denver, not GJ. Spreads by rhizome! (Chelsea, etc)

Liatris punctata- maybe too large for small gardens. Plants of the SW, seed, etc.

Phemeranthes (Talinum) brevifolium, parviflorum, calycinum, sediforme  (capricious, sometimes brief.)

Lewisia nevadense (Nargs, etc)

Oenothera caespitosa (up to 1-2’, some forms are rhizomatous, most are short-lived)

Oenothera howardii (up to 1’ wide) Alplains, Harlequin

Atriplex corrugata (Hates water, ultimately a short shrub, plant in early/late winter) Chelsea

Woody lilies

Yucca nana (mailorder)

Agave toumeyana bella (mailorder)

Agaves, most hardy sp, let’s be honest. 

Nolina greenei is the smallest/hardiest “Beargrass” but big: best behind the CG. (Coldhardycactus, high country, Chelsea, etc)

Lil yellow daisies

Stenotus acaulis (seedexes)

Haplopappus armerioides (alplains, seedexes)

Tetraneuris (Hymenoxys) acaulis, scaposa, and argentea

Calylophus lavandulifolius, C. serrulatus 

Heterotheca jonesii (seed, nargs)

Heterotheca ‘GoldHill’ (available on front range of CO)

Erigeron liniaris (may need to be low/wette)

Lil other daisies

Townsendia hookeri (the best/longest-lived), T. glabella (big-ish), T. spathulifolius, T. incana, etc.

Erigeron tener (super) (nargs)

Aster ericoides ‘Snow Flurries’ can be 2’ or more wide. (bluebird wholesales this)

Erigeron compactus (come. to. daddy.) Nargs

Artemisia frigida- will get too big for some gardens. (seed, Little Valley, etc)

Buckwheats Yo

Eriogonum caespitosum, kennedyi, wrightii (small ssp), jamesii, pulchrum, and more. (NARGS, Harlequin, Waterwise, etc)

Eriogonum umbellatum (ie Kannah Creek) in wetter/shadier spots in Denver (commonly sold)

Eriogonum ovalifolium, all spp except niveum. (seed)

Eriogonum heermanii (ie, var sulcata) - fantastic. (nargs, alplains)

Some Eurasians for ya

Acantholimon spp, especially blue leafed ones, not alpine or green-leafed spp. (nargs, wrightman, etc)

Limonium minutum (nargs seed)

Goniolimon sp that fit in size. (harlequin, nargs)

There are surely countless others species yet to be tried…

Limonium minutum

Africans for the right spot: usually wetter

Aloinopsis spathulata (Ethical Desert, etc) 

Nananthus transvaalensis

Escobaria sneedii (v leei)

Lil Cactus duh

Escobia sneedii, leei, orcutii, villardii, and probably any hardy sp. (Coldhardy Cactus.com, etc)

Escobaria missouriensis, vivapara especially. (many cactus retailers)

Mammillaria heyderi/maeiacantha (cactus retailers)

Echinocereus, most sp, where they fit. In Denver and wetter places, a slope or a rise help keep these drained. 

Opuntia fragilis, small forms like the “potato cactus” 

Coryphantha sulcata- delicious.

I know there are more small cacti. South Americans tend to want irrigation. 

P. pachyphyllus

Penstemon

P. laricifoius, tiny, long-lived, hard to find. (Alplains, mailorder)

P. alamocensis, barbatus, - big plants with wee shadows (Plants of the SW, etc)

P. moffatii (nargs?)

P. pachyphyllus (alplains?)

I know there are many more...

Choice things/Crown jewels/hard to source/Oddballs

Astragalus spathulifolius (rare, seed)

Castilleja scabrida (rare, seed)

Penstemon acaulis- don’t you dare go pester this in nature.

Leptodactylon spp. (rare, seed)

Lepidium nanum (rare, seed)

Chaetopappa ericoides- good luck, witches.

Sphaeralcea caespitosa

Chaemachaenactus scaposa- long lived, hard to find seed.

Linum kingii- way cool.

Hoffmanseggia (Caesalpinia) repens. 

Cymopteris bulbosus. Takes years, hates water.

Worth a shot, I haven’t tried them (enough).

Lewisia rediviva (NARGS)

Artemisia assoana. 

Erigeron elegantulus (NARGS)

Penstemon linarioides. (NARGS, penstemon society?)

Stachys, fuzzy ones

Sideritis sp. (plant select...)

Salvia… most fuzzy asian ones will probably do, but most are too large

Pterocephalus spp. Not in GJ.

Petrophytum caespitosum of desert provenance. 

Convolvulus boisseri, tragancanthos, etc. 

Phlox ‘Lemhi Gem’

Achillea, miniature spp. like serbica, ageratifolia.

Penstemon petiolatus- perhaps on a north side as it happens in nature.

I have not trialled enough Grasses

Bouteloua hirsuta (Denver, not GJ?)

Bouteloua ‘Zig Zag’ very worth a shot in Denver. (Waterwise, High Country)

Lycurus pheoides (oh no, this one is good) (seed)

Muhlenbergia torryi, pungens. (seed from reveg folks in TX, etc)

Eremeoruruefurususus something. Fluffgrass. Annual or nearly so.

Aristida purpurea/longiseta. Often short lived and bad in dog fur. (seed) 

Acnatherum hymenoides (1-2’ if you have space. Great. It’s been weedy for a rare few) (seed)

Hesperostipa comata- big translucent plant, no shadow. 

Buffalograss can work as a “skirt” but will invade/cover rocks in a rainy summer.

I know, I know, there is ruby muhly at Apex, but there is ample space and it gets a little water. 

Koeleria macrantha - someone should try it

Things you’d expect to go without water but won’t (usually)

Arenaria ‘Wallawa Mtn’ (it’s alpine and probably European, actually!) 

Arenaria alfacariensis 

Delosperma (with some exceptions… or they look bad when stressed. They need sun to be happy but need regular irrigation to be in sun…)

Thyme

Sedums (lanceolatum, and a few others allegedly have done it)

Sempervivum (also been a report or two but I am dubious. They are usually alpine plants)

Half the Mesembs/Aizoaceae/Iceplant family, generally. They just haven’t persisted without regular, if minimal, irrigation. 

Erigeron scopulinus

Manfreda maculosa

Zauschneria (Epilobium), generally. I wish they did.

Chamaechaenactis scaposa

Rock Garden retailers, plant and seed:

Brick-and-Mortar

Harlequin's (Boulder) 

Perennial Favorites (Rye, CO)

Aguafria Nursery (Santa Fe)

Plants of the SW (Santa Fe)

Waterwise Gardening (Santa Fe)

Mailorder

Alplains.com 

(Best source of special native seed, he's paring down, so don't take him for granted)

Coldhardycactus.com CO (Mailorder)

Ethicaldesert.com, CO Mail-order

High Country Gardens (mailorder)

Arrowhead Alpines (MI, mailorder)

Wrightman Alpines,(NB, Mailorder)

NARGS seed exchange (every Dec 15th)

Edelweiss Perennials, Canby, OR (mailorder)