River oats

Idaho fescue is the plant that the small blue mound in every garden centre is imitating. That mound is almost always Festuca glauca, a European ornamental that dies out in the centre and wants replacing every few years; Idaho fescue is the western North American original, a densely clumping, long-lived perennial bunchgrass with the same fine blue to grey-green foliage on a plant roughly three times the size and with a genuine ecological job. It is a cool-season grass, flowering April to July on stiff stalks that stand about twice the height of the leaf tuft, and it is built underground rather than sideways: thick, deeply penetrating roots carrying symbiotic mycorrhizae, and no rhizomes at all. That is the whole difference between this grass and red fescue, the creeping lawn species in this same group. Idaho fescue never knits into turf, never repairs a gap by running, and cannot be mown as a lawn. What it does instead is hold a slope. The Lady Bird Johnson Wildflower Center calls it drought tolerant and excellent for erosion control, and notes the trap in the same breath: seedlings are only weakly competitive, and only mature plants become strongly competitive. Add that its seed is commercially available but not highly germinable, and the honest summary of establishment is that this is a two-to-three-year project on a weedy site, not a one-season fix. Two more caveats belong up front. There is no Missouri Botanical Garden PlantFinder profile for this species and no RHS Find a Plant entry, so this record rests on a native-plant database and an encyclopedia rather than on horticultural trial guidance, and it is thinner on garden performance than the fescue records around it. And its documented ground is western: rocky slopes and dry openings in woods, from British Columbia and Alberta south through the mountains to central California and Colorado. Nothing cited here describes how it behaves in a humid eastern summer, so this record does not guess.

Mapleleaf viburnum is the small one, the shade one, and the dry one, and those three facts are the whole reason to plant it. Missouri Botanical Garden puts it at 3 to 6 feet tall and 2 to 4 feet wide, which makes it roughly a third the size of arrowwood or blackhaw viburnum and the only member of this group that fits under an established oak without a fight. It is also, in MBG words, generally more shade tolerant than many of the other species of Viburnum, and the Wildflower Center rates its drought tolerance HIGH on dry rocky soils. Dry shade under mature hardwoods is the hardest site most gardeners own and the shortlist of shrubs that actually want it is short; this is on it. The leaves are the field mark and the name: opposite, three-lobed and coarsely toothed like a red maple leaf, 2 to 5 inches long, with small black spots on the undersides that no other viburnum in this catalog carries. Flowers are tiny, white, and held in flat-topped long-stalked cymes to 3 inches across, and the fruit ripens through red to blue-black in late summer. The autumn colour is the pay-off and it is genuinely unusual: MBG calls it excellent reddish-purple to magenta, and Wikipedia records the range as pale yellow through orange to pink, rose or red-purple depending on how much light the plant gets. Pink is not a colour eastern shrubs generally offer. Two honest limits. It suckers, and the Wildflower Center is blunter about it than MBG is - suckers profusely to form large, loose, open colonies - so you are planting a spreading understorey patch, not a specimen. And the fruit crop is thin compared with arrowwood or nannyberry, because a clonal colony is one genetic individual and viburnums generally need a second one. Plant it for the leaves, the ground it covers and the spring azure caterpillars, and treat any fruit as a bonus.

Silky dogwood is not the plant most people mean when they say dogwood, and settling that is the first job of this record. Cornus florida, the flowering dogwood, is a small tree carrying four huge white bracts in April. Cornus amomum is a 6 to 12 foot multi-stemmed wetland shrub whose flowers are tiny yellowish-white things in flat-topped cymes about 3 inches across, and nobody plants it for them. It is planted for blue fruit, for birds, and above all for holding wet ground and streambanks together. The second thing to settle is the winter stems, because silky dogwood is routinely bought as a cheaper stand-in for red-osier dogwood and the buyer is routinely disappointed: Missouri Botanical Garden describes the twigs as purplish brown, which is not the lacquered arterial red of Cornus sericea, and by the second or third year they have gone grey anyway. Where it genuinely beats its siblings is the fruit and the ground it will take. The drupes ripen white and then blue through August, and MBG rates the plant medium to wet while the Lady Bird Johnson Wildflower Center rates its water use high and its habitat as forested seasonal wetlands, floodplains, shrub wetlands and stream and pond banks. That is why it is one of the standard species in riparian restoration across eastern North America, usually planted as a cheap bare-root bundle from a conservation district rather than as a nursery specimen. Two honest warnings. It suckers and it layers - MBG states plainly that branches touching the ground may root at the nodes and that left alone the shrub may spread to form thickets - which is precisely the point on a streambank and a permanent chore against a tidy border. And what arrives may not be what was ordered: Cornus obliqua, the pale dogwood, is treated by many floras as a separate species and by MBG as Cornus amomum subsp. obliqua on a page of its own, the two hybridise where they meet, and conservation-grade stock sold as silky dogwood is frequently one, the other, or a mix.

A tall warm-season bunchgrass that was once dominant across the North American tallgrass prairie - Indian grass produces stiff vertical flowering stems topped with feathery light-brown panicles highlighted by yellow stamens August through October, then golden-orange fall foliage. Wind-pollinated; seeds feed songbirds and small mammals. Drought-tolerant, erosion-resistant, fire-adapted; among the most resilient native grasses for prairie restoration and meadow plantings.

A native evergreen fern with leathery dark blue-green fronds in upright vase-shaped clumps. Among the most drought-tolerant native ferns - useful for drier-shade settings where most other ferns fail. The "marginal" name refers to sori (spore clusters) carried at the leaflet margins. Evergreen through winter in zones 5+; reliably long-lived (20-30+ years).

Korean velvet grass (Zoysia tenuifolia) is an extremely fine-textured, warm-season turfgrass native to East Asia, prized as a low, almost mossy 'no-mow' lawn alternative and groundcover. Left unmown it knits into a dense, undulating carpet of tiny needle-fine blades that mounds and ripples like green velvet - the look that earns its other names, 'temple grass' and 'Mascarene grass.' It is slow to establish but, once knit in, dense and surprisingly traffic-tolerant. Two honest caveats keep it from being a carefree choice: it spreads aggressively by surface stolons (runners) and will creep into beds and over a neighbor's edge unless contained by hard edging, and like all zoysias it is a warm-season grass that turns straw-brown and goes dormant through cool weather - it is NOT evergreen in winter. Its taxonomy is also muddled: many authorities treat Zoysia tenuifolia as a synonym of Zoysia matrella or Zoysia pacifica, so it travels under several names in the trade.