Canadian Middle Arctic Tundra

The most widely distributed tree in North America - a slender, cool-climate deciduous tree famous for nearly round leaves on flattened stalks that flutter ("quake") in the lightest breeze and turn brilliant golden yellow in fall. Smooth greenish-white bark whitens to chalky white with black warty patches as it ages. In the wild, aspens grow in clonal groves rising from one shared root system, so an entire grove can be a single genetic individual, all male or all female.

A tall, bold warm-season annual from Mexico and Guatemala (the "African" name is a misnomer of its European garden history) grown for large, fully double, pompon-like flowerheads in saturated yellow, gold, and orange over strongly aromatic, finely divided foliage. Plants reach 1 to 4 feet and bloom from early summer to frost in full sun. The petals are edible and used as a culinary garnish and natural dye, and the flowers are the iconic "flor de muerto" of Mexican Day of the Dead. Despite the wide listed zone range it is frost-tender and grown for a single warm season.

A dense, conical-to-narrow-pyramidal evergreen tree native to eastern and central North America, prized as a screening and foundation conifer. Flat, fan-like sprays of scale-like, aromatic yellow-green foliage clothe the tree from the ground up, and red-brown bark exfoliates on mature trunks. Wild trees can reach 40 to 60 feet but cultivated plants typically stay near 20 to 30 feet; small urn-shaped cones and dense evergreen cover make it valuable food and shelter for birds.

A medium-to-large native shade tree of central and eastern North America, reaching 50 to 80 feet with an ovate-rounded crown and large, asymmetric heart-shaped leaves. In June it carries pale-yellow, intensely fragrant flowers on pendulous cymes - each cluster hung from a distinctive strap-like leafy bract - that ripen into pea-sized nutlets. The fragrant June bloom is a premier nectar source: Missouri Botanical Garden lists it as attracting bees and butterflies, and the Lady Bird Johnson Wildflower Center flags it as having special value to both native and honey bees.

Amur maple (Acer ginnala, accepted by Kew's Plants of the World Online as Acer tataricum subsp. ginnala) is a small, fast-growing deciduous tree or large multi-stemmed shrub from northeastern Asia - the Russian Far East, northeastern China, and Korea. At 15 to 20 feet it fits where a full-size maple cannot, and it earns that place with three seasons of interest: fragrant greenish-yellow flowers in spring, which is an unusual scent for a maple and an early nectar source for bees; small glossy three-lobed leaves through summer; and reliable, often brilliant red-to-orange fall color that arrives early. It is also one of the hardiest maples, tolerant of cold, wind, dry soil, and a wide range of pH. The honest catch, and it is a serious one for North American gardeners, is that it self-sows prolifically and has escaped cultivation to become invasive across parts of the US Midwest and Northeast, where its shade-tolerant seedlings crowd native shrubs and understory trees in open woods, savannas, and prairies. Several states list it as invasive or a noxious weed. Check your local invasive-species list before planting, and be prepared to remove seedlings if you do.

A native eastern + central North American multi-stemmed deciduous shrub with dentate (toothed) foliage, white spring flower clusters, blue-black drupes, and reliable fall color. Especially valued for wildlife - among the most-cited native shrubs for fall-migration bird forage.

A fast cool-season annual of the mustard family grown for its peppery, mustard-like salad greens - irregular, pinnately-lobed basal leaves in a low rosette, each with 4 to 10 small lateral lobes and a large terminal lobe (Missouri Botanical Garden). First cultivated by the ancient Greeks and Romans and still widely grown across Europe, it is best grown in the cooler spring and fall months rather than summer heat; leaves are harvested young and tender before they turn strong and bitter. Pale-yellow four-petalled flowers with dark brown or purple veins appear in corymbs if plants are left to bloom.

A cool-season Asian leaf vegetable grown for its loose, non-heading rosette of dark-green leaves carried on broad, juicy white stalks - the spoon-shaped petioles that distinguish it from heading cabbages. Missouri Botanical Garden PlantFinder records that the group spans varieties from 3 to 4 inches to 24 inches tall and is edible at every stage, from seedlings to small immature heads to large mature heads and even while flowering. The stems are mild and juicy while the leaves carry a cabbage-like flavor; like other brassicas it tolerates light frosts but bolts in summer heat.

A rough, sprawling Mediterranean annual grown for showy, open racemes of drooping, star-shaped bright blue flowers in summer. Branched stems and wrinkled, dull gray-green leaves are clad in bristly hairs and carry the taste and fragrance of cucumber. Easy in poor, dry soils, drought-tolerant, a magnet for bees, and a self-seeder that returns to the garden year after year.

Boxelder (Acer negundo) is the maple that does not look like a maple. Instead of a single lobed leaf it carries compound leaves of three to five toothed leaflets, close enough to poison ivy that people regularly misidentify young shoots, and it is one of the very few dioecious maples - male and female flowers on separate trees, so only the females carry the familiar paired samaras. It is native across an extraordinary sweep of North America, from Maine to Manitoba and south to Florida, Texas and central Mexico, and it is genuinely at home on riverbanks and floodplains where its speed and flood tolerance are assets. In a garden it is usually a volunteer rather than a choice. It grows fast, breaks in storms, seeds everywhere, and hosts the boxelder bug, which overwinters on house walls in numbers that make it a household nuisance rather than a garden one. The case for it is narrow but real: it establishes on ground where better trees fail, in cold northern climates and on raw disturbed sites, and it is a documented larval host for cecropia and a valued early honey-bee forage.

A cool-season vegetable grown for its large, tight, terminal head of green flower buds on a thick edible stem, framed by waxy blue-green leaves. Grown as an annual; it grows poorly once daytime temperatures consistently exceed 80°F, so it is timed for spring and fall. Harvest promptly while the head is firm and tight, before the buds begin to open.

A slow-growing, long-season cool-weather vegetable grown for the miniature cabbage-like buds (1 to 2 inches wide) that form in the leaf axils along a single 2-3 foot stem. It is the same species as kale, cabbage, broccoli, cauliflower, and kohlrabi, differing only by cultivar group. Flavor improves after the first fall frost, so it is timed for a cool-temperature autumn harvest rather than summer heat.

A cool-weather leaf vegetable grown for its dense, edible head of tightly wrapped blue-green, red, or wrinkled (Savoy) leaves. A biennial almost always grown as an annual, it forms a 3-4 pound head in about 80 days and rarely flowers in cultivation. It shares its species with kale, Brussels sprouts, broccoli, cauliflower, and kohlrabi, and grows poorly once daytime temperatures stay above 80°F.

An Old World cottage-garden annual grown for daisy- to chrysanthemum-like flowerheads (3 to 4 inches across) in bright yellow through deep orange, often with a contrasting darker center disk. In cool climates it blooms over a long summer-to-fall window; in hot summers it tends to languish and may need a midseason cutback to rebloom. The somewhat bitter flowers and lance-shaped aromatic leaves are edible, and the petals lend color to soups, rice, and baked goods.

A warm-season annual vine in the cucumber family grown for its sweet, aromatic netted melons - one of the six broadly accepted edible groups of the polymorphic Cucumis melo. Stiff-haired, rough-textured trailing stems climb 6 to 9 feet with the help of unbranched tendrils, carrying funnel-shaped yellow flowers that draw bees. Native to the Old World (Africa, the Arabian Peninsula, India, New Guinea, and Australia) and intolerant of frost, it is grown as an annual on the ground or on cages and trellises.

A cool-weather brassica grown for the large, tight head of aborted white flower buds - the "curd" - that forms at the center of a rosette of broad blue-green leaves. The same species as cabbage, broccoli, kale, Brussels sprouts, and kohlrabi, it is harvested before the curd ever opens into true flowers. Grown as an annual; notoriously fussy, with little tolerance for heat, drought, or cold, it does best in the cool temperatures of spring and fall.

A suckering, thicket-forming native cherry that reads as a large shrub or small tree across most of North America. Fragrant white flowers open in elongated drooping racemes in spring, followed by dense pendulous clusters of pea-sized cherries that ripen red to dark purple-black in late summer. The astringent fruit is technically edible after processing, and the plant is a workhorse for wildlife - feeding birds and mammals and hosting sphinx-moth larvae.

A warm-weather annual of the carrot family grown in herb gardens for two distinct crops from one plant: the lacy, strong-scented foliage harvested young as cilantro, and the aromatic dried seed harvested as coriander. The plant bolts and flowers quickly in hot weather, throwing up showy white-to-pale-lavender umbels and a marked leaf dimorphism - broad scalloped lower leaves give way to fine, thread-like upper foliage on the flowering stems. Fast and easy from a direct sowing, it is best succession-planted for a steady leaf harvest before heat triggers bolting.

A cool-weather leafy cabbage relative grown for its broad, leathery, blue-green leaves that grow in a loose upright rosette on a thick stem - never forming a head ("acephala" is Greek for headless). A biennial almost always grown as an annual, it sweetens after a fall frost and, in mild-winter regions, keeps producing leaves through winter until it bolts in spring. One of the most cold-tolerant vegetables in the cabbage family.

Colorado blue spruce (Picea pungens) is a narrow, stiffly pyramidal conifer from the central and southern Rocky Mountains, and the source of nearly every silver-blue evergreen in cultivation. The colour is real and is the reason it is planted: the needles carry a waxy bloom that reads anywhere from grey-green to an almost metallic pale blue, sharpest on selected cultivars. In its native range, between roughly 6,000 and 11,000 feet from Wyoming and Idaho south to Arizona and New Mexico, it is a cool-climate mountain tree of moist stream sides and canyon bottoms. Planted far outside that range - which is where most people meet it - it is one of the most reliably disappointing conifers in the eastern United States, where humid summers bring on needle cast and cytospora canker and a fifteen-year-old specimen often loses its lower branches and never recovers them. It is also planted far too small: the nursery pyramid becomes a 30-to-60-foot tree. Given cool air, full sun, room, and honest expectations, it is superb and long-lived.

A tough, widely adaptable native shade tree of central and northeastern North America, growing 40 to 60 feet tall and wide with a rounded, spreading crown. Mature gray bark develops the warty corky ridges that make it instantly recognizable, and the round purple drupes are edible and feed dozens of bird species. One of the most pollution- and stress-tolerant street and shade trees available - it shrugs off wind, urban conditions, and wet, dry, or poor soils alike.

Common juniper (Juniperus communis) has the largest natural range of any woody plant on earth. Missouri Botanical Garden calls it "the most widespread conifer growing in the world today", and the WGSRPD range mapped in this record runs to 130 botanical countries: a circumboreal band right around North America, Europe and Asia that reaches inside the Arctic Circle, plus one stranded population in the Atlas Mountains of North Africa. Its second claim is in the drinks cabinet. The waxy blue-black "berries" are fleshy seed cones rather than fruit, and they are the botanical that makes gin gin - the spirit category is legally defined by juniper being the predominant flavour, in EU spirit-drink law and in the US standards of identity alike. The honest caveat is that none of that makes it a good bet in most American gardens. MBG records "superior tolerance for cold temperatures and superior intolerance for heat and humidity" and states plainly that it is not recommended for planting south of USDA Zone 6, and it also notes that species plants are rarely sold in commerce - what a garden centre stocks is cultivars. Settle the habit question before buying, too, because the same species is a 9-to-12-inch prostrate mat on an exposed ridge, a 5-to-15-foot multi-stemmed shrub through most of the US, and occasionally a 45-foot tree.

A native North American deciduous shrub with exfoliating bark (hence "ninebark"), white-to-pink spring flower clusters, papery red seedpods, and reliable fall color. Colored-foliage cultivars (Diabolo, Coppertina, Summer Wine) extend the design palette. Adaptable + drought-tolerant once established.

An old garden-favorite annual native to Mexico, grown for showy daisy-like flowers in nearly every color but true blue - red, yellow, orange, pink, rose, lavender, green, and white. Bushy, leafy plants rise on upright, hairy, branching stems and bloom continuously from early summer to frost. A magnet for butterflies and hummingbirds, and one of the most reliable cut-and-come-again cutting-garden flowers.

A fast, low-maintenance warm-weather annual from Mexico and the southern United States, grown for saucer-shaped, daisy-like flowers (2 to 4 inches across) with red, pink or white rays around a yellow center. The lacy, threadlike bipinnate foliage gives an airy texture, and the long bloom run from early summer to frost makes it a workhorse for cutting and cottage gardens. It flowers best in lean soil - overly rich, fertile ground produces leafy plants with fewer blooms.