When the thermometer pushes 100 degrees, the winds roar down from the mountains, and the humidity dips, we gardeners scramble for water. Plants in ornamental containers show stress in a day or so. Hanging baskets can dry out even faster. Nursery stock we've propagated and are raising for future planting usually needs to be soaked multiple times a day. In-ground plantings put in this spring are checked and hand-watered. Hot days also present a great excuse to check and recheck the irrigation systems to ensure nothing is blocking the spray heads, they aren't clogged, etc. (read: play in the sprinklers!). And we need to water ourselves several times a day too (I prefer Arnold Palmers in a pitcher...and playing in the sprinklers!). But we often forget to admire the familiar and not-so-familiar garden stalwarts that revel when the conditions turns oven-like.
Most plants that enjoy the weather currently ushering in July are from the five Mediterranean and Modified-Mediterranean climate zones around the world: California/Oregon, Central Chile, Southern Australia, South Africa, and the Mediterranean Basin/Near East. Hot, dry summers are the norm, with relatively cool nights and low humidity. In Portland, we experience these conditions for fewer months than, say, Naples, Cape Town, Santiago, or Santa Barbara (our Pacific Northwest winters are obviously colder and wetter too), but there are many plants happy in all these places that do well here. Here are some of the more unusual ones that grace our gardens.
Fremontodendron ‘Ken Taylor' (Flannel Bush) is one of my favorite shrubs. A hybrid of multiple California species, it blooms with a large deep yellow flower from May onward, needs no irrigation or fertilizer (it lives a short, floppy, and not-so-flamboyant life when pampered), and held its leaves beautifully through recent sub-freezing winter blasts. Several Grevillea species and hybrids perform as stunning, textural shrubs for fast-draining, poor, and even clay soils (which are actually nutritious enough but not user-friendly). From Australia, they often die when fertilized, prefer hot sun, and bloomfor months during the winter. Their red, orange, apricot, and yellow flowers are spidery, unique and displayed wonderfully against fir-like (usually) foliage. Stipa gigantea is a magnificent evergreen grass that is an underused (but better) substitute for Miscanthus (Maiden Grass) or
Cortaderia(Pampas Grass) in our climate. It extends its feathery, weeping awns in April, but holds them intact (but dry) well into winter. They catch the angled morning and evening sunlight superbly this time of year, and need no water or fertilizer (they won't croak if you do, though).
There are countless perennials ready to tackle a hot, dry summer. Origanum libanoticum is a low-growing ornamental oregano (one of several) with shrimpy bracts that hang for months. It excels in pots and sunny, well-drained sites. Zauschneria californica (Californiafuchsia) invites nectar-seeking birds with its fiery red trumpets and will colonize decent swaths of a sunny border. Euphorbia ‘Tasmanian Tiger' (Spurge) takes a little dry shade in addition to fierce sun and its silvery variegated evergreen leaves pop out when surrounded by darker neighbors.
Not everything listed above is blooming as of this posting, but they are definitely growing at various McMenamins locations (namely at the Kennedy School, St. John's Pub, Edgefield, the Chapel Pub, West Linn Pub, and elsewhere). Enjoy, and stay as cool as the plants!