This summer, after another exceptionally hot July, I have found myself increasingly impressed by the plants that simply take heat and drought in their stride and don't need supplemental watering. I've always had a soft spot for silver-leaved plants such as santolina and lamb's ear, which seem to relish the conditions that leave other perennials struggling.

Of course, there is no such thing as a plant you can put in the ground and literally never water. Every shrub and perennial will need some care while establishing, particularly during its first and even second year. But after a few growing seasons, there are many species that can survive perfectly happily on rainfall alone, even during prolonged dry spells.

So, if you are looking to create a more resilient plot, it is worth exploring these low-maintenance backyard ideas that pair beautifully with the plants below. And if you want to capture a Mediterranean feel, start with something like a tough Spanish lavender (live plants are available via Amazon). Here are seven of my favourite plants you never need to water once established.

1. Lamb's ear

Native to Turkey, Armenia and Iran, lamb's ear is a drought-tolerant perennial that is hardy from US hardiness zones 4 to 8 and thrives in full sun.

I grew plenty of it while working as a gardener in Italy, where it lined gravel paths and softened the edges of borders beneath olive trees and silver shrubs. Once established, I never watered it, even during the hottest weeks of summer.

You can find lamb's ear starter plants at Amazon.

Lamb's ear dislikes rich, damp soils, instead thriving in poor soil and free-draining earth, where many other perennials struggle. If you are looking for one of the toughest plants you never need to water once established, this is difficult to beat.

2. Lavender

If there is one plant that sums up a Mediterranean summer, it is lavender. Most lavender varieties are well adapted to hot, dry climates, although hardiness varies depending on the species.

You can find live lavender plants at Walmart.

English lavender (Lavandula angustifolia) is generally hardy from US zones 5 to 9, while Spanish lavender (Lavandula stoechas) is better suited to warmer regions, typically zones 8 plus.

Whatever type you choose, lavender performs best in full sun and free-draining soil. In fact, overwatering is often a bigger problem than underwatering. Once established, it is perfectly happy growing in gravelly ground with very little intervention.

3. Santolina

Santolina, or cotton lavender, deserves far more attention than it receives. This evergreen silver plant has evolved to thrive in hot, dry conditions, producing aromatic silver foliage that looks fresh even after weeks without rain.

Find santolina plants via Amazon.

Santolina chamaecyparissus is hardy down to US hardiness zones 6, performing best in full sun and sharply drained soil, whether planted in gravel gardens, borders or edging pathways. Once established, it is exceptionally drought tolerant and rarely requires supplemental watering.

One tip: a light trim after flowering helps maintain its neat, rounded shape and prevents plants becoming woody.

4. Russian Sage

Russian sage is a hardy perennial that produces airy clouds of lavender-blue flowers above silvery stems from midsummer well into fall, creating one of the coolest colour combinations for a sun-baked border.

Hardy down to US zones 4, Russian sage, or Salvia yangii, thrives in full sun and free-draining soil. The silver foliage helps reflect intense sunlight and reduce moisture loss, allowing plants to sail through long dry spells with minimal watering.

You can find Russian sage at Plant Addicts.

Its soft lilac flowers pair beautifully with other silver-leaved plants, such as lamb's ear or artemisia or santolina, while lemon-yellow blooms, including geums and black-eyed Susans, create a striking contrast in my experience.

5. Buddleia

This summer has completely changed my opinion of buddleias. For years, I thought of them as railway plants, but during the heatwaves of this summer, they have simply carried on flowering. Few plants seem better equipped for drought.

One note of caution: Buddleja davidii is considered invasive in parts of the Pacific Northwest, including Oregon and Washington, so always check local guidance before planting.

Compact cultivars such as 'Blue Chip' or 'Miss Molly' are good options, and tend to be better behaved choices for smaller backyards while retaining the same drought tolerance and long flowering season.

Try the 'Black Knight' buddleja, for a dark, moody option, available now via Fast Growing Trees.

6. California Poppy

You will often find California poppies (Eschscholzia californica) self-seeding into gravel gardens, roadside verges, cracks in paving and dry, sandy banks, where they thrive on sunshine and surprisingly little water.

California poppy seeds can be bought via Walmart.

Scatter seed directly where you want plants to grow and, once established, let nature take over. They often return year after year with cheerful orange, yellow or cream blooms.

For more heatwave inspiration, check out our guide to the shrubs that thrive on neglect, and fill your borders with resilient flowering plants that don't mind a bit of drought.

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