Grow These Perennials for Lasting Garden Color

I will never have a garden without ‘Festiva Maxima’ peonies. Their heady fragrance is something that brings me such joy. But doesn’t it always pour when they reach their most glorious? Then they’re not so glorious. Ephemeral blooms build anticipation and punctuate the seasons, but then they’re gone.

The fact is, we all need sturdy, stalwart plants that keep us coming back, and that hold their own while we’re fussing with things like delphiniums. Here are some of my favorite, faithful perennials for extended interest:

‘Blue Fortune’ Giant Hyssop

Agastache ‘Blue Fortune’ is a powerhouse of blooms. From midsummer to surprisingly late in the fall it stands heavy with flowers and flush with bees. The foliage, sometimes used in teas, has a downy texture and a fragrance that remind you it belongs to the mint family.

All ‘Blue Fortune’ asks is a little deadheading to keep it tidy. Its stems can be pinched back in spring to create a bushier form, though it is naturally less prone to flopping open than some of its taller compatriots. The strongly scented leaves keep most critters at bay. On occasion powdery mildew might strike, but it isn’t particularly prone to the disease.

The easiest way to kill this plant would be to plant it in a wet spot; this hybrid needs a well-drained soil. It can tolerate dry spells once established. It prefers full sun but can take some light shade.

Its spiky blooms suit ‘Blue Fortune’ to the middle or back of the border. Pair it with blue-leaved plants to emphasize the cool tones of the flowers or add yellow-flowering companions for cheerful contrast. USDA Zones 5 to 9.

Hoary Skullcap

For a lesser-known bluish bloomer, try Scutellaria incana, or hoary skullcap. It, too, is a low-maintenance, generous bloomer, with lavender-blue infloresences lasting from mid- to late summer and sometimes later. It, too, is very attractive to bees and not so much to deer. It grows in sun to part shade; in fact it can take the place of a salvia in less than full sun.

Hoary skullcap tolerates a range of moisture levels once established. With more light it requires more moisture. Growing two- to three-feet-tall, it sits well in the middle to back border. A native of much of the eastern half of the United States, it looks at home in naturalistic landscapes and it can reseed to gently spread. When the blooms pass, the calyxes form little shelf-like structures that remain interesting late in the season. For this reason, try combining it with ornamental grasses. The stems can be left up for winter interest and structure.

The only trouble with hoary skullcap? It’s one of those plants that doesn’t look its best in a pot at a garden center. Believe that it can be stunning once established and take the chance if you find it for sale. I can’t imagine a gardener not falling in love with its soft blue blooms. Zones 5 through 8.

Lady’s Mantle

Not every plant can be graced with extended bloom, and some make up for that with other pleasures. Lady’s mantle, or Alchemilla mollis, is an old favorite that will never go out of style. It provides a froth of yellow-green flowers in late spring that will overflow garden beds with welcome exuberance. These soften the edges of pathways and beds; you can cut a few for arrangements to enjoy indoors as well.

But this perennial’s longevity of interest comes from its silvery green leaves. Their hydrophobic nature always stops me to marvel on a dewy morning; water beads up on the geometric palmate foliage for a fascinating show.

This is a sturdy plant that will survive dry periods, but the leaf edges will crisp without regular moisture. Clip the tired foliage to reveal fresh new leaves beneath, and the plant will promptly forgive you the trespass. Pests and diseases pass right by this garden classic, and it’s easily divided over the years. At 18 inches tall and 30 inches wide, it makes a long-lasting edger in part to full sun. Consider it a neutral, as its soft silvery green combines well with many colors. Zones 3 through 8. (Note: Alchemilla mollis is listed as invasive in Alaska and Oregon.)

‘Silver Heart’ Bugloss

For a shady spot, the Siberian bugloss Brunnera macrophylla ‘Silver Heart’ has proved itself an improvement over the classic ‘Jack Frost’, which has been a garden-center standard for years. I've grown both and found that ‘Silver Heart’ has a thicker, downy leaf and as a result it doesn’t turn black and melt in wet, humid weather. And in the terribly hot, dry summer of 2022, this plant remained pert and silvery too.

In spring, bugloss offers a beautiful spray of true-blue flowers similar (in looks, not behavior) to forget-me-nots. It often blooms simultaneously to a deciduous pink azalea in my garden, making a charming combination. The heavily silvered foliage, which forms a mound 12 inches tall and twice as wide, will add elegance to the front of border right up to fall’s frost. Zones 3 through 8.

Bluestars

For a textural delight, Arkansas bluestar (Amsonia hubrichtii) remains unsurpassed, and in terms of care it could not be easier. It provides a cloud of blue flowers in spring. Its fluffy, fine-textured leaves invite contrast with bold-leaved shrubs. It can grow in part sun, but full sun encourages its best structure. Native to dry streambanks and rocky outcrops in parts of Arkansas and Oklahoma, it would be excellent in a planned meadow with grasses and coneflowers (Echinacea) or in the back half of a traditional border. 

In my own garden, I’ve paired A. hubrichtii with foxtail lilies (Eremurus) behind a hedge of Phenomenal lavender (Lavandula angustifolia ‘Niko’). The bluestar masks the lilies as they go dormant; they could do this trick for bulbous alliums, too. This easy perennial attracts butterflies when it blooms, and it goes out with a bang in autumn, its leaves turning gold and glowing in the softer sunlight. Zones 5 through 9.

The related ‘Storm Cloud’ bluestar (A. tabernaemontana ‘Storm Cloud’) offers more willow-like leaves and the added benefit of new growth that emerges nearly black, to catch your interest that much sooner. It also has an extended bloom time and fall foliage that’s a deeper gold. The species grows naturally in wet, sandy sites in the Mid-Atlantic and Upper South, although it can take some drought once established. Its autumn color makes it stunning with other plants that are vibrant in fall, such as blueberry bushes (Vaccinium) or little bluestem grass (Schizachyrium scoparium). Zones 4 through 9.

Two with Silver Leaves

For strictly foliage plants, sun-loving lamb’s ears (Stachys byzantina) and wormswood (Artemesia) will cover swaths of dry ground elegantly. With their felted gray leaves, both these perennials fit easily into most every color scheme. Good drainage is a must, but they demand little upkeep; the most time-consuming task may be trimming them back to constrain their growth or remove unwanted flowers.

The mat-forming Artemisia stelleriana ‘Silver Brocade’ (synonym ‘Boughton Silver’) can put on small yellow flowers that rise above the foliage in a decidedly ho-hum fashion. To keep the focus on the small, scalloped leaves, shear these away. If the plant becomes leggy in summer, cut it back hard to encourage low, tighter growth. Zones 3 through 8.

Some lamb’s ears put on lavender-pink flower spikes that many gardeners choose to remove. To skip this step, look for the cultivar ‘Big Ears’ (also called ‘Helene von Stein’), which seldom blooms at all. Its oval leaves are large and thick, and it is more tolerant of humidity than other selections. Zones 4 through 9.

Both of these foliage perennials blend effortlessly into any plant palette, and their unique leaf shapes open opportunities to play with texture in full sun. Try them with fine-foliage plants like threadleaf tickseed (Coreopsis verticillata), euphorbias or the above-mentioned Arkansas bluestar; spiky-leaved yucca and agave; or round-leaved hardy geraniums and false indigo (Baptisia).

Image credits: Amsonia hubrichtii, Amsonia tabernaemontana ‘Storm Cloud’, Alchemilla mollis and Agastache ‘Blue Fortune’ courtesy of Walters Gardens; Stachys byzantina ‘Big Ears’ by Andria/CC—BY-ND 2.0; Scutellaria incana by Krzysztof Ziarnek, Kenraiz/CC BY-SA 4.0/Wikimedia Commons; Brunnera macrophylla ‘Silver Heart’ by Agnieszka Kwiecień, Nova - Own work, CC BY-SA 4.0; Artemesia ‘Silver Brocade’ by Patrick Standish/CC BY 2.0/Flickr.com