#ProPlantTips, Best Plant Picks, Perennial Care

Classic Colors Blue & Purple Flowering Perennials

Charlotte Weidner | February 14, 2026

Blue and Purple colors are both resplendent and mysterious, with a beautiful depth of hue. Flowering perennials in these colors are very popular for so many reasons!

Cool and calming, soothing tones, they can be used in a very relaxing collection by themselves. Blue flowers represent hope and connection to the natural world. They also act as a perfect backdrop for contrasting yellow and orange, or pink and white blooms!

Blue Flowers...Nature's Rarest Color!

Here at NatureHills.com, we've made a name for ourselves with our gorgeous blue-flowering plants! Chinese Blue Wisteria tree, Chaste trees, Blue Chiffon Rose of Sharon, Bluestem Grass, and Blue Girl Hybrid Tea Rose - all are some of our top-selling plants!

No wonder, as true blue flowers are the rarest of all flower colors. In fact, only a few plants worldwide pull off that feat. We included purple flowering perennials in blue tones. That's because these complementary partners flow together in an impressive river of color. Create a magnificent showpiece to rest and relax in with help from our exquisite online catalog of naturally blue-flowering perennials.

Think in terms of layers for a lush look. Fill the space with small trees, shrubs, and perennials, placing smaller plants on the south side of taller ones. Low-growing blue or purple blooms can be found in our Groundcover section. They fill in to soften and polish the edges of your plantings.

High Contrast Blue and Purple Flowers Make a Dynamic Presentation

Placing several contrasting bloom colors in a certain area will definitely create outstanding focal points of interest. Pick your favorite color combination...dark green leaves, soft pinks, and blues make a dreamy impression!

Red-hot scarlet or orange-colored flowers are a compelling companion, while pairing with yellow creates a vivid impact. Or, chill things down with icy white-flowering plants.

Try a Daisy May Shasta Daisy and Purple Rooster Bee Balm in a grouping. Mix and match to create happy beauty that you'll be amazed by every time you see it! Create a lively and colorful landscape by finding that perfect plant pairing. It's so gratifying to follow your passions, isn't it?

Add early-season flowering blue or purple perennials. Then finish with late bloomers for visual interest all season long. Plan to overlap the season of blooms with three or four different varieties. When one perennial blooming period is exhausted, you can have another ready to take its place in the spotlight.

Go beyond the garden bed and pot these up in containers, planters or even hanging baskets! You’ll enjoy armloads of cut flowers for your vases and floral arrangements, too!

A Sample Planting for Blooms All Season

Install landscaping garden plants that look great all year, with good plant choices. Start with trees and shrubs...then add flowering perennials that bloom through the season.

Here is a sample garden design plan guideline of choices that would produce a season filled with blue or purple flowers:

Start with tiny Bulbs like Siberian Squill and Hyacinth that are very easy to plant in the fall. These satisfying bloomers start early in spring and will continue for weeks.
Add spiky texture like Globe Thistles or Sea Holly and purple Allium.
Dramatic dark purple Caesar's Brother Iris kicks in with its architectural, blade-like leaves. Try them near the blue-green foliage of Adam's Needle Yucca as a striking garden feature.
The Blues Little Bluestem Grass would be another stunning option. Or use Blue Rug Carpet Juniper Groundcover for ready-steady steely blue tones all year long.
Soften your early summer with vertical accents like Blue False Indigo Baptisia. These native subshrubs add a bold form and very attractive features.
Don't forget a Blue Chiffon Rose of Sharon tree form for a pretty focal point! Blue Diddley Chaste trees have blue-toned blooms, and can easily anchor a patio planting bed.
Finish up the mid to late season with a collection of Asters. The local butterfly population will thank you for the late-season nectar resource!

Certain extraordinary flowering perennials have extended blooming periods. Consider using these plants as your workhorse or mainstay! Create an eye-catching display with these majestic colors. You'll never grow tired of elegant blue or purple blooms! That's a good thing, as these durable perennials will come back for you year after year.

Top 3 Blue and Purple Flower Choices for Heat and Humidity

May Night Salvia takes center stage with a long season of bloom. Just snip the first spent flower spikes of the season.
Long-blooming Rozanne Geranium with purple petals fills in for a carefree, pretty summer! Azure Rush Geranium is another lovely choice.
Native Bee Balm is a vigorous, nectar-rich grower that belongs in Pollinator Gardens for bees and butterflies. They can also be grown in deep outdoor containers to stop the spread.

Top 3 Blue and Purple Flower Choices for Dry Heat

Give fragrant Grosso Lavender sharply-drained soil for incredible performance, or keep it for years in containers.
You can't beat Sapphire Surf Bluebeard for the sheer abundance of blooms in the second half of the season!
Water-wise Dwarf Lily of the Nile gives you so much but is easy to grow and drought-tolerant.

Top 3 Cold-Hardy Blue and Purple Flower Choices

You'll never get tired of the compliments from bold native Blazing Star Kobold Gayfeather!
These powdery blue flowers of Blue Glitter Sea Holly make an incredible feature in containers and borders.
Get lovely spring blooms and electric orange fall color with fine-textured Amsonia.

Top 3 Blue and Purple Flowering Perennials for Shade

Partial shade lover Rapido Blue Carpathian Bellflower has blue-petalled flower power that won't stop.
You'll love our large collection of Hosta. Add three, four, or more varieties in a coordinated shade display for little care.
Exquisite Maggie Daley Astilbe gives your daily dose of dynamic feathery flowers in pretty purple hues.

Saturated Blue or Purple Flowers For a Serene Landscape

Let Nature Hills help you turn your garden design into a thoughtful composition! A landscape filled with wistful blue and regal purple will grow into a joy to share with your loved ones. You'll appreciate our large online inventory, but please move quickly to order your favorites. Everyone loves blue and purple flowers, after all!

NatureHills.com grows healthy, well-rooted perennials that you can count on to return for years to come!

Check out these great videos on Blue Perennial Selection and Purple Perennial Selection!

Previous Next

Frequently Asked Questions

How often should I water newly planted blue and purple perennials, and what's the target amount once they're established?

Water newly planted blue and purple perennials daily for the first week, then reduce to every 2-3 days for the following month while roots establish. Once established (typically after 6-8 weeks), most perennials need about 1 inch of water per week, including rainfall, delivered through deep weekly watering sessions. In zones 3-5, reduce watering frequency in fall to help plants prepare for dormancy, while zones 6-9 may require consistent moisture through autumn. Check soil moisture 2-3 inches deep before watering and adjust based on your specific varieties, as some like astilbe prefer consistently moist soil while others like salvia tolerate drier conditions.

How much sun exposure do blue and purple perennials such as Bellflowers or Russian Sage need—full sun, part sun, or part shade?

Most blue and purple perennials like Bellflowers (Campanula) and Russian Sage thrive in full sun to part sun conditions, requiring at least 6 hours of direct sunlight daily for optimal flowering. Russian Sage is particularly sun-loving and performs best with 8+ hours of full sun, while Bellflowers can tolerate part shade in zones 7-9 but produce fewer blooms. In northern climates (zones 3-6), these perennials need maximum sun exposure to compensate for shorter growing seasons. Plant them in your sunniest garden spots and avoid areas with less than 4 hours of direct sunlight for best results.

Which USDA hardiness zones are best for popular blue and purple perennials like lavender, catmint, and salvia?

Most popular blue and purple perennials thrive in USDA zones 4-9, though specific varieties have different requirements. Lavender performs best in zones 5-9, catmint is hardy in zones 3-8, and salvias range from zones 4-10 depending on the species. Hardy varieties like 'Munstead' lavender and 'Walker's Low' catmint can survive zone 4 winters with proper drainage and mulching. Check the specific zone rating for your chosen variety and plant in spring after the last frost date for best establishment.

When is the best time to plant early-blooming blue and purple perennials like tiny bulbs (Siberian Squill, Hyacinth) in fall?

Plant early-blooming blue and purple bulbs like Siberian Squill and Hyacinth 6-8 weeks before your first hard frost, typically October through November in zones 3-8. The soil temperature should be consistently below 60°F to prevent premature sprouting. Plant small bulbs 3-4 inches deep and 2-3 inches apart in well-draining soil. Mark planting locations now since these bulbs will emerge before most other plants break dormancy in spring.

How can I ensure continuous blooming all season with blue and purple perennials by overlapping varieties?

To achieve continuous blooming with blue and purple perennials, select varieties with staggered bloom times from early spring through fall. Start with early bloomers like Purple Rock Cress (April-May), transition to mid-season performers such as Catmint and Salvia (June-August), then finish with late-season options like New England Aster (September-October). Space plantings 18-24 inches apart in zones 4-8 for optimal performance. Deadhead spent blooms regularly and choose repeat bloomers like Rozanne Geranium to extend flowering periods throughout the growing season.

How do I deadhead blue-violet Bellflowers or other perennials to extend their blooming from late spring to late summer?

To deadhead blue-violet Bellflowers and similar perennials, cut spent flower stems back to just above the next set of buds or leaves using clean pruning shears. For Campanula varieties, remove faded blooms weekly throughout the growing season, cutting stems back by one-third to encourage fresh growth. In zones 3-8, begin deadheading in late May and continue through August for continuous blooms. Check your plants every 5-7 days and snip stems just above healthy foliage to maintain the plant's natural shape while promoting new flower production.

Which blue and purple perennials are deer and rabbit-resistant, and which ones should I avoid if wildlife is a problem in my garden?

For deer and rabbit-resistant options, choose Russian Sage, Catmint, Lavender, and Salvia - their aromatic foliage naturally deters wildlife while providing beautiful blue and purple blooms from late spring through fall. Avoid Hostas, Delphiniums, and Campanulas, as deer and rabbits consider these garden candy and will quickly devour new growth. Asters and Bee Balm fall somewhere in the middle, with younger plants being more vulnerable than established specimens. Plant aromatic varieties in zones 4-9 depending on the species, and consider surrounding vulnerable plants with deer-resistant companions for added protection.

What pH levels do perennials like Pearl Deep Blue Bellflower prefer—neutral to alkaline soil?

Pearl Deep Blue Bellflower (Campanula) thrives in neutral to slightly alkaline soil with a pH range of 6.5-7.5, though it tolerates slightly acidic conditions down to 6.0. Most bellflowers are quite adaptable to various soil pH levels but perform best when the soil isn't overly acidic. Test your soil pH with a digital meter or soil test kit, and add lime in fall if your pH drops below 6.0 to ensure optimal flowering performance.

How do I identify if a purple flower in my garden is a true perennial or an annual based on roots or tags?

Check the plant tag first - it will clearly state "annual," "perennial," or "biennial" along with hardiness zones (perennials typically show zones 3-9). If there's no tag, examine the root system in fall: perennials develop thick, established root crowns or spreading root systems that overwinter, while annuals have thin, shallow roots that die completely. Perennials also tend to form clumps that expand yearly and may produce basal foliage rosettes in late fall. When in doubt, research the specific plant name or consult your local extension office for identification help.

Why are my blue and purple perennial flowers fading or not vibrant—is it due to low magnesium, phosphorus, or age?

Blue and purple perennial flowers typically fade due to insufficient phosphorus rather than magnesium deficiency, as phosphorus directly supports bloom intensity and color development. Flower colors naturally diminish as blooms age (usually after 7-10 days), but premature fading often indicates inadequate nutrition or excessive nitrogen that promotes foliage over vibrant blooms. Test your soil pH to ensure it's between 6.0-7.0 for optimal nutrient uptake, and apply a balanced fertilizer with higher phosphorus content (like 5-10-5) in early spring before bud formation.