Just another example of why Campanula reigns supreme in the perennial garden.  With heart-shaped leaves and clusters of large, white tubular flowers, Campanula alliariifolia grows from two to three feet tall in sun/part shade in Zones 7-9.  Quarts.  (Photo courtesy of Todd Boland, North American Rock Garden society).

This Campanula is ideally suited for the rock garden where it grows to about six inches high and spreads to at least twice that.  Given full sun/partial shade and well-drained soil, it will delight all who see it with its soft blue flowers and attractive green, toothed leaves.  Hardy to Zone 4.  (Photo by Mapouletta (Own work) [GFDL (http://www.gnu.org/copyleft/fdl.html) or CC-BY-SA-3.0-2.5-2.0-1.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons)

Campanula  glomerata "Superba" is a clump-forming Campanula with stems about 20-28 inches
high, terminating in tight, clustered violet bells that are ideal for cutting.  Be sure to cut this "superb" bellflower back after its initial bloom to encourage a second wave of violet clustered bells.  Campanula glomerata "Superba" prefers moisture-retentive soil and sun and will be floppy if it doesn't get enough of it.  Zones 3-8. Quarts. (Painting by C.A.M. Lindman (1856-1928) from Bilder ur Nordens Flora, Wiki Commons and in the public domain.)

I have never been disappointed with any Campanula I have ever grown.  They are
all beautiful and, in my mind, the stars of the garden.  Campanula latifolia "Brantwood," was new to my garden in 2011, and when it bloomed for the first
time, I was more than pleasantly surprised.  I was prepared for beauty, but not for this much of it all at one time.  Campanula latifolia "Brantwood" has 3-4 foot spires with large, intense
blue/violet bells, making it especially useful for the back of the
border, as well as cottage gardens.  This one's definitely a keeper. 
Full sun/part shade and well-drained soil.   Zones 3-9. Quarts.

This stunning, rare white bellflower from the Caucasus Mountains has heart-shaped leaves, arching stems, and white bell flowers that are 
sometimes edged in pink.  You couldn't ask for anything nicer.  Campanula makaschvilii is new to my garden and to my flower knowledge, and I am pleased to be able to offer it.  It grows from 12 to 18 inches tall in sun/partial shade.  Zones 5-9.  Quarts.  This beautiful photo is courtesy of Todd Boland, Member, North American Rock Garden Society.

Campanula is the aristocrat of the garden, and Campanula persicifolia (Blue Peach-leaved Bellflower) is an example of why.  One of the easiest bellflowers to grow and most well-behaved, this lovely blue bellflower grows from two to four feet tall, with stalks dotted with beautiful blue/lavender, saucer-shaped flowers in late spring/early summer that last for quite some time.  The flowers aren't the only thing attractive about this blue bellflower: the bright green, lance-shaped foliage forms neat, spreading rosettes that can easily be divided, and they should be divided every two or three years.  Sun/partial shade.  Zones 5-8. Quarts.

I have been growing both the white and the blue varieties of Campanula persicifolia for over 20 years, and I have yet to become tired of either of these bellflowers.  Like the blue variety, Campanula persicifolia alba grows anywhere from two to four feet tall, likes sun/part shade and moist, well-drained soil.  Divide this pretty white bellflower often to keep it going, and just sit back and enjoy.  Zones 4-8.  Quarts.

Campanula persicifolia "Chettle Charm":  The photo says it all: large white bells gently smudged with violet.  What could be prettier and easier to grow - just like its relatives above.  Zones 4-8, full sun to partial shade, to about four feet.  Quarts.

This Campanula receives my award for the best new perennial grown in 2012 in my nursery.  It is a mystery to me why this Meditteranean native isn't more well known to American gardens because it's one of the loveliest and showiest of the Campanulas.  Campanula primulifolia grows to about three feet (maybe more), so be sure to place it at the back of the border or somewhere in the middle.  It's a long bloomer in sun or shade, easy to grow,
with bright green primula-type foliage and lavender blue star flowers that add a big splash of color for a long time in Zones 4-10.  Quarts.

Campanula punctata is a beautiful, spreading white-blooming, freckled bellflower that makes an attractive ground cover in early summer with its glossy, heart-shaped leaves and large, white bellflowers.  The foliage stays low, but the stalks of Campanula punctata can reach two feet.  This white
bellflower enjoys full sun/partial shade in Zones 4-9. Quarts.

Here is another beautiful spreading Campanula - this one with the same endearing, heart-shaped leaves and large dark pink  bellflowers.  The foliage stays low to the ground, and the flower stalks are from 12 to 18 inches high, making it just right for sprawling over rock walls or peeping through fences.  Full sun/partial shade, Zones 4-9.  Quarts.

The blooms of this Campanula look like someone took the scissors to them:  the blooms are slit, giving a spidery look, or as the name suggests: an octopus look.  The leaves are also heavily toothed on the edges.  This Campanula is not only a curiosity:  it's a lovely spreading, low maintenance groundcover that blooms off and on all summer and into fall.  It is not only ideal for spilling over rock walls, but I have seen it used to great advantage as a container plant.  Full sun, partial shade in Zones 4-9.  Quarts.

This fragrant giant grows from four to ten (that's not a misprint) feet tall and is covered with lavender/blue flowers. Even the green, heart-shaped foliage is attractive. Campanula pyramidalis blooms from late spring to early fall in rich, well-drained soil and full sun/part shade. It is considered biennial or a short-lived perennial, so be sure to let it reseed.   Both blue and white varieties are available and every effort will be made to determine colors, but there are no guarantees.  Zones 3-8. Quarts.  (Photo by Michael Wolf from Wiki Commons)   Available late spring.

Campanula rotundifolia is the perfect example of a showy flower that doesn't have to be tall and grandiose to make itself known in the garden.  Scottish Bluebells have an exquisite, almost understated, beauty all their own.  Growing from six to 12 inches from rosettes of rounded leaves, they surprise with blue/violet or white nodding bells atop wiry stems.  Campanula
rotundifolia is not invasive (drat that word), despite stories to the contrary
by those who may have it confused with another Campanula.  Full sun to
partial shade in Zones 3-9.  This Campanula likes it a little on the
dry side. (Reproduction of painting by Swedish botanist Carl Axel Magnus
Lindman (1856-1928), Bilder ur Nordens Flora, from Wiki Commons.)

Campanula trachelium is a cottage garden favorite.  It
grows to about three feet with ovate, deeply toothed textured leaves and clear violet to purple flowers, single and sometimes double.  Sun/part shade; Zones 5-10. 
Quarts.

Campanula trachelium alba is a cottage garden favorite.  It grows to about three feet with ovate, deeply toothed textured leaves and pristine white bell flowers.  It is perfect for the cottage garden or any kind of garden, for that matter.  Sun/part shade; Zones 5-10.  Quarts.