Northern Shade Gardening

Hardy Geraniums

Wednesday, August 5, 2009 Category: Perennials

Geranium ‘Johnson’s Blue’ and Geranium ‘Rozanne’ (cranesbill) have beautiful blue iridescent flowers. My hardy geraniums are flowering in a part shade bed, where their colour brightens the garden. I appreciate the long sequence of blooms in summer and into fall.

The flowers of these geraniums are often described as blue, but compared to the blue of the lobelia across the path, the petals are leaning towards purplish blue. It’s a lovely colour in the garden, with a shimmery sheen when it catches the light.

Geranium 'Johnson's Blue' petals closeup

Geranium 'Johnson's Blue' petals closeup

Geranium Johnson’s Blue has many of these five lobed blooms with shimmery threads running through the petals. These give the flowers a slight iridescent appearance. The petals are a little more blue than Rozanne, which leans more towards purplish blue. The flower of my Johnson’s Blue  started blooming 9 days before Rozanne, but Rozanne was new last year, so that might still be affecting the natural bloom time.

Geranium 'Johnson's Blue' pretty flowers

Geranium 'Johnson's Blue' pretty flowers

The plants of  Johnson’s Blue sprawl a bit more than Rozanne. Mine are about 45 cm (1.5 ft) tall and a little wider. They have a loose structure, and suit a cottage garden style, or being placed next to plants that they can mingle with at the edges. I have mine under a lilac, and they share the space beautifully. There is a tall Aruncus (goatsbeard) perennial to one side, that doesn’t mind the odd blue flower resting on it.

Geranium 'Rozanne' petals closeup

Geranium 'Rozanne' petals closeup

Geranium Rozanne has  a gorgeous purplish blue colour. Like Johnson’s Blue, each flower has a white centre, but the white centre is larger on these flowers. The blooms themselves are a little  larger too, and the individual petals of Rozanne are wider, overlapping more than Johnson’s Blue.

Geranium 'Rozanne' leaves looking fresh

Geranium 'Rozanne' leaves looking fresh

The foliage of  Rozanne is a lighter green colour than Johnson’s Blue. There is  a faint marbling effect to the leaves on this perennial. Mine are a little shorter than than Johnson’s Blue, with the foliage closer to 30 cm (12 in) tall.

The hybrid name for Rozanne is  actually Geranium ‘Gerwat’, but I haven’t seen it sold under that name around here, not even as fine print on a label. I’ve seen Rozanne generally rated for a warmer area than zone 3, but all eight of my plants overwintered fine, and last year had typical temperatures. They just had a bit of leaf mulch that blew over for protection, but seem perfectly hardy. Mine are in a somewhat protected suburban garden, so the wide open zone 3 prairie might be different.

left 'Rozanne' right 'Johnson's Blue' flowers

left 'Rozanne' right 'Johnson's Blue' flowers

Here’s a Rozanne flower on the left, and a Johnson’s Blue on the right for comparison. If you are looking for an informal perennial for the part shade, both of these hardy geraniums are lovely additions to the garden. Give them some neighbours that don’t mind mingling at the edges. They also look great next to a path, especially if you are looking for a plant to soften the edges as they spill over.

Here is a post showing pictures of the pretty blue  Geranium ‘Rozanne’ planted with the lavender blue flowers of Campanula lactiflora (milky bellflower) in my garden.

16 Responses to “Hardy Geraniums” »

  1. easygardener :
    August 5, 2009 at 1:49 pm

    It has got to be G. psilostemon and its various offspring. I can’t resist dark magenta with a black centre. For some reason they never photgraph well for me – the colours look lighter than they are.

  2. Rebecca :
    August 5, 2009 at 3:43 pm

    Beautiful colours on your cranesbill, mine are pink, but these are much more appealing. :)

  3. Northern Shade :
    August 5, 2009 at 3:56 pm

    Easygardener, it sounds like it really brightens up the border. The deeply saturated colours really suit summertime don’t they?

    I have trouble catching the true colours of a few plants too. I’m not sure if it’s me, or the camera, but I have difficulty getting a good shot of my dark rose pink carnations, even with a variety of settings. The pictures end up with an unnatural glow around them.

  4. Northern Shade :
    August 5, 2009 at 4:00 pm

    Rebecca, I have another cranesbill which has a more light blue colour. I think it might be a G. pratense. It’s much taller, and much more floppy. I haven’t really figured out the right spot for that one yet.

  5. Jackie@Ellie Mae's Cottage :
    August 5, 2009 at 8:11 pm

    I love these flowers. I have two nice sized plants in my garden. They bloom early to mid summer and then I cut them back and get a second wave of blooming. -Jackie

  6. Northern Shade :
    August 5, 2009 at 11:08 pm

    Jackie, these ones started blooming in July in my garden, and I’ve been keeping them deadheaded. I let another taller Geranium go, and it has lots of developing seeds on it now that need removing. I should cut it back.

  7. Joy :
    August 6, 2009 at 5:33 am

    I have meant to get this one so many times and have been diverted every time looking at some other plant at the nursery that caught my eye .. maybe I have to wear blinkers .. goggles ? so I can maintain my plant mission point ! LOL
    Wonderful pictures illustrating the colour and structure of the blooms : )

  8. Northern Shade :
    August 6, 2009 at 8:39 am

    Joy, the geraniums are pretty cottage type flowers, and the flowers look especially nice next to an informal path, where you don’t mind them overflowing a little at the edges.

    I laughed at your scenario at the nursery. Like you, I love walking down the aisles, comparing all the different plants, sniffing the flowers, and seeing what catches my eye.

  9. Swimray :
    August 8, 2009 at 3:35 pm

    Wow these are excellent. I have the magentas, but had not seen the blues. I need (want) some. My geraniums stop blooming in the sticky hot humid Virginia summers. Blues and whites in the garden shade make the backyard seem cooler.

  10. Northern Shade :
    August 8, 2009 at 7:24 pm

    Swimray, I’ve heard that Rozanne tolerates hot summers better than Johnson’s Blue, but haven’t been able to test that for myself in the garden. :)

    The shades of blue in these geranium flowers are very pretty. I find the combination of blue and white flowers in the garden very attractive too.

  11. tina :
    August 8, 2009 at 9:31 pm

    I like them all. I think you’ve identified Johnson’s blue for me. It does great down here in Tennessee. I like the sprawling habit and the fact it will twine in other plants. I’ve not had luck with Rozanne though I have planted it.

  12. Northern Shade :
    August 8, 2009 at 10:58 pm

    Tina, I like the way it meshes at the edges with other plants too. I have what is supposed to be a tall goatsbeard, but is has grown very short, so the Johnson’s Blue flowers were able to grow at the same height, and lean against the white, fluffy plumes. I really liked the combination. It’s interesting to hear that Johnson’s Blue does better for your than Rozanne.

  13. Barbara :
    August 22, 2009 at 12:30 am

    Due to my temporarily absence from blogland I now have to catch up a lot of posts. I start with this one, describing one of my favourite plants in the garden, the blue sorts of geranium. There are several of them in my garden and I especially like the “new” Jolly Bee. Johnson’s Blue was my very first geranium, many years ago, and it is still flowering very well (full sun). Rozanne I only bought three years ago and doesn’t do so well, probably due to the place (shadow from a taxus tree).

  14. Northern Shade :
    August 22, 2009 at 7:43 am

    Barbara, it’s good to hear from you again. My geraniums are in part-shade, so they get a fair amount of blooms, but maybe not as many as if they were in more sun. It’s interesting to hear that Jolly Bee is your favourite geranium. I wondered if it performed differently than Rozanne.

  15. Anne, Long Island, NY Zone 7 :
    November 12, 2009 at 3:07 pm

    Johnson’s Blue was my first as well and I love it but it always stops blooming in our hot, humid summers and doesn’t bloom again ’til spring. I got ‘Jolly Bee” last year and it bloomed until a few days ago. ( direct morning sun,part sun midday, no direct sun after 2pm) I think it’s as beautiful as Rozanne but one of my 2 Rozanne plants is still blooming on Nov. 12th after 2 frost nights. It’s growing behind and up through a Knockout rose so was protected from the frost which stopped the other more exposed Rozanne from blooming. Blue geraniums are definitely my favorite. Has anyone tried G. Sateen?

  16. Northern Shade :
    November 12, 2009 at 6:30 pm

    Anne, I’ve found the Rozanne geranium to have a longer bloom time and a little frost tolerance too. We had a week where it went down to well below freezing, and there were still some Rozanne flowers. I was very surprised by its resilience. They must look especially pretty combined with your knockout roses. My Johnson’s Blue had a shorter blooming time, even though we didn’t get extended hot summer temperatures. I’ve been wanting to try ‘Jolly Bee’ too, and it sounds like yours has a long flowering time.

Leave a Reply