Perennial geraniums are one of my favorite plant species (yeah, I know I say that about a few of them but this time it’s true) 🙂 This was one of the first plants I started to collect again in this new garden and I’m hard at work searching out other species and cultivars.
In my gardens, this has been one tough plant – most of them lasting for years and performing admirably when I give them half a chance.
- Sun: Sun to Part Shade
- Bloom Color: Purples, Reds, bi-colours, pinks, whites and betweens.
- Bloom Time: from spring to fall depending on species
- Height: 6″ to 24″ depending on species
- Width: 12″ to 36″
- Propagation: division is easiest although seed and cuttings are possible
- Hardiness: USDA 3
- Lifespan: greater than 5 years
- Best Soil: decent garden soil and no water stress
- Potential disease problems: geranium rust although not well known or seen often unless plant stressed
- Potential insect problems: few
- Use: ground covers, rock gardens, general border, pond side, containers – depending on species
Growing Care Tips:
There are several interesting things about this plant you should know about.
1) This plant is one for dampish soils rather than dry soils. Dry soils will quickly turn it into an ugly plant.
2) Think rich woodland edge soil and you’ll be fine with this plant.
3) Division can be done every 2-3 years to keep it growing and blooming heavily but I tend to put it off for 3-5. This plant has a deep tap root and you do have to be very careful when digging and dividing to get as much as possible ensuring the offsets (new plants) also have some roots on them.
4) Hardiness is variable in hybrids given the range of the plants (world-wide). Some of the European plants are quite hardy and their genetics don’t influence hardiness to much but the fancy blooming Mediterranean species being used in some breeding programs may create some tenderness. I’m always a bit “shy” about some of the new introductions but it hasn’t stopped me so far from adding them to the garden.
5) Most of the geraniums will give you a second flower if you shear them half-way back after blooming. But two things to note here – the first is the second bloom isn’t going to be as heavy as the first and this does take a fair bit of energy out of the plant. You’ll have to feed the geranium a shot of fish emulsion or other organic plant food if you do this so it doesn’t weaken and winterkill because of depleted root reserves.
6) Good luck trying to identify the different species and parentage of hybrids. This is an area in which it takes a microscope and gene testing to determine which is which. If it has geranium leaves, geranium flowers and that spiky geranum fruit – it’s a geranium. Leave it at that. 🙂
More than 250 species
At the moment, we’re growing a small sample of the more than 300 species available throughout the world but I am growing or have grown the following plants (with more to come I can assure you!)
A hybrid plant cross between G. macrorrhizum and G. dalmaticum produced this plant named after the UK city of Cambridge.
Grow this as a good ground cover because it does form a dense carpet of foliage.
- ‘Biokovo’ – I have to start off with the biggest disappointment for me in the entire class of geraniums. This plant was touted a few years ago as being one of the best new introductions of the millennium. Pale washed out whitish flowers on a non-descript foliage earned its neglected status out in the nursery. Unless I obtained the wrong plant, this one is not worth pursuing.
- ‘Cambridge’ purple-violet flowers.
This is a wonderful short little plant, 4-6 inches tall which tends to form more of a rosette in its leave habit than other more sprawling species. The species does range in colour from a pale white to a bright magenta pink. The form I have is one of the brighter pinks and is quite a delight in May and June when it blooms.
You’ll find an abundance of cultivars of this small plant but it’s mostly a plant for the north – reputed not to take the high heat of USDA 7 and higher.
There are several cultivars available in this 18-24 inch tall form with a creeping habit. ‘Kashmir Purple’ or ‘Kashmir Blue’ are the most common although there is a ‘Kasmir Pink’ out there as well.
The foliage on the G. clarkei is a finer cut foliage than many of the other geraniums and this alone gives it garden space.
The most common cultivar of this species is ‘Wargrave Pink’ with its very vigorous growth habit and salmon pink flowers.
18-24 inches tall, this plant is an excellent border plant and should be on every gardener’s hit list for geranium culture.
This is a “sprawling” plant so do plant it next to walkways or at the edge of walls (where it will hang over). It is not compact as are many of the other plants so it doesn’t make a good ground cover. This is a full sun lover that doesn’t tolerate much shade and you’re going to have to water it as it also doesn’t like dry soils.
There are many varieties of this form on the market and most are quite good. ‘Gravetye’ is an excellent creeping form with good blue flowers.
‘Birch Double’ is another with smallish double flower but is not as good as the species for colour and is less vigorous than any of the singles.
This is an extremely hardy form with scented foliage – a truly unkillable plant. This has the fragrant foliage I enjoy (I note this is a fragrance you either like or hate with few folks in the middle).
Heat tolerant but not drought-tolerant.
They are fairly vigorous and can act as a medium fast spreading ground cover.
- “Ingwersen’s Variety’ – pale pink flowers and is the best of this plant.
- ‘Variagatum’ – I’ve grown this and it isn’t very vigorous tending to die out after a few years. Never bothered to replace it.
G. X oxonianum
This hybrid grows to 24 inches and has been less than a hit in my garden (one of the few I lost within 2 years of planting) One of the problems is a significant amount of variation in plants of the same name. Unless you’re a collector, this is probabaly a species to stay away from.
‘Claridge Druce’ a vigorous plant with purple-pink flowers with darker veins. Cut this back hard after flowering because Geranium rust can make it into one of the ugliest plants in the garden.
This is a tall form, up to 24-30 inches in height with a dark, chocolate maroon flower. Not a plant for any place south of USDA 7 It did well enough for me next to a pond but it isn’t as showy as other varieties.
It is a plant for damp shade – a serious woodland edger or damp meadow plant. Do not allow this one to go dry.
Having said that, the flowers are not bright enough to jump out at you – the color is unusual and mosty a collector’s plant.
This species rises up to 18 inches and is a thick foliaged form, excellent for ground cover use. The flowers are a deeper violet with reddish veins and the foliage is a good thick leaf with more rounded form than other geraniums.
Prefers a partial shade
Not often seen in most nurseries but well worth trying.
This Asian species has been hybridized quite heavily giving us some excellent varieties.
It has been ‘tender’ in my USDA 4 garden so count it as hardy in USDA 5 due to its European heritage.
Grown as all the geraniums in dampish soils, forms tend to be taller – ranging from 18 to 36 inches in height and sprawling. Not a compact grower, quite open and floppy; it usually requires some support from nearby plants to keep upright. The open habit stops it from being used as a ground cover as well.
- ‘Blue Chip’ is a good blue form,
- ‘Mrs. Kendall Clark’ is a light violet blue and quite good although nurseries have started selling/producing plants with a lot of variation under this name. 🙁
- ‘Silver Queen’ if you can find it is one of the taller forms with a mature height of 36 inches and white flowers with a touch of pale violet in them.
- ‘Wisley Blue’ is another form and at 24 inches tall with abundant blue flowers is one to be grown.
- ‘Hocus Pocus’ with its bronze leaves and violet-blue flowers didn’t prove to be hardy enough for me to keep going.
One of my favourite geraniums, this one does very well if grown in a moist soil beside a pond. It does relatively poorly in the dryer border. Native to N.E. Turkey its magenta flowers with dark centres shriek out over the garden when it comes to bloom.
It has reached 36-inches in my garden and it’s not uncommon for it to hit 48-inches in a slightly warmer area.
The only downside to this plant is that its finely cut leaves resemble many garden weeds leading to premature weeding in the spring.
A variety ‘Bressingham Flair’ is shorter and without the magenta cast to the flower – it is almost a pink instead (and not so nice as the species so ignore it)
One of the more popular species – hardy from USDA 3-7 with no problems.
Foliage turns reddish in the fall making them a dual season plant.
Wants full sun in damp soils as shade makes it leggy very quickly. Very trouble free if you do this.
There are many varieties of this popular species on the perennial market. A spreading form with good ground cover characteristics, the varieties tend to be in the 18″ tall range.
- ‘Alan Bloom’ compact with magenta flowers
- ‘Alpenglow’ 8-inches with rose-red flowers
- ‘New Hampshire Purple’ is 12-18 inches tall and compact with flowers purplish rather than magenta.
- ‘Splendens’ is a pale pink with violet tones and is 24 inches tall,
- ‘Shepherd’s Warning’ is a compact growing form with bright rose-pink blossoms.
This is a more upright form of geranium rather than the sprawling ground cover forms and it grows to 30 inches or so. Hardiness is normally considered to be USDA 5 but I’ve grown it for a few years until a tough winter took some of them out. Grow in part-shade in damp soils.
They weren’t so outstanding to be on my must-grow list but I mention them for your interest.
The outstanding reason to grow them is that they are the earliest of the geraniums to flower.
- ‘Album’ a white,
- ‘Birch Lilac’ a violet lilac shade,
- ‘Silva’ a pale blue.
Watch out for this one. It has very small white flowers and an expansive habit that more resembles Ghengis Khan than any other geranium I’ve ever grown. From one tiny plant – it grew to conquer a nation! A great ground cover for waste spaces but almost impossible to control.
This Afghanistan native is slightly shorter than other forms and a touch more tender.
‘Buxton’s Variety’ is the most commonly available variety and its dense growth habit and pale China blue flowers are worth a place in most gardens. It has an open sprawling habit so this is a plant for that rock wall or container growing.
‘Confetti’ It has leaves that are streaked with white and is a very vigorous grower both in the ground and in containers. I really liked this plant with its mounds of tiny pink flowers (really tiny). A spreading form in the garden so be careful. I did lose it after 3 years.
Not easily classified – Hybrids
There are other forms on the market that are hybrids and don’t follow an easy classification.
- ‘Johnson’s Blue’ This is the oldest and one of the most popular, being a cross between G. himalayense and G. pratense. An excellent blue colouring and dense growth habit makes this a good plant for border or ground cover. Some variation appearing in nurseries. But grow it.
- Geranium ‘Bertie Krug’ This one won my heart last summer with a tremendous display of pink, star-like flowers on mat-ground-hugging bronze leaves. Excellent plant. But short lived in my garden
- Geranium ‘Jolly Bee’ has been determined to be ‘Rozanne’ and is now discontinued from sale
- Geranium ‘Rozanne’ A stunning bright violet-purple flower that blooms almost all summer on twelve to eighteen inch tall foliage. This is an excellent plant for the planting in the ground or in containers. A Perennial of the Year award winner, I would not have a garden without it. It does as well as any of the geraniums in full sun and I believe it handles drought a bit better than most.
- Geranium ‘Patricia’It had bright magenta-pink flowers with a dark eye and was a visual knockout. Slightly taller at twenty-four inches, it gave a good garden show.
It’s hard to go wrong with this plant. If you want to start growing them, start with ‘Rozanne’ as it’s the longest bloomer. Simply understand this is an easy plant to fall in love with. 🙂