This blog follows on from my last blog: Why are geraniums worth buying for the garden? Clump forming and scrambling geraniums are: as mentioned in my last blog, loose groupings I use reflecting their principal habit, helping me decide on the best location in a border to plant them . To maximise their visual affect both these types are best considered in combination with their neighbours. Ground-cover types can be considered more independently such as an effective weed suppressant . Suitable companions are plants which have strong architectural form, texture and/or colour: but they must be when mature; of similar size as the geraniums to achieve a balanced composition. Phormium, hosta, alchemilla euphorbia, artemesia, iris; grasses and ferns all have species which can make suitable planting partners.
The clump formers are the ones to be most careful with; as many are large growing and can easily smother less vigorous neighbouring plants. Clump formers with small leaves such as some G. sanguineum species do not grow too tall and can be used to the front of a bed; but until established are in danger of being overwhelmed themselves by more vigorous neighbours.
The most commonly found large clump formers in garden centres are Geranium psilostemon, the Armenian Cranesbill, growing to over 1m tall it’s strong magenta flowers can make a bold contrast with yellow.
Geranium x oxianum and its cultivars, ’Wargrave Pink’ and ’Claridge Druce’, are the ones I know the names off, but I cannot tell them apart and I do not think many people can. Having tried to distinguish them I question the accuracy of labelling and much literature which seems to be very vague. What is important is knowing that they grow to around 60cm and have masses of pink flowers which last over a long period throughout the summer. This allows me to partner this hybrid with a suitable complimentary planting.
It is when one wants to know how to accurately identify a species or cultivar that one realises how vague and repetitive many books and internet descriptions are. I conclude that most authors , have looked similar resources as myself and could not identify these plants with any expertise themselves.
This brings me to these blue flowering geraniums and I confess at the moment I cannot identify them with certainty. The list includes G.himalayense, G. himalayense ’Gravetye‘, G. ‘Brookside’ and the infamous Geranium ’Johnsons Blue’, (a cross of G. himalayense and G. pratense) it is probably the best known clump former and being sterile does not set seed. It’s merit is said to be its abundance of long lasting flowers. The plant sold to me as Geranium ’Johnsons Blue’ has not has not impressed me with an abundance of flowers, perhaps it’s a G.himalayense, although it has not noticeably set seed. So perhaps it is. I am confused.
On a positive note I can identify the hybrid G. ’Orion’ it grows to around 60cm and flowers abundantly and over a long period of time. G.himalayense is claimed to be one of the parents.Clump formers consist of a central rosette of basal leaves from which flowering stem leaves emerge. These are the parts that tend to flop over look untidy after flowering or smothering neighbours. These flowering stems can however be traced back into the basal rosette, cut away unnoticeably leaving a tidy clump.
The tall growing clump formers identified with larger leaves are most suited to the middle of the bed and partnered with plants of equal vigour and for prolonged interest strong architectural leaf form and texture such as tall growing irises or grasses. As they get taller tend to collapse and can look untidy after flowering. If I get round to it I cut these hard back and mulch with a light layer of home- made compost , (a light sprinkling of any fertiliser should do)they always leaf up again but much tidier and some years I get a second flush of flowers.
Because of their loose growth habit of their foliage scramblers do not really make effective groundcover but are excellent for growing through other plants making them really fun to work with. With as many failures (or learning curves) as successes I enjoy experimenting with increasing the dramatic effect they can make as they work they way through neighbouring plants.
G.wallichianum ‘Crystal Lake’ scrambling and harmonising with the burgundy leaves of through an Acer palmatum. Its flowers are just appearing adding to the composition.
Geranium ’Ann Folkard’ ( a G. procurrens and G. psilostemon cross) is a compact scrambler easily identified from other magenta flowering geraniums ( such as G.psilostemon ) as the foliage is a yellowish green and although it could be said to look chlorotic it can harmonise or contrast well with other foliage it merges with.
Personally I believe cranesbill geraniums are must have plants for anyone wanting to invest in long lived, hardy, easy to grow plants able to contribute to all areas of a planting display not only the front, middle and back areas of a planting but transcending these layers by scrambling through them . My aim is to master their identification perhaps its time for me to invest in Peter Yeo’s book, Hardy Geraniums.