The post by Tabasco gave me an incentive to unpack my books so this is from "The Gardeners Guide to Growing Hardy Geraniums by Trevor Bath and Joy Jones. It is an book from England.
Hardy Geraniums can be propagated by 4 methods: division, cuttings, root cuttings and seeds.
Most HG are very easy to propagate by division. Mature plants of such species as G endressii and its hybrids, G pratense, G phaeum and G sylvaticum will supply more divisions that you know what to do with. Each piece with a root and a shoot is capable of making a new plant quite readily.
Division is necessary to maintain the health of the plant.
The dormant period between late autumn and early spring is usually recommended as the best time for division, but i find that just after flowering, when the plant has been cut back, is very suitable for the operation.
The double forms of G pratense, being sterile, can either be propagated by division or root cuttings. In fact, both operations can be carried out at the same time. In the process of division, many roots will be entangled and damaged or detached. The best of these can be used as root cuttings, being either potted up or inserted into a nursery bed. ( I have done many root cuttings successfully).
Some geraniums have tuberous roots which can be detached and grown on.
Some HG which produce long trailing stems can be propagated by cuttings. Side shoots of new growth taken in spring can be carefully removed with a sharp knife and potted up in a soil based compost with added grit.l At a later stage, one of the long trailing stems can be cut into pieces, each containing a node which is then potted up so that the node is just above the soil. They should be shaded from the sun and kept humid. (Has anyone tried layering???)
the result may not be true to type, on the other hand, there is the possibility of raising a new hybrid!
hardy geraniums propagation
Thank you, spider, for the write up. I have divided my HGs with good success and would like to try cuttings next.
What is your favorite rooting hormone? I have read that some cultivars will root better if they have a 'treatment'.
Also, are you familiar with starting HG cuttings in 'oasis'? I saw some notes on this method but I am a newbie on propagation and basically am clueless.
Thanks so much. t.
I use Rootone (when I use any). most of the time I don't bother. Whe you have the chance, try root cuttings. You will get many plants from small roots. It is worth it.
Thanks Anna! I just had to punt when I dug mine up last month. It was about 5' x 4' (all started from a 4" pot) the whole thing had to go, but I kept one handful and so far so good! Wish I had the energy at that time to divide the whole mass. I would have had starts for all of Daves! LOL
thanks for the info!
In my zone of 9b, this is not Zonal geranium season, way too wet. I picked up some at a big box store on clearance and want to propagate for the drier fall season. I read spider's posting of the different types, however I'm not sure of the best method for zonals and I don't understand root division. I really hope you can advise. Thanks, Pat
Patsum, there is a thread about this type of geraniums (zonals) in a thread by beaker called propagating advice on the 8th of july.
You don't divide zonals only hardy ones. with zonals you do just cuttings. Read the thread and, if you have any questions, ask away.
thanks spider, found it, read it, try it tomorrow. But what is Messenger??? Also you mentioned having the cuttings at a constant temp. Here in Florida, it is constant humidity, but temps go from over night of 75 to day time of 93. My house is very dry (main purpose of the a/c). Which would be the better location?
Messenger is a plant hormone that is mixed with water and sprayed on the leaves of plants. Some peeps swear by it. I think there is a thread about is somewhere.
The geraniums do better with a constant bottom temperature so I woulld put them on top of the refrigerator where it is warm. But it is not important at this time of the year. The will root easily, I use 1/2 perlite, 1/2 potting compost. They need to be kept on the drier side. Water them well when you pot them and leave the compost to dry before you water again.
you don't need to cover the cuttings with a plastic bag nor spray them with water.
I wanted to add this pictorial link from the RHS about propagating using roots as suggested by Spider for Hardy Geraniums.
I am going to try some root cuttings this fall.
And google-ing around I found Chiltern's list of Hardy Geranium seeds for sale.
Quite a range available, and while they may not be available to US customers (I haven't checked lately) , the descriptions are useful.
I have trouble keeping all the cultivars apart and I know some are easier to grow in our climate than others.
I've had very good luck with seed propagation. In the case of Midnight Reiter or Purple Haze (G. pratense), the dark leaves are not present in all the offspring, but perhaps half. Some varieties will germinate under lights at about 60-70 F, but others benefit from winter sowing. Whatever method, most all should be pricked from the starter medium, and the rest left to germinate with time. I've seen seeds germinate and new plants pop up a month or more later. Here are some of the varieties I have propagated from seed:
G. pratense mix
G. pratense alba
G. pratense 'Rose Queen'
G. pratense var striatum 'Splish Splash'
G. pratense 'Purple Haze'
G. pratense 'Mrs. Kendall Clarke'
G. x oxonianum 'Claridge Druce'
G. pratense 'Midnight Reiter'
G. bohemicum 'Orchid Blue'
G. pyrenaicum blue
G. pyrenaicum alba
G. x oxonianum
G. yoshinoi 'Confetti'
I've traded, collected or purchased seeds for all of these. I got some wonderful seeds from Psilo when she still had her seed site on the Web. I've ordered from Chilterns, as well.