Harvesting Hardy Geranium Seed

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By John Beaulieu (Bowl-you)

If I’m going to post what I’m learning about hardy geraniums, I should start with first things first. I guess that means that we start with the geranium seed, specifically harvesting that seed. But, even before that, I should give a little personnel history. What I had found so interesting with gesneriads (African-violets, sinningia, streptocarpus, etc) for the 35 years that I was involved with them, was the fun of hybridizing and growing from seed. When I switched over from indoor plants to outdoor plants, I soon discovered that I could have the same fun with the hardy geraniums. Although I had a few geraniums in my garden since the mid 1980s, it was only around 2008 as I added new varieties, that I started getting hooked, and by 2009 I was addicted and started growing geraniums from seed.

Here I’m seen (in 2009) looking over Geranium pratense ‘Splish Splash’ to see how seed production is coming along. This is an interesting plant, and one of those purchases that really got me hooked! You can see in the photo below how ‘Splish Splash’ has the interesting splashes of colour, with no two flowers being the same.

Most gardeners are familiar with the elongated fruit of the hardy geranium. After all, it is this beak-like shape that is responsible for the hardy geraniums common name of ‘Cranesbill’. Fewer may be familiar with the interesting methods of seed ejection employed by the hardy geraniums. Not everyone may want to harvest seed and grow geraniums by that method, but it is not all that difficult and is a good way to increase your plants or to experiment in creating something new. Some of my photos have built in text, as they are from my slide presentations.

When hardy geranium seeds are ready for harvesting the column or ‘beak’ will turn brown, and in most cases the seeds (in the mericarps) will appear dark. Once dry enough the awns (of most common varieties) curl up, flinging the seeds out of the mericarps. I had a photo in my previous blog showing how you can snip the tip of the beaks to prevent the seed from ejecting. This is useful if you are going to be away from home at a time when special seed might be ready.

Not all varieties take on this candelabra look. In some species the whole awn and mericarp is ejected with the seed. Those commonly grown species that DO NOT retain the curled awns and mericarps include: G. macrorrhizum, G. x cantabrigiense, the phaeum group, the cinereum group, and the robertianum group.

In my central Ontario garden, the first geraniums to have seed ready are the phaeums, commonly referred to as ‘Mourning Widows’ or ‘Dusky Cranesbills’.

The ‘Mourning Widows’ were one of my first geraniums back in the 1980s. As I write this in early June, they are at their peak, and when we sit out in the garden we can hear the hum of the busy bees. The many varieties of the phaeum group that I now have are all bee magnets, and we get honey bees, bumblebees, mason bees and leaf cutter bees, to name a few of the many pollinators.

When the pollinators are doing their job, going from flower to flower, I wind up with quite a variety of colours in my seedlings.

With the phaeums, timing is important if I want to harvest seed, since there are no tell-tale candelabra shapes to watch for. Just before the seed ejects, the mericarps will stick out ever so slightly. This is the time to pick the seed, as it would not be long before the seed would be ejected.

I also grow Geranium rubescens from the Canary Island area. This plant is a biennial and it is not hardy here in Canada. Rubescens refers to the very red stem colour, and all the foliage does colour up well in the autumn. The plant is very much like a giant Herb Robert. Being a biennial, you must harvest seed to keep the variety going. There may be areas in the UK where G. rubescens (also known as G. yeoi) may over-winter and self seed itself. I’d love to hear of anyone’s experiences.

You can see how both mericarps (with seed) and awns leave the column without a trace!

When I have a lot of seed ready to harvest, I use my slide-projector stand as a handy table to work on in the garden. I use envelopes to put my ripe fruits in and label them all with only one variety in each envelope.

Once I feel that the seed is quite dry, I will store the envelopes in the refrigerator until I am ready to sow the seed. Most will be sown in-ground late in the fall, with some special seed perhaps winter-sown in pots. Non-hardy varieties may be sown indoors in late spring. All seed will need some processing to separate the seeds from the mericarps, a chore I usually save for a raining autumn day, but that is a topic for another blog.

• 11 Jun, 2013
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