This blog reviews the latest products, plants and innovations in gardening. It also provides a link for my many gardening friends who are members of the GardenMessenger and Seedmessenger Yahoo groups and their sub-groups that I moderate.

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Location: Australia

I am a semi-retired UK botanical garden curator and former international horticultural consultant, who has worked extensively in Europe, the Middle East, North America and Australia. I spend part of the year in Australia and part in Europe, mainly due to family and work commitments. I earn my living from writing and editing Internet copy, articles and books. I have written over fifty books on gardening and have been translated into twenty-four different languages. I am a former UK Garden Writer of the Year and a previous Quill & Trowel Award Winner from the Garden Writer’s Association of America. I am interested in developing gardening communities on the Internet and I manage the popular GardenMessenger Yahoo group, along with its various sub-groups like PondMessenger and SeedMessenger. I also edit International Water Gardener and its associated regional web-sites.

Thursday, April 13, 2006

Sweet Pea Germination, New Astilbes and Happy New Year!

Sweet Pea 'Early Fragrance'

It is great to know that although this blog is very new there are one or two folks out there reading it, mostly friends from the GardenMessenger Yahoo group that I moderate. One old cyber gardening friend, who I have never met but I feel I know well, is Fred, an enthusiastic and on his own admission, not very green-fingered amateur. He has almost given up on raising sweet peas this year as he cannot get them to germinate. At least he gets a few to come through, but not enough for the row along his fence that he has planned for. He wants about fifty seeds to all germinate at once and to grow evenly in order to produce a good display.

As most gardeners know sweet pea seeds can be a bit tricky to get started. Most commercial sweet pea seeds are produced in climates that are very warm at seed ripening time. This causes the seed coat to dry and tighten, often closing the tiny micropyle or hole through which the seed absorbs moisture once planted. It is the absorption of moisture that triggers the germination process. Traditionally gardeners have carefully chipped the seed coat of each seed in order to permit moisture to be absorbed. This is a long and tedious process, and if not carried out correctly often leads to the seeds rotting rather than germinating. Poor old Fred. He said that it took him over an hour to chip his seeds and when he went to investigate why the majority had not germinated three weeks later, they were mostly in an advanced state of decay. Thus his cry for help.

Well I hope that I can help Fred and others who find sweet peas difficult to germinate. There is a little time-saving and effective trick that I came upon completely by accident. A few years ago I was attending a lecture about tropical legumes at the Linnean Society of London. The Linnean Society is a very august body and most of its discussions surrounding plants are not immediately of practical value to the gardener. This lecture was a revelation, for it focused upon the arid land species of Acacia that were being used in some Third World communities to fight desertification. The seeds of some of the species being used had the same problem as their cousin - the sweet pea. A dry tight seed coat that required chipping in order to permit the entry of moisture and therefore germination.

In their quest to find a solution, the scientists involved with the project had examined the seeds under a microscope. To their surprised they found that in the scarred area around that part of the seed where it had been attached to the funicle - the structure that secured it to the pod - there was a faint crazed area of the seed coat. They wondered if they enhanced this crazing if the seeds would then be able to absorb moisture and start the germination process without the tedium of chipping. Using laboratory shakers they eventually came upon a period of time and rate of shaking that enhanced the crazing, without skinning the seeds completely. The need for chipping was totally eliminated.

Excitedly I went home to try the experiment on sweet peas, for at that time one of my responsibilities was the overseeing of sweet pea trials. Could I save the trials officer and his staff hours of tedium. I used a hand lens and could not detect any crazing of the seed coat, but then I did not have the benefit of an electron microscope and I recalled that the lecturer did say slight crazing. So I experimented with standard packet sweet pea seeds and a Nescafe instant coffee jar. After several abortive attempts, when few seeds germinated after treatment, or I managed to skin them completely after excessive shaking, I came upon a practical formula. Using around 50 seeds in a medium sized coffee jar (with the lid on!) and shaking them for two minutes I discovered that chipping was no long needed. In practical terms this meant counting steadily to 120 and shaking the jar rhythmically. What a time saver! Since then I have never chipped a sweet pea seed. However, my wife Hazel always insists that I conduct such activity in private, less it be thought that I am losing my senses.

Astilbe 'Color Flash'

Although many new plant introductions take a while to spread around the world, I always like to get a preview when I can, even if I may not be able to obtain them for a while. One recent introduction, which won a silver medal award at the famous Plantarium exhibition in Holland, and looks an especially useful and versatile plant, is Astilbe ‘Color Flash’. The soft pink mid to late summer blossoms are produced in neat spires above foliage that emerges bright green and matures to rich burgundy. A very hardy plant that will be great for a moist border or the bog garden. It can also be grown successfully in a pot or container, providing that it is kept very well watered. It appears to be quite widely available this season both in Europe and North America. The more recent introduction ‘Color Flash Lime’, which I have yet to see, looks equally useful, but with light green foliage which intensifies to yellow as the summer progresses. It too has pink flowers, and I guess having such bright yellow foliage will benefit from a bit of shade to prevent the leaves browning at the edges. It is available in North America, but I have not heard of it being so elsewhere.

Finally, a Happy New Year to the Thai members of GardenMessenger and its associated groups, also to any visitors to this blog from Thailand, Cambodia, Laos or Myanmar. I wish you a happy Songkran. New Year’s greetings also go to my friends in Sri Lanka who are celebrating the Sinhalese and Tamil New Year today.

Happy Gardening



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Photos: Suttons Seeds
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Blogger cockyfarmer said...

Hi all. Thanks for this blog. I am Garry from Australian Gardeners Group. Just a thought on sweet peas and aid to germination I have also had recommended that you rub the seed on a sandpaper plate

12:36 pm  
Blogger Mary Jo said...

Thanks Philip for the info on Sweet Peas. I too had no luck getting them all to geminate...will try your idea!

5:23 pm  

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