Kent Alpine Gardener's Diary
This entry: 10 February 2018 by Tim Ingram
Seeds of Change.
Seeds of Change
The most exciting of all aspects of gardening must be sowing seed. It is after all the ultimate basis of any green landscape, and for the gardener the opportunity to discover a huge diversity of plants. For the nurseryman it is a process above all which sets the pulse racing and heralds the spring.
We have always collected and sown a wide range of seed from plants in the garden, which give the best of all results because of the ability to sow freshly, or relatively soon after harvest, and experience the natural climatic cycle that seed has adapted to in the wild. A good number of early maturing seed of woodland plants and bulbs, sown in the summer and autumn, will germinate in the cool of a mild winter at a similar time that the parent plants come into growth. These are some examples gathered together for a talk on 'Sowing Seed' to the local Sandhurst Gardening Society last week.
Seeds of hellebores, sown quickly after collection in the summer, can begin germinating bfore Christmas - the three pots on the right of the above picture. Umbellifers - just left of centre is Ferula and Cachrys - usually appear soon after and in very early spring (and indeed can germinate in the fridge if obtained too late to sow naturally and kept at low temperatures for five or six weeks).
Many bulbs sown in the autumn are appearing strongly now. Some of those in the picture above are several years old and producing true leaves, left to mature bulbs before separating out. These two are a Brodiaea and Acis (Leucojum) autumnalis.
Others, such as Fritillaria thunbergii and Galanthus ikariae, sown last summer are germinating freely both in pots and, in the case of the snowdrop, in the garden.
This patch of G. ikariae has developed by seed over the past sixteen years with little disturbance until recently when bulbs have been lifted for sale, and shows how some snowdrops can increase and naturalise relatively slowly if left alone. Like many woodland species they are quite long term plants for the garden but we do intend to split these up and encourage more extensive spread in the future. Galanthus woronowii also increases well at the bulb rather than from seed and would be good to try and spread more widely. In other places we have picked nearly maturing seedheads of G. nivalis and 'sown' these extensively under a row of apple trees, with much more rapidly developed colonies of snowdrops flowering within three or four years.
Particularly exciting are the emerging seedlings of the 'Chilean Crocus', Tecophilaea cyanocrocus, from seed given to us by fellow Kent AGS member Peter Jacob, who grows the various forms of this extremely well in pots.
This scanned slide is of a plant grown by Jim Archibald amongst the stock plants he grew for his unparalleled seedlists.
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Various alpines are giving good results - these are Soldanella carpatica and Tiarella wherryi sown in June and July.
The seed mix we use varies but is generally based around John Innes Seed Compost and grit and/or perlite (up to 1/1), often with a loamless Sinclair Modular Seed Compost added (1/1/1). A loam based mix is much better for seed pots that may have to be retained sometimes for several years and for moisture and nutrient balance, but can be difficult to source in good quality now that John Innes composts are much less used commercially. For some more vulnerable plants - for example legumes which resent root disturbance and are prone to fungal attack - we are experimenting with a more sterile mix such as perlite and vermiculite, and there must be scope for more trials with different seed composts dependant on germination characteristics of different genera. Pots are normally top-dressed with a finer grade of chick grit or sieved Canterbury Spar (crushed flint).
Sources of wild collected seed rely on dedicated individuals who get to know landscapes well and travel widely. As we are working to rebuild the nursery and garden on a smaller scale than two or three decades ago, we are also obtaining seed once again from overseas collectors, and these are two examples - the Greek and Czech plantsmen and growers Eleftherios Dariotis and Aleksandr Naumenko.
These are seed fom rather different environments - the Mediterranean with its mild and wet winters and the much colder steppe climate of Kyrgystan - so will need rather different sowing conditions. We are contemplating again setting up an old refridgerator in the garage dedicated to storing and stratifying seed, which especially can be used for late sown and wild collected species.
The intricacies of sowing seed are amongst the most significant and important aspects of horticulture and conservation, as Carlos Magdalena has stressed in his compelling and absorbing book, 'The Plant Messiah', on bringing plants back from extinction at Kew Gardens. There is considerable and detailed information on commercially important plants - for example trees and shrubs - and in the scientific literature, but rather less collated and shared regularly by the specialist plant societies, and so this looks to be a good topic (along with propagation in general) to explore here in more detail in the future.