GERMINATION EXPERIMENTS

Even before I established Chadwell Seeds in 1984, it was important for me to check that the seed I was supplying exhibited high levels of viability.  I have thus regularly sown seed at what became the Kohli Himalayan Botanical Garden in the UK for more than 30 years and took an interest in how others got on with my seed (from various sources) by extensive correspondence (now mostly, though, not exclusively, conducted by e-mail).  My lecturing around the UK along with lecture tours in North America and New Zealand, combined with visits to other countries has provided me the opportunity to be shown round numerous private gardens including those growing my seed and "behind-the-scenes" at famous ones open to the public - which has meant that I have accumulated unrivalled knowledge about the initial germination and subsequent cultivation of Himalayan flora. It is satisfying to be shown a plant raised from seed supplied by me - particularly those introduced decades ago. It typically takes several years for plants to reach flowering size from seed sowing, at times, such as for some shrubs or trees, a decade or more.  So one has to exhibit patience, when raising more unusual plants from seed, which has not been bred for speed or consistency of germination.

Chris Chadwell in the rear section of the Kohli Memorial Garden, re-potting a clump of Hedychium seedlings a few years ago © Joseph Chadwell


Germination Results  I have sown all items from the Himalayan Plant Association 2018 Seed Exchange (2017 harvested seed) and the 2018 Chadwell Seeds Catalogue.  Will be showing images during the year as to what happened in reverse chronological order:

22nd July 2018 - 'West Himalayan Blue-poppy' (Meconopsis aculeata)


Much to my surprise, I spotted what was obviously a stray seedling of Meconopsis in one of the pots! It had to be from one of two sowings of Meconopsis aculeata HPA 1380 or 1381 (I had not sown seed of any other Meconopsis for years).  The 'proper' sowings were made on the surface of moist compost inside polythene bags but these failed - perhaps just sowing like with most other seed, though the covering of grit should be thin. I shall try this next time. It also just goes to shown that despite the sower's best intentions, seed can end up where it was not intended.  Over the years, I have received some aggressive letters or e-mails telling me off for sending a grower the wrong seed e.g. a packet of Himalayan seed which turned out to be of a different genus from another part of the world; in every case it turned out that the grower already had the plant growing in their garden which they accused me of falsely sending to them.  I, in every case, had never ever had such species from any source!  Likewise, beware of seed arriving in pots on the wind or dispersed by birds from surrounding gardens or native plants. Another typical mistake is labelling errors - we all make these occasionally.  Anyone thinking they never do, is mistaken....© Chris Chadwell 

Another consideration, for rather more genera than is realised, is the potential for hybridisation once a plant is in cultivation.  Meconopsis are certainly prone to crossing; I have grown a what were obviously hybrids from various cultivated sources. Whilst I cannot be absolutely certain, this seedling does seem to match well my current understanding of Meconopsis aculeata. Whether I can succeed in coaxing it into flowering remains to be seen - our hot, dry summer is not conducive.  If my memory is correct, the last time I managed to flower this species was a delightful dark pink variant originally flowered by the late Martin Carter, then a HPA member living in Scotland; the timing was near perfect (its flowers were just starting to go over) as BBC Gardeners' World were filming (see: https://sites.google.com/a/shpa.org.uk/main/bbc-gardeners-world-filming-kohli-memorial-garden) - by chance, another, much taller Meconopsis was also in flower:the blood-red  M.staintonii (although at that time, I was uncertain as to its identity). © Chris Chadwell 
20th June 2018 - Bergenia stracheyi

Bergenia stracheyi - mass of seedlings. Its seed is fine. In the wild often forms patches on open, sunny rocks. Has proven more fussy in cultivation than the other common Bergenia, B.pacumbis (syn. B.ciliata forma ligulata), surprising as the latter hails from lower-elevation, shaded, moist places. © Chris Chadwell 

Bergenia stracheyi - close up of seedlings  © Chris Chadwell 

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19th June 2018 - a surfeit of cobra-lilies (Arisaemas)

Arisaema costatum HPA 1363 © Chris Chadwell 

Arisaema intermedium HPA 1365 © Chris Chadwell 

Arisaema propinquum P.Kohli & Co. 2016 harvested seed © Chris Chadwell 

Arisaema tortuosum sown 7/4/17, small corms over-wintered outdoors, healthy re-growth this spring © Chris Chadwell 

Arisaema tortuosum sown 7/4/17, small corms over-wintered outdoors, re-growth this spring slower than pot above © Chris Chadwell 

Arisaema consanguineum sown 7/4/17, small corms over-wintered outdoors © Chris Chadwell 

Arisaema consanguineum sown 7/4/17, small corms over-wintered outdoors © Chris Chadwell 

Arisaema flavum © Chris Chadwell 

Can you recognise the different species of Arisaema? © Chris Chadwell 

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28th May 2018 - Salvia nubicola & Rheum sp.

Salvia nubicola HPA 1388 - cotyledons and first true leaves © Chris Chadwell 

Rheum sp.HPA 1385 - cotyledons and first true leaves with long petioles © Chris Chadwell 

Rheum sp.HPA 1385 - cotyledons and first true leaves with long petioles © Chris Chadwell 
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12th May 2018 - clumped seedlings progressing nicely; transplanted specimens from front section of garden; stray seedling

Assorted pots with seedlings growing in clumps which have been re-potted, keeping clump undisturbed (as much as possible).  © Chris Chadwell 

Assorted pots with seedlings growing in clumps which have been re-potted, keeping clump undisturbed (as much as possible).  © Chris Chadwell


Assorted pots with seedlings which have sprouted since sowing in April.  © Chris Chadwell

Three specimens transplanted from front section of garden: Deutzia staminea; Inula racemosa; Paeonia emodi - whilst two had grown satisfactorily (and flowered), the exposed, sunny position was probably not ideal, so will experiment with them in a lightly shaded, better-watered spot in the rear section of the garden.  © Chris Chadwell

Vigorous, large cotyledons of Rheum sp. - over the decades I have found that members of this genus almost always are amongst the quickest to germinate and then grown on vigorously.  I have flowered two species (one on several occasions) but never got them to set-seed - though this is possible in cultivation because one of them, Rheum tibeticum was obtained through the Berlin Botanic Garden Index Seminum.

Arisaema consanguineum with its immature, first-year true leaves, doing well in a clump.  © Chris Chadwell

Two seedlings in this pot (disappointing initial germination).  The bottom seedling is the true Potentilla cuneata, however, the much larger one at the top, is clearly a Geranium.  It is easy for growers unfamiliar with genera as seedlings, particularly Himalayan species, to think the stray seedling was what was sown, especially if none of the genuine seed had sprouted at that point. When you only get a few seedlings (one or more), especially if you sowed a much larger number, then be suspicious.  I knew I needed to remove the 'stray', which was clearly vigorous - its root system could soon harm the remaining seed, the longer it grew, the more potential harm.  © Chris Chadwell

The removed Geranium, which has a large, thick rhizome, typical of G.wallichianum - which is utilised in Tibetan Medicine.  © Chris Chadwell


4th May 2018 - stray 'weed' seedlings, re-potting in clumps, adding horticultural sand to discourage mould

Three seedlings in a pot sown last year with Anaphalis seed but no germination that year; no sign of germination yet this year - growers must always take care not to mistake stray weed seedlings for what should be growing in the pot!  One useful trick is to know whether the seed sown is of a dicotyledon or a monocotyledon - IF what sprouts in the pot is the opposite, then clearly it is a stray, so one does not have to wait before removing them (if allowed to grow too large, their root systems can create problems when removed) - and one does not have weeks (or months) of false expectations.  Even if the grower is very particular about hygiene with pots, compost and sowing, seed can be brought in on the wind or dropped by birds.  Recognising the seedlings of common weeds growing in your garden or trees in neighbours' gardens is helpful.  The two seedlings c. centre and to left (or is it one) looks like an Epilobium to me, which has fine seed which is dispersed on the wind - not sure, at this stage, what the other is but definitely not an Anaphalis - so they will be disposed of!

Seedlings (with cotyledons) of Gentiana sp. with polythene bag removed temporarily - they look fine but mould is developing in a few places.  Pity to lose them after such a promising start, so decided to add from horticultural sand to aid discouraging the fungus. © Chris Chadwell

Seedlings (with cotyledons) of Gentiana sp. with polythene bag removed temporarily - with horticultural sand added to aid discouraging the fungus.     © Chris Chadwell

Clump of Arisaema consanguineum progressing well © Chris Chadwell

Larger pot ready for transplanting of Cephalaria  seedlings (with cotyledons only but already large) containing sufficient compost to allow the seedlings to be place inside intact - then more compost would be poured into the gaps and firmed in. © Chris Chadwell

Larger pot  1/4 to 1/3 full of compost prior to transplanting - sufficient to keep seedlings I their 'clump' © Chris Chadwell

Clump of Cephalaria seedlings showing roots, kept in their clump as much as possible prior to transplanting © Chris Chadwell

Healthy roots of Cephalaria seedlings; although the true leaves not developed yet, one can see that they would soon have become pot-bound (just weeks after seed was sown) - research suggests square pots are better than circular ones in terms of root development but I do not have any larger square pots (all my large ones were kindly donated and every penny saved when on such a tight budget as mine, helps) © Chris Chadwell

Cephalaria seedlings kept in clump after transplanting - with minimum disturbance, the individual seedlings will be 'nursed' collectively.  Beware, I often plant out in clumps as well!  My poor RHS, Wisley-trained late Uncle Douglas Chalk, NDH, horticultural adviser and nurseryman would be turning in his grave as I completely disregard the 'rules' about pricking out seedlings! It works well for most plants, though not ideal for those with hairy foliage prone-to-botrytis.  Not having to prick-out often appeals!  © Chris Chadwell

Seedlings of Vincetoxicum hirundinaria ready for transplanting © Chris Chadwell

Roots of Vincetoxicum hirundinaria - clearly ready for transplanting © Chris Chadwell

1st May 2018 - a bumper haul of 6 different pots showing first signs of germinations

Cotyledons of Rheum aff. australe HPA 1385 some with empty seed cases still present - sown 1st April; previous experience shows that Rheum seed is often amongst the quickest to sprout, sometimes in just days, mostly 2-4 weeks, exhibiting excellent viability. What a pity that despite having had Rheum tibeticum flowering in the front section of the Kohli Memorial Garden for many years, it has never produced viable seed and that same has happened for a couple of years with the Rheum in the rear section of the garden. © Chris Chadwell

Cotyledons of Rheum aff. australe HPA 1385 - the seedlings will soon be bursting to escape the confines of the pot!  © Chris Chadwell

Cotyledons of Cephalaria gigantea (syn. Scabiosa gigantea) - the seedlings will also soon be bursting to escape the confines of the pot!  © Chris Chadwell

Small cotyledons of Gentiana - the four much larger seedlings (with both linear cotyledon and true leaves) are of stray weeds; I neglected to surface sterilise [with boiling water] the surface of the compost prior to the seed being sown on the surface but not covered, as seed of this genus often have a light requirement for germination; the compost had been moistened by keeping in a bowl of water, then placed in a sealable A4-sized polythene bag but the problem with doing nothing else is that stray weed seeds sprout, which some may initially mistake for the actual seed sown, then algae, moss and lichen can grow or mould develop, eventually smothering to legitimate seedlings. © Chris Chadwell

The weed seedlings removed before they can create problems © Chris Chadwell

The gentian seedlings, free to develop but other problems will have to be faced. I have always struggled with Gentiana seed and when I manage to get the seed to germinate, the seedlings have never come even close to flowering!  Perhaps it is our chlorinated tap-water.  Impractical in the small garden to have a rain-water container to take the run-off from the garage roof - just not enough space.  Any suggestions, as would be delighted to finally flower a gentian!  At least this image illustrates the viability of the seed © Chris Chadwell

Seed of an unidentified gentian starting to sprout but unfortunately mould also has developed; some horticultural sand has been added to try and hold this back; note the polythene back has been opened for inspection (with the back sealed, no watering in required) © Chris Chadwell

Closer view of pot above with seed of an unidentified gentian starting to sprout but unfortunately mould also has developed; horticultural sand has been added to try and hold this back; note the polythene back has been opened for inspection (with the bag is sealed, no watering is required) 

© Chris Chadwell

Seelings just appearing (sown a month earlier on 1st April) of Allium wallichii HPA 1360 -  note the empty black seed coats still attached to some

  © Chris Chadwell

Seelings just appearing (sown a month earlier on 1st April) of Allium wallichii HPA 1360 -  note the empty black seed coats still attached to some

  © Chris Chadwell
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Germinations during April 2018

Codonopsis vinciflora seedlings sown 1/4/18 germinated en masse 3 weeks later © Chris Chadwell


Arisaema consanguineum sown April 2017, germinating promptly; re-emerging with true leaves this year, rather than cotyledons © Chris Chadwell

Rosa brunonii seedlings sown 7/4/17 germinated a year later © Chris Chadwell
























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