Dr Christopher North’s hybridising work with lilies 

Peter Waister gives an insight into Dr North’s career in horticulture and the outstanding contribution he has made thanks to his hybridising work with lilies. 

It was a lucky chance that led Dr Chris North to initiate the programme that produced the North hybrids.  It might have been a series of cabbages instead!  In 1996 he was Head of the Plant Breeding Department at the then Scottish Horticultural Research Institute, and was directing a team whose target was to produce soft fruit and vegetable cultivars adapted to the Scottish climate.  This was the team that produced such notable cultivars as ‘Celtic’ cabbage, the Glen series of raspberries and the Ben series of blackcurrants.  However, the programme had grown to a stage where much of Chris’s work had become administrative and he was missing hands-on plant breeding.  He mentioned this to the then director Dr Colin Cadman who, knowing that Chris had made some lily crosses in his garden, suggested he should go ahead with a small programme.  At that time the efforts of agricultural and horticultural research institutes in Britain were directed almost exclusively towards food production, and a flower breeding programme would be unlikely to attract support.  It could only be accommodated if it were low key, if not invisible!  It is a measure of the ultimate success of Chris’s work that the North lilies were later to be hailed as one of the achievements of the Agricultural Research Council’s programme.

The original aim of the programme was to produce lily cultivars adapted to British conditions, particularly for the north of the country.  Specifically the objectives were freedom from disease, vigour and the ability to stand without staking.  Elegance of form and unusual colours were also given prominence.  The emphasis was on garden characteristics rather than suitability for the florist, which is the more common aim in modern lily breeding.

Starting with varieties and species from the asiatic group, a large number of crosses were made, fro which were produced in 1974 the varieties ‘Orestes’, ‘Minos’ and ‘Phoebus’, followed a little later by ‘Achilles’ and ‘Pandora’. 

The Lankongense hybrids 

In the next stage the species Lilium lankongense was used as a parent.  It differed from the other asiatics in being a true pink and had been suggested as a possible parent by Jan de Graaf.  However no one previously had succeeded in producing hybrids from it.  The first attempts resulted in a limited amount of capsule swelling but the seeds produced were not viable in soil, hence the adoption of embryo culture, which was at that time a relatively new technique. 

Crosses between L. lankongense and asiatic species and hybrids gave rise to the cultivars ‘Ariadne’ and ‘Adonis’, the latter being awarded the Reginald Cory Memorial Cup.  These were the first of the L. lankongense types that became known as the Greek series, since they were named after Greek gods.  (Chris had been dissuaded from using names with a “tartan image”, just after returning from holiday in Crete.) 

By backcrossing these to other cultivars, again using embryo culture, Chris obtained ‘Theseus’, ‘Eros’ and ‘Pan’.

These three hybrids were sterile and, in order to try to regain fertility, they were treated with colchicine to double the chromosome number.  Most lilies have 24 chromosomes but, to Chris’s great surprise, a count of the doubled material showed 72 chromosomes, disclosing that the three hybrids were triploid not diploid.  This may explain their vigour since it is known that this is a characteristic of other sterile triploid lilies such as L. lancifolium.  (‘Ariadne’ and ‘Adonis’ were diploid but sterile.)  The hexaploid material was not exploited, as it arose at the end of the breeding programme. 

A second wave of over 300 hybrids was obtained by backcrossing the first to asiatic hybrids.  This was a larger scale programme than the original, which had been limited by the low number of embryos obtained.  In the second round, glasshouse temperatures and humidity were raised during fertilisation and many more embryos were obtained that survived when transferred from sterile tubes to soil and grown on under mist propagation.  When the programme was terminated at the Scottish Horticultural Research Institute in 1978, ten numbered lines were sold to the Lily Group.  This series has come to be known as the “North Ladies”.  Chris had picked one line that he wanted named for Marie, his wife, and suggested that the other nine should be named after other female relatives.  He provided the names, and the Lily Group made the allocation of these names. 

As mentioned earlier, the breeding objectives excluded suitability for forcing or for the cut flower trade.  Relieved of these constraints it was easier to select for garden performance. 

At the end of the programme, unnamed material was sold to the Lily Group under numbers. 

Hybrids of other species                     

Two smaller lines of research involved L. pyrenaicum , and L. henryi, and both yielded interesting hybrids.  Chris has a particular liking for a cross between L. pyrenaicum and L. pomponium, because it so nearly matches the original objective, to create sturdy, garden worthy plants of good form and colour.  It has beautiful narrow dark green leaves, attractively bordered with silvery-white, and flowers of a strong red.  It will grow in grass, so appears to have inherited the constitution of L. pyrenaicum, which is the only lily species that survives in hedgerows as a garden escape in Scotland.  The bulbs of this hybrid grow to a remarkable size, as large as a swede turnip.  It was originally proposed that it should be named ‘Europa’ but the name was already used and Mrs Dee Simmons suggested “Chris North”. 

Towards the end of the lily breeding work an attempt was made to take advantage of the expertise acquired in embryo culture to make a cross between Lilium henryi and an asiatic hybrid.  Previous breeding work with this species gave rise to the aurelian hybrids, involving crosses with L. sargentiae, and ‘Black Beauty’, derived from crosses with the oriental group.

A hybrid was raised, the first record of a successful cross between L. henryi and an asiatic cultivar.  Though it grew and flowered well, Chris did not consider it to be up to the standard of the lankongense hybrids and it was not named.  Bulbs were made available to members of the Lily Group as possible breeding material. 

Wider interests 

The main lifetime interest of Chris was the humble brassica oleracea, in the form of cabbages and brussels sprouts.  As a student of horticulture before the war his journey from home in Birmingham to university in Reading took him through acres of ’January King’ cabbages, which seemed to him at the time to represent a most boring aspect of horticulture.  After the war when working at The National Institute of Agricultural Botany in Cambridge he realised that this cabbage was, at that period, probably the most important vegetable crop in Britain but it lacked uniformity and a considerable proportion of the plants never produced marketable heads.  He decided to produce a uniform F1 variety, which was the new thinking to solve this problem at the time.  An appointment at The Scottish Horticultural Research Institute (now the Scottish Crop Research Institute) in 1953 gave this opportunity and under his guidance ‘Celtic’ cabbage was bred, the first F1 brassica produced in Britain and still grown 35 years later. 

Chris North has a passion for a wide variety of garden plants in addition to lilies, and has become an expert on the Mediterranean flora, after many years of travel there with his wife, Marie. Sadly, Marie died in December 2003. She and Chris had met when they were both in the Royal Air Force during the war, and they had 56 happy years together. 

He gardens in a narrow valley (“den” in Scotland) through which flows a stream that leads ultimately to the river Tay.  His house is a former mill, one of 13 that were powered by this one stream.  One of his first acts in going there was to harness the stream with a homemade turbine to provide electricity for his house.  The diverting of the stream through the turbine incidentally gave better control of the flow so plants on the banks were not lost through flash floods.

The one-acre garden is all on a slope, on mostly very shallow soil, in a frost pocket, so presenting a challenge in selecting suitable plants. The choice was much influenced by a desire to have plants that are decorative over a long period, either because of a long flowering period or good foliage, preferably both.  Many Scottish gardens are designed to be at their best in spring and early summer, but Chris’s garden has many late flowering species, and a concentration on foliage of good form and colour. The lily ‘Chris North’ meets this foliage and form target very well.

If there is one group of plants other than lilies that have provided particular fascination for Chris, it is hardy orchids, even though they are not long-lived in eastern Scotland.  His present special success is with Cypripedium tibeticum.

Records of the lily breeding at SCRI and of plants encountered in 25 years of Mediterranean trips, and of his garden plants, have been put on CDs.  Chris embraced this new technology with enthusiasm, not for its own sake (he has frequent arguments with his computer) but because of the opportunities it gave him to present information and pictures of the plants he enthuses about.  The CDs are available from Chris to those who would like them.

Though he has now been retired for 26 years he still feels he has some unfinished business in lily breeding and recently acquired some colchicine with a view to a new line of work.  Among the early hybrids was one ‘Ariadne’, that proved to be a diploid.  Here was an opportunity to double the chromosomes in the hope of obtaining fertile tetraploid.  Watch this space!    

 * Note – This article originally appeared in the RHS Lily Group’s publication Lilies and Related Plants 2003 - 2004, and is included on this website with the kind permission of the RHS Lily Group.