More About the Red Rhododendrons in California
By L. C. Living, Vancouver, B.C.
Everyone is entitled to their likes and dislikes with regards to plants but with serious growers of rhododendrons there seems to be a pattern which is often followed. This seems to start with hardy hybrids, move into the modern hybrids which are not always hardy but present a challenge, and finish with the species.
Because they are gaudy, produce masses of bloom with great regularity and are hardy, the hardy hybrids usually are the first to be planted in the garden. Originally the breeding of these was done in several English nurseries but a large percentage of the ones now being sold were the work of the Dutch Nurserymen around Boskoop. These with only small areas of land had to raise plants that were hardy enough for their climate. Also because of the lack of room to grow a plant on, the propagations had to be saleable when small and therefore had to bud up quickly. Quite obviously, if a plant took a number of years to start flowering, its commercial possibilities were considerably reduced and regardless of how beautiful the flowers might be the plant would have to be discarded.
The modern English hybrids on the other hand were the products of large privately owned estates most of which were in areas where the more tender species could be grown. It was the owners of these estates who financed the collectors who were to send back the seed of the new species. They grew the seedlings in such quantities that they often had to take over grazing fields. It was only natural that the best of the new species should be used as parents and even if many of the resulting hybrids are not worth garden space there are some that are outstanding. These hybrids were made for the pleasure of an individual, not for propagation for the masses. Whereas the Dutch have maybe six species in their hybrids, the named plants being the result of careful selection, the number of species in the English hybrids are numbered by the dozen.
Most of the red species, of which R. arboreum was the most important, it being the earliest known, are tender. To have a garden plant with anything approaching its fiery red flowers necessitated its being crossed with something very hardy. The species R. catawbiense with its rather unattractive pinkish-blue flowers, was one of those used. It is also late flowering and this helped offset the earliness of R. arboreum. But as a garden plant R. catawbiense is useless, as a parent it has its uses. Even after many generations of crossing no red hardy hybrid has been able to rid itself of this blue tint so that anyone who says that they are pure red is color-blind. Some of them come close to it but never do they approach the pure colors of the English hybrids.
Take a flower of R. 'Earl of Athlone' and put it in a truss of R. 'David' and it stands out like a sore thumb. Both are described as being 'Blood Red' but the latter is a pure color while the former is shaded blue. Fortunately we can grow both of these in our climate.
R. 'Queen Wilhelmina' is seldom seen, a scarlet that fades to a rosy pink. It is excellent in a mild district. It is also the parent of several red hybrids including R. 'Earl of Athlone', R. 'Langley Park', R. 'Unknown Warrior', and R. 'Britannia'. This latter is the most popular of all the reds. A low growing hybrid with sickly yellow green foliage, and fast fading flowers has everything a nurseryman desires. The flowers are big and frilly, the bush buds when small, and the flowers open during the main sales period. But these flowers are not a pure red. They are not to be compared with the English hybrid, R. 'Leo', the cross between R. 'Britannia' and R. elliottii. The flower color has improved, the foliage looks like a healthy plant, the hybrid is taller and less formal. It is outstanding but the infusion of the tender species has made a hybrid that up here we may not be able to grow.
This is only one instance of where a hardy hybrid has been improved by crossing it with one of the new tender red species. Another is R. 'Moser's Maroon'. The beauty of this plant lies not in the flowers - they are too dark and they must have a location where the light shines through them, but in the new growth. This is bright red and in our cold climate makes up for our inability to grow Pieris forrestii. R. 'Moser's Maroon' is the parent of several excellent hybrids all of which are superior to it. The flowers of R. 'Romany Chal' are excellent and their intensity is retained for a long time, the habit of the bush is untidy but no worse than either parent. R. 'Romany Chal' is magnificent with huge round trusses of scarlet flowers. R. 'Grenadier' is the cross with R. elliottii and as with R. 'Leo' has changed its hardy parent into a small tree. With R. 'Grenadier' the big full trusses of blood red flowers are in perfect proportion to the long dark green foliage. When R. 'Moser's Maroon' was crossed with R. arboreum the result was the early flowering R. 'Bibiani'.
This rhododendron is one of an early group that we can grow provided we are prepared to protect the flowers from spring frosts or not have a regular display. In California this is no problem. The result is the English hybrids have extended the safe flowering period by several months. Here any rhododendron that flowers before mid April risks being cut by frosts. R. 'Bibiani' is one of these.
R. 'Portia' is another. Excellent crimson flowers of waxy texture in a compact flat topped truss. Each flower is 2 inches across. From R. strigillosum it inherits its tidy rounded habit. its long narrow foliage covered with noticeable brown hairs. R. euchaites has made it later flowering but not late enough for us.
R. 'Choremia' is another but it is quite probable it is not offered by nurserymen.
R. 'Shilsonii' is the cross between R. barbatum and R. thomsonii. Both these species are early flowering, are small trees, are hardy, and are red. The hybrid is not outstanding but is not out of place in a garden. When crossed with R. arboreum the result was the utterly magnificent early flowering R. 'Cornubia', a plant which should be in every garden where there are no frosts after February. With two hardy parents it is possible that we up here could winter it, but not until this year did a local gardener have the courage to try one. It takes a number of years to start flowering-a characteristic of all these Modern Hybrids, the habit is upright and open, the foliage is excellent and the flowers are intense scarlet in big trusses.
What hardy hybrid can compare with R. 'Barclayi'? This is probably the ultimate of perfection. Perfect habit, upright and open and tree-like, but never untidy. The flowers are in immense un-crowded flat trusses-as are both the species R. thomsonii and R. griffithianum, and can vary from crimson to scarlet to blood-red-showing the influence of R. thomsonii and R. arboreum, depending on the variety. The foliage is rounded and blue green-again the R. thomsonii, and is in perfect proportion to the huge truss. It is early flowering, mid-April usually finds it out, and with R. arboreum and R. griffithianum as parents it is too tender for us. In Eugene it is magnificent, further north it just exists, a shadow of the glorious plant it can be.
Naturally it was used as a parent and with one exception none of the progeny equal it. That one is R. 'Kiev' the cross with R. elliottii. This may in time, when big plants have had time to develop outrival its parent. The flowers are slightly larger and slightly darker, made more so by the distinct dark spotting in the nectaries. The truss of 8 flowers is sufficient and as with all R. elliottii hybrids the foliage is excellent. Another cross is R. 'Laura Aberconway' but this in comparison is a poor thing with untidy habit and less showy flowers. At least we can grow it in Vancouver.
All these have been criticized as being woodland plants growing well only where they can get broken shade such as is given in the California fog belt. This is the reputation they got by being developed in gardens with just those conditions. Time has shown that they grow as well in the small garden as on the big estate. Even the color of the hardy hybrids will fade fast if they are in full sun. R. 'Mary Jean' for example opens an excellent color but it lasts only a day or two unless in the shade.
If it had not been for the interest the British amateur had in plants of all kinds it is very likely that none of the new rhododendron species would ever have been found. If it had been left to the Dutch nurserymen it is quite certain we would never have seen them. The fact that most of the hybrids they raised from those new species are pure junk is natural but given time more excellent ones will appear-ones that we can grow in Vancouver without having to worry about earliness or hardiness. In the meantime we will go on envying those in California who can grow anything if they have the eyes to see that a flower to be beautiful does not have to be blatant.