| 2013 Buddleja CalendarOctober 2013
September 2013
August 2013
A wild collected plant with branched white panicles. |
Spidermites cause a distinctive pattern of white spots on the leaves. | At last, some hot weather. All Buddlejas are growing fast now, most are quite drought tolerant so are coping well without much rain, although it has now rained hard at the end of the month. Plants in pots, however, do need constant watering. It isn't without some risk, though, and the nasty little two-sptted spidermites are making an appearance. Less than a millimetre across and fast breeding they feed on the underside of leaves causing white spots to appear on the upper side as they eat the cell contents. Outdoor plants are usually cured when it rains as the spidermites hate moisture but glasshouse plants can really suffer as they are progressively weakened by the damage to their leaves. Misting plants in the greenhouse helps or you can buy predatory mites that eat and then outbreed the pest. Pesticides are practically useless as the mites mutate and evolve resistance so quickly. They have developed a taste for my Buddleja alternifolia seedlings. Incidentally, the seedlings are now producing only alternate leaves, so possibly aren't hybrids after all. It seems there is a juvenile stage in this species with toothed, opposite leaves | The B. alternifolia seedlings now have alternate leaves that look more like the species. |
On the subject of putative hybrids I have been growing a number of B. albiflora seedlings from an open pollination amidst dozens of B. davidii cultivars. My thanks to Andrew Bullock (The Lavender Garden) for the seeds. The plants are rather varied with different leaf types, varying stem pigmentation but all are deciduous and have round rather than sub-quadrangular stems, a distinguishing feature that separates B. albiflora from B. davidii. There are three hypotheses for the parentage: | This B. albiflora seedling may have flowers that resemble B. davidii but the corolla tube is hairy within. |
These plants are now flowering and in several the flowers at first appearance look more like B. davidii than B. albiflora, as the flowers are very pink and larger than the species. But closer examination shows that the corolla tube is slightly conical and full of hairs, both feature of B. albiflora. The scent is very light and unlike B. davidii. Are these plants examples of species variation or hybrids? The B. albiflora seedling (left) has flowers that look like B. davidii and rather unlike the species (right). |
The first Buddleja davidii (or a hybrid of it) to flower has been Thompson & Morgan's Colour Fountain Blue. A rather curious plant, this, and still less than 50cm tall. It has very small, narrow foliage but the flowers are bluish lilac and not blue and the claim for the longest panicles is a bit far-fetched. This plant is an off-shoot of Charles Valin's Buzz Buddleja breeding programme and has been selected for a very low growth habit. First impressions suggest some Nanhoensis in the background with its very narrow leaves. There are also possibly several new colours of these ground-cover Buddlejas coming from Thompson & Morgan in the near future. Colour Fountain Blue also has bears a resemblance to several of the new Flutterby Petite plants from Peter Podaras in both foliage and habit although it is 100% B. davidi and not a B. davidi X B. alternifolia hybrid like the latter. Some Buddleja News from the Horticultural Trades Association National Show late in June. The industry trend really is towards the small, sterile Buddlejas as these start to out-sell the traditional plants. Eagle Plants is preparing four of the diminutive Flutterby Petite series for full garden centre release next year under the Free Petite name: Blue Heaven, Snow White, Dark Pink and Tutti Fruiti. Some of these are already available mail order as small plants but it is probably better to wait for the larger garden centre plants. Brandsford Webbs has abandoned full production of Lo and Behold Buddleia Red Chip (called Miss Molly in the USA) due to propagation problems but are full steam ahead with other Dennis Werner introductions: Lo and Behold Blue Chip, Lilac Chip, Purple Chip (Purple Haze) and White Chip (Ice Chip) all joining the excellent Miss Ruby. Purple Chip looks most interesting with its robust-looking foliage and pendant purple flowers. Lo and Behold Red Chip is still available from a few European nurseries and it is a rather inbred cultivar. It is a seedling from Miss Ruby x Attraction, Miss Ruby itself being a cross of Attraction and White Ball. The flowers are a pleasing shade but are essentially the same colour as Miss Ruby, maybe a shade darker, the selling point being that it is a smaller plant. What is remarkable is that Red Chip and Miss Ruby share a colour with Sugar Plum and Buzz Red despite differing pedigrees, although I believe they all ultimately derive fom Royal Red. The reason would seem to be down to chemistry - this shade is the closest to red that Buddleja davidii can produce with the pigment producing enzymes it currently has. Only a significant mutation or (gasp!) genetic engineering are likely to deliver a true red. Next month all the B. davidii cultivars and hybrids should be in full swing. | Buddleja Colour Fountain Blue is also called Foot Long and has flowers that are lilac rather than blue.Lo and Behold Red Chip is also called Miss Molly and has flowers that are a similar shade to its parent Miss Ruby. |
Lo and Behold Purple Chip joins Blue Chip, White Chip (not shown), Lilac Chip (not shown) and Miss Ruby in the UK. |
Spring was late starting but now everything is finally catching up. The first B. davidii flowers buds are forming already so they are mostly at the same stage as this time last year. A few weaker plants may still lag behind but not for long. Species that have normally flowered by the end of May are only just starting to come into bloom now at the end of June. Buddleja alternifolia is just starting to flower now although it has been in leaf for some time, as is Buddleja globosa: delayed but getting back on track. This is a great opportunity for hybridisations because species that normally flower over a month apart could be in flower at the same time. |
B. alternifolia has only just started flowering at the end of June. |
B. araucana has slightly deeper orange flowers and narrower leaves than B. globosa. | There are a few cultivars of Buddleja globosa but the origin of many plants is unknown. My plant has large dark green leaves and bright orange flowers but others have paler flowers and smaller leaves. Buddleja araucana (formerly called B. nappii) is a very similar species but can flower a little earlier in a normal year. It seems most of the specimens in the UK are derived from a shrub at Kew Gardens in London. B. globosa comes from the western Andes in Chile whilst B. araucana is more easterly, found in the eastern Chile and Argentinean Andes and the same area as the Monkey Puzzle Tree (Araucaria araucana). Although virtually indistinguishable the ranges of the two species do not overlap and there is not any evidence for intermediate types between the two species. The diagnostic feature, at least according to David Stuart who wrote the RHS Plant Guide on Buddleja, is the brown tomentum on the underside of the leaves, stems and flower buds of B. araucana. The leaves are also narrower and less bullate (that is a less crinkled top surface) than B. globosa. In the wild B. araucana is something of a xerophyte living in dry regions where the differences must be accentuated; it seems to be the soft life in England that makes it so much like B. globosa. The buds of B. globosa (left) are different to those of B. araucana (right). |
On the subject if identification: I have my doubts about the commonly available B. caryopteridifolia. The original description from the 1920s describes the plant as having very toothed leaves and this specimen was later sunk as a B. crispa by the botanist Leeuwenberg in 1979. The B. caryopteridifolia in the National Collections has smooth leaves and this is the same plant that I have. It is very hardy but deciduous and it is flowering now. It seems to flower fairly randomly in the early summer and/or autumn and sometimes twice in the same year. But the leaves are smooth and occasional branches have alternate leaves so it doesn't match the original description at all. Intriguingly, the flowers have the same scent as B. alternifolia and not at all like B. crispa. To me they smell of rose and chlorine whereas B. crispa has a refined honeyed spice perfume. There are hybrids between B. alternifolia and various B. crispa varieties. A plant found in the wild is B. x wardii is considered a hybrid of the two although this is sometimes treated as a separate species as there is no solid proof of its hybrid origin. There are several hybrids bred by horticulturalists, the best known is B. x pikei mentioned below. I suspect the plant currently identified as B. caryopteridifolia is a hybrid but which one? | The plant usually identified as B. caryopteridifolia (left) is flowering now. The smooth edged leaves are usually opposite but some brances have alternate leaves (right). |
Naming is always a problem for the plant collector. Species are difficult enough but cultivars can be really chaotic and the horticultural trade does little to help. Thompson & Morgan's Colour Fountain Blue is called Foot Long by the sister company Van Meuwen (I will maybe come back next month to look at this plant) and Buzz Red becomes Buzz Velvet. Names are frequently different in Europe and the USA. Lo and Behold Miss Molly has become Red Chip in Europe, not to be confused with Miss Ruby which is sold under its original name in the UK. Ice Chip has been changed to White Chip and Purple Haze is renamed Purple Chip. And it works the other way too: Argus Velvet and White are now called InSpired Violet and White in the USA with B. x weyeriana Pink Pagoda thrown in as InSpired Pink. There are yet more new Buddleja cultivars, again from the USA: the Merry Magic Series (Purple, Violet and Orchid) promises to be well behaved and, although B. davidii, non-invasive due to a low seed-set. Next month we can look forward to the beginning of all those B. davidii flowers!. |
The flower panicles are much smaller this year on Buddleja salviifolia. | Spring is so late this year. The few warm days in May have allowed plants to catch up only a little and I would estimate everything is four to six weeks behind now. Temperatures are remaining stubbornly below average and the growing season is getting shorter all the time. Even under cover the low light levels are having an effect. The flower panicles on Buddleja salviifolia are a fraction of their size last year although at least they are more or less on time. Buddleja crispa var. sterniana suffered in the late snow and the flower buds were desicated in the cold wind. Out of hundreds of buds just a few tiny flowers have emerged - better luck next year. But at least the plant is coming back into leaf now. These few flowers are all that survived the winter |
Talking of flowers, I have noted an interesting phenomenon with Buddleja 'Salmon Spheres' over several years. In warm conditions, whether inside or out, the flowers are quite pink fading only at the very end. Where it flowers in cool weather the flowers are more yellow-buff with a hint of pink, as are the flowers on mine now it is planted outside. It is proving very hardy too and growing very fast now, although as a hybrid of B. globosa B. crispa and you would expect some degree of resilience. This is in stark contrast to Buddleja ‘Winter Sun', a plant I have yet to make flower. It's very similar as a hydrid of B. araucana (a species almost indistinguishable from B. globosa)) and B. officinalis but seems less forgiving of cold conditions. |
The colour of Buddleja Salmon Spheres depends on the conditions. |
I think my B. lindleyana had a bad year last year and the late spring has done for it. Unusually it lost all its leaves last autumn and no buds have appeared yet. It has a bit of a reputation, along with the related B. japonica, for being short-lived in some circumstances. It also has a bad reputation for suckering, but on this occasion this is an advantage. Several new little plants are springing up about 50cm away so I will be able to start again but obviously in a different position. The difficult decision is what to replace it with - so many choices! | Buddleja lindleyana appears to have died but is still throwing up suckers. |
The seedlings I described last month have continued to develop. Its quite clear now that all the B. alternifolia seedlings are hybrids - I have a tray of twelve and they are all more like B. crispa than the seed parent. Likewise the B. loricata seedlings still have leaves unlike the seed parent and I can't even guess at the pollinating species yet. I will come back to these again as the summer progresses. Finally, a variegated Buddeja davidii cultivar I have recently acquired. Sir John comes from Stone Green Nurseries in Kent and has foliage similar to Santana but with the yellow/green a bit more randomly distributed. The flowers are pink-purple but I will have to wait until July-August to see these. |
These Buddleja loricata seedlings look unlike the parent plant - | Buddleja davidii Sir John has foliage like Santana |
Last time I said that last winter hadn't been too bad. And then came March, with snow and freezing temperatures for much of the month. The worst March since 1963 and then a cold start to April, although the second half is heading to be average. This means there is little going on now. Even the winter foliage remaining on the B. davidii cultivars was frazzled in the cold winds but most of those dead leaves are removed at pruning anyway. The pruning of B. davidii and its hybrids needed to be left until the freezing nights had passed, and actually mid-April is a perfect time to prune for an August show of flowers when those newly emerged butterflies are on the wing. Many plants still look dead but will soon start greening up again. Sadly all the B. crispa var. sterniana flower-buds were destroyed in the constant cold east wind. Unless the early spring flowering plants are in a particularly sheltered spot (or under some form of cover) there is always a risk that the flowers will be lost to the cold. But tiny green shoots are starting to appear from the bare stems so all is not lost. The flowers may be lost but Buddleja crispa var. sterniana is starting to recover. | Buddleja crispa var. sterniana has had its exposed flower-buds killed and dessicated by the cold wind. |
The B. alternifolia seedlings have opposite and crenate leaves very unlike the seed parent so are probably hybrids. |
One thing that was possible in March was to sow seeds. A warm windowsill is a good place or a heated propagator is even better for the seed trays. Some seeds benefit from a little cold treatment, others don't but I have not systematically tested which do benefit. I kept all sorts of seeds last year but those from the species Buddlejas are most interesting. The genus Buddleja is quite promiscuous with species from different continents happily hybridising. Buddleja Silver Anniversary (syn. Morning Mist) is a cross of Asian B. crispa and African B. loricata; there are many examples of Asian/American hybrids: B. x weyeriana and Salmon Spheres for example. So where there are many species jammed in together you never quite know what you will get in the next generation. There hasn't been much systematic research into self-compatibility and self-incompatibility in Buddleja but it is known that B. davidii doesn't self-pollinate. Some others may be able to such as B. crispa var. farreri and B. yunnanensis. Many species from the Americas have separate male and female plants (dioecy) so the question doesn't arise for them. I have been told that B. alternifolia might be self-compatible but it seems likely that out-crossing is more favoured. The seedlings that are developing now from its seeds look nothing like the parent, with opposite leaves that have crenate (wavy), not smooth, margins. It is possible that immature plants don't resemble the adult but it is far more likely that these are hybrids, probably B. caryopteridifolia providing the pollen. I have been told that B. alternifolia hybrids can grow into large ugly shrubs. There is no guarantee that this hybridisation will lead to a worthwhile plant but it has been tried already. B. alternifolia X B. caryopteridifolia is known as B. x pikei after a hybrid made by a Mr. A.V. Pike at Hever Castle in Kent, the best cultivar named Hever. |
The B. loricata seedlings also have toothed leaves very unlike the species so are these hybrids or just an immature form? | Buddleja loricata also produced copious fertile seed but I expected this to be the result of self-pollination. The seedlings are uniform but again look suspiciously unlike the seed parent with ovate, toothed leaves. Will they develop the smooth-edged strap-like leaves of B. loricata (see the picture below) or are these hybrids too? If they are hybrids will they be of any horticultural merit? Only time will tell. |
After winter the Buddleja Diary is back for the 2013 season! But not many flowers to see yet. This winter has been mostly mild but so very wet. Temperatures have often been below freezing but only just even in the snow, unlike a couple of years ago. Many exotic Buddleja need a mild winter to survive outside but he constant damp can be an equal problem. Waterlogged soil can be lethal for Buddlejas, even B.davidii. Disease can get in, especially the fungus Phytopthera sp. which will kill even a well established plant by damaging the main stem at ground level. Botrytis is another fungal problem, mostly under cover. Fortunately this attacks the leaves and only in exceptional cases killing the plant, late summer cuttings being the most vulnerable. It is always worthwhile removing affected leaves and cutting away parts that show the fuzzy grey mould. Some plants have proved to be much hardier than expected. And much happier planted outside rather than kept in a pot under cover. B. loricata hails from South Africa but usually grows at altitude so needs some resistance to cold. Mine has continued to grow slowly all winter and is totally unfazed by snow. Salmon Spheres, a hydrid of B. crispa and B.globosa, is considered a rather tender hybrid with similar needs to B. crispa. My greenhouse plant is reduced to few leaves and looks rather sad whereas one planted outside has thrived in the snow, keeping all its leaves and even its flower buds. Perhaps its hardiness is akin to the other parent, B.globosa, which is pretty tough but often looks a bit sad in the snow. | Buddleja loricata doesn't mind the snow, is evergreen and very hardy. |
Buddleja sterniana seems hardy
| B. sterniana, or more correctly B. crispa var. sterniana, had proved hardy over several years although is cut right back in the hardest winters. This year it look like most of the flower buds have survived the cold and has even retained some foliage. Like many spring bloomers it forms buds in the autumn which can be lost to the winter, but when these survive they open late March or in April depending on the conditions. It seems the endless stream of new, diminutive and virtually sterile Buddlejas continues. Peter Podaras from the USA, who gave us the 15 strong Flutterby Series, has four more plants out. One is a smallish plant, Purple Splendor. The others are really small, creeping types which will be marketed in Europe under the names of Dreaming Lavender (Lavender Veil in North America), Dreaming White (Angel White) and Dreaming Purple. So small they are considered suitable for hanging baskets. As with Flutterby these are complex hybrids and there are many more in the pipeline. The Argus series comes to us from Ghent, Belgium and these are hybrids of B.davidii and B.lindleyana. Small and sterile they are marketed as non-invasive. Argus Velvet is a purple and Argus White is, well, white. Last year Bransford-Webbs introduced Lo and Behold Lilac Chip to the UK but the release of Red Chip (originally called 'Miss Molly' in the USA) was delayed. This year Red Chip will be available alongside two more Lo and Behold plants, Purple Chip (syn. Purple Haze) and White Chip (syn. Ice Chip). |
What will happen to all these new small Buddlejas? There will probably be a selection process with just the best surviving. The market can't support so many plants and many will disappear from the catalogues, becoming extinct. Do we need a National Collection of miniature Buddlejas to preserve them? Probably not. Don't forget it will soon be time to prune those long-day (summer) flowering species, especially B. davidii, to keep them neat and floriferous. This February has been very cold so wait until late March or even early April. See: A Guide to Pruning Buddleja davidii. RETURN TO THE HOMEPAGE |