The Buddleja Garden

Neotropica Vol 81:

by Eliane Norman
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Buddlejas by
David D. Stuart
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Click images to enlarge

Buddleja limitanea

Posted 17th July 2017

B.limitanea is a smaller version of the vigorous B. forrestii, and many consider them to belong to the same species. There are, to my knowledge, at least four cultivars of B. limitanea currently in the UK. This one, grown fom seed recently collected in Yunnan (China), comes via Brighton Plants, and is a very pretty pink, rather than the more usual muted mauve-purple. It should be reasonably hardy, being from 3300 metres elevation.

B. davidii Nanho Blue

Posted 7th July 2017

Sometimes we can get obsessed by the new, and forget about some of the old cultivars. Nanho Blue (syn. Mongo) is one of the oldest varieties and is out of favour, losing its RHS AGM in 2010. I recently started a new plant from a cutting and it has reminded what an attractive plant it can be, with its long, blue flowers and its small, narrow and dark foliage. However, it is one that can get straggly and sparse if not correctly pruned and fed.

Buddleja loricata

Posted 22nd June 2017

B. loricata, also called Mountain Sagewood in its native South Africa, is an underrated Buddleja and more people should grow it. Fully hardy, evergreen and an excellent foliage plant, the flowers are a bonus. Usually appearing in June, the white flowers are in corymbs rather than panicles and are a little different from the more familiar members of the genus.

My own plant has grown rather unruly, but has flowered to an extent I have not seen before, completly covered in white inflorescences like clouds - and a fantastic citrus/spicey scent on warm days. Sadly, the flowers have just finished and it is due for a rather severe pruning. By pruning now rather then the autumn it should have time to put out new growth before the winter - I must remember to mulch and feed to ensure it has the nutrients needed to regrow vigorously - and be ready to produce another stunning display next June.

Buddleja nivea
Pink-flowered form

Posted 17th June 2017

There are a few forms of Buddleja nivea in cultivation, - this is the pink-flowered form from the Buddleja National Collection at the Longstock Nursery, Hampshire. Like the more common purple form, it has big velvety leaves and furry stems (indumentum) and, until it flowers, appears to be the same plant. The inflorescences are very open (interrupted) panicles and the individual flowers are an attractive light pink; each little flower is smaller than those on the pruple form and lack the large yellow-orange eye. However, the throat has the dense hairs typical of the species and the corolla tubes are similarly short, although narrower.

Much as with the other B. nivea plants - including Buddleja nivea var. yunnanensis and the plant labelled as B. stenostachya - it's really for the dramatic foliage that these plants are grown, as the flowers are fairly insignificant. I have grown hybrids of the purple form with much improved flowers whilst still retaining the hairy stems and foliage, but the purple colour is dominant - this pink form does offer the opportunity to produce hybrids with flowers of another colour.

My thanks to Peter Moore for the plant.

The more common purple B. nivea.
The pink form of B. nivea

Buddleja nivea var. yunnanensis

Posted 7th June 2017

Buddleja nivea is a very variable species and several types are in cultivation, including this one from Yunnan in China. The Yunnanensis variety is much larger in size than the species type, easily reaching four metres or more in height; a doubling of its chromosome number possibly accounts for its size and vigour. It's quite common in culitvation and is mostly grown for its dramatic large, furry and serated leaves. Although hardy, the foliage is vulnerable to very cold or strong winds, so its not suited to an exposed site.

Given it's a large Buddleja with exciting foliage, the flowers are something of a disappointment. The individual flowers themselves are pretty much the same as the species type - purple, short corolla tube with a hairy throat - and the panicles are long, but the flowers don't open in strict sequence along the inflorescence; a few open and here and there and never provide a rich display of colour. This doesn't seem to matter to pollinators and the flowers are still a bee magnet.

Buddleja globosa X Buddleja araucana Hybrid

Posted 31st May 2017

I asked myself the question why so few people had tried to breed a better B. globosa. The answer, it seems, is that the seedlings are fiddly to grow and you have to wait several years to get flowers. And then everything comes out orange. A couple of years ago I crossed B. globosa with B. araucana, formerly B.nappii, a closely related species with brighter flowers. Finally, a couple of the seedlings have flowered… orange. The hybrids are almost perfect intermediates between the parent species. The longer, narrower leaves and fuzzy stems are inherited from B. araucana; in the photo the leaves can be compared to the B. globosa foliage in the bottom right-hand corner.

The two seedling that have flowered (so far) are different sexes - in the female (see below) flower the stamens are completely absent, whereas the male has evident white stamens shedding pollen (below right). Every male seedling I have raised from my female B. globosa has these obvious pale stamens, although the common male B. globosa cultivar has more orangey-brown stamens. I'm also growing the progeny of Lemon Ball, a distinct B. globosa female cultivar with lighter orange flowers, and I am hoping the resulting males won't have such bright stamens, although I will have to wait until next year for these to flower.

The B. globosa X B. araucana hybrids have longer, narrower leaves compared to the B. globosa foliage (in the bottom right-hand corner). The pale yellow flowers in the background are HCM98017.

The female hybrid, note the lack of stamens.
The male hybrid, note the white stamens shedding pollen.

Buddleja glomerata

Posted 19th may 2017

B. glomerata is a plant I would not grow outside because it needs dryish condition. This presents a problem, as the plant can soon become potbound; then it flowers less and looks unhappy. The answer is to not just prune the top growth, but to trim the roots too. Last summer I knocked it out its 15 litre pot, took off any conjested roots and, returning it to the same pot, replaced about half the contents with fresh compost mixed with a little slow release fertiliser.

And this is the result the next spring - a happy plant covered in fuzzy flowers. It is trick I have used with a few a Buddlejas now. The alternative is to have all the tender Buddlejas in 100 litre pots, which is rather impractical in a tiny greenhouse.

Buddleja x wardii KR4881

Posted 9th may 2017

On the My Species page I took the bold step of applying my own identification and name to this plant, believing it to be a white-flowered form of B. alternifolia previously known as B. tsetangensis. I have waited a year to closely examine the flowers; although a healthy plant with very attractive foliage, it's extrememly parsimonious with its flowers when grown outside.

B.X wardii is considered a natural hybrid (or intermediate) of B. alternifolia and B. crispa; the original specimens were collected in Tsang-po valley (Tibet), a region where both species grow, and close to where the only known specimen of B. tsetangensis was collected.

Dissecting the flowers has convinced me KR4881 is not a hybrid of B. crispa, and hence is not B.X wardii. In the photo the ovaries of two Buddleja crispa types (plants of this species still frequently labelled as B. sterniana and B. agathosma) have been freed of the corolla and calyx, and are shown together with a dissected flower from KR4881. The difference in shape is striking, with the KR4881 ovary, style and stigma (gynœcium or female parts) being completely unlike either of the B. crispa examples. According to the literature, the female parts of B.X wardii should resemble those of B. crispa, with thick tomentum covering the upper half of the ovary and continuing onto the style. In KR4881 not only is the ovary shape and size very different, but the tomentum is sparse and restricted to the ovary; all its features are much more akin to those found in the flowers of B. alternifolia, and not intermediate between the two species. I also examined the flowers of "Longstock Gem", an artificial hybrid of B. alternifolia and B. crispa, and the gynœcium of this plant is almost identical to that of B. crispa.

I am pretty certain the plant should be labelled B. aff. alternifolia KR4881; B. tsetangensis has been reduced to a synonym of B. alternifolia and should no longer be used.

To return to the B crispa types, it is quite remarkable how different the two plants mentioned appear to be, with the leaves and corolla of B. agathosma four or more times the size of those of B. sterniana, yet the gynœcium scale and morphology are virtually identical, providing good evidence they should be included in the same species.

Buddleja sterniana

Posted 14th April 2017

Things are starting up in The Buddleja Garden at last. This past winter has been very mild indeed and has meant stalled flowers buds have survived. Many of the spring-flowering species and hybrids are beginning to open now, such as the Crispa Complex species B. agathosma and B. sterniana. Winter Sun, a hybrid of B. araucana has also flowered very well.

My B. sterniana was planted out a few years ago and didn't appear to do much at first. Orginally, I kept the plant in a pot where it stayed small and produced only a few weedy flowers. I was unsure whether it would prove hardy in a south-facing, but exposed, position. This year, however, it has finally exceeded my expectations; outside it has grown into a large straggly monster about 3 metres tall and 4 metres wide. The flowers, which appear before the leaves, cover the entire plant and from a distance it looks like a pale pink cloud. The plant is in for a shock - as soon as the flowers finish it is in for a rigorous pruning to tame its straggly character. It should regenerate into a denser, better shaped shrub by the autumn.

The 2017 Buddleja Diary is here!

Posted 8th April 2017

It's time to prune Buddleja davidii - I always prune summer-flowering species and hybrids in April. There is already a page on pruning, so I won't go into details. Remember - don't prune spring-flowering species until after they have flowered.

Watch out for those reverted, all green shoots on variegated cultivars such as Harlequin - like the one on the centre of the photo. Remove any branches now with reversions and keep a check once the growth restarts - the reverted shoots will be much more vigorous and could eventually take over the plant.

Buddleja forrestii - I have had some success with one B.forrestii planted in the garden, which has proved to be quite hardy. I have a second cultivar, one with massive leaves, already 30cm long, and brown tomentum. It's still in a pot and I've never seen the flowers - but it is growing well and I am making space for it so it can grow to what must be an impressive full-size. I have been warned this one might be a little less hardy, but I will take the risk as they never seem happy confined.

Buddleja Diary for 2017 coming soon!

In the meantime, here are a few antique prints to enjoy; click to enlarge.

Buddleja colvilei

B. alternifolia

Buddleja alternifolia
Buddleja x intermedia

B. intermedia

B. japonica

Buddleja japonica
Buddleja sessiliflora (as Buddleja verticillata)

B. sessiliflora

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