In our Christmas crackers last year we all found a packet of sunflower seed saved by my mother from plants she had grown, with the promise of prizes for various categories of sunfloweriness next season. These are some of the progeny from my packet, a nice mixture of warm colours. Note the pollen (and pollinators) - these will set seed, unlike the pollen-free F1 hybrids that are now so common, and which must lead to much frustration among those trying to grow sunflowers for bird food.
Friday 27 August 2010
Wednesday 25 August 2010
Agapanthus 'Northern Star'
Agapanthus is one of my favourite genera and makes a really valuable contribution to the garden at this time of year. Over the years I have built up a selection of different species and cultivars with considerable diversity of flower colour, shape and inflorescence character; this gallery gives a sample of some of them. Many have come from Pine Cottage Plants in north Devon, where Dick Fulcher has a wonderful collection and nursery specialising in Agapanthus. The fabulous blue 'Northern Star' (above) is one of his selections and is hardy in the British climate.
Agapanthus 'Sarah', an evergreen cultivar derived from A. praecox and thus better suited to pot cultivation in the UK. It has extra perianth segments, giving it a distinctive appearance.
Agapanthus 'Midnight Cascade' - probably not very hardy, but I haven't tried it outside yet.
Agapanthus caulescens is another deciduous species that has been used in breeding and selection and seems to be moderately hardy. It can give some interesting flower colours with a purplish hint: this is particularly obvious in 'Liam's Lilac' (left), a Dick Fulcher selection that has been hardy here for several years.
One of the great myths of gardening, endlessly trotted out, is that Agapanthus need to be crowded in a pot (or even in the ground, which seems strange) before they will flower well. Just try it. Crowding almost always means starvation, and aggies are greedy feeders - flowering performance almost always diminishes rapidly once the plants begin to feel starved. They do flower best when properly established, however, but establishment does not need to mean crowded.
Agapanthus 'Loch Hope', currently flowering extremely prolifically at Colesbourne Park (with Phlox 'Natural Feelings'); it is one of the cultivars selected at the Savill Garden in the 1970s and still a superb hardy garden plant. I bought a plant of it from there in 1983, from which this patch is derived. 'Windsor Grey' (below) is another from this stable.
Agapanthus 'Windsor Grey'
Agapanthus 'Selma Bock'
Monday 23 August 2010
Gladiolus watsonioides with Helichrysum nandense on Mt Kenya, October 2007
One of the plants whose flowering I most look forward to each year is Gladiolus watsonioides. This is an old friend from East Africa whose acquaintance I first made on Kilimanjaro in 1990, but have since met on other mountains. It is found only on the higher mountains of Kenya and Tanzania, growing in the forest and high altitude heathland at altitudes of up to 3900 m, making it the highest-growing wild Gladiolus. When growing above the forest it experiences frost almost every night of the year, as well as the unchanging pattern of equal day and night length through the year (Mt Kenya almost straddles the Equator): it is a pattern well characterized by the great Swedish botanist, the late Olov Hedberg, who described the climate as 'winter every night, summer every day.' In these conditions it grows almost year-round and flowers are always to be found, it seems.
In cultivation it is also of uncertain pattern, so in consequence I grow it in the cool greenhouse where its shoots may emerge at any time. Flowering, however, always seems to take place in late summer.
The plant I became familiar with on Kilimanjaro is a slender plant, with small, pale orange-red flowers, generally growing in openings in the upper forest: pretty but not spectacular (left, above). The species was first named from Kilimanjaro specimens in 1886, so when a larger and far more spectacular Gladiolus was found on Mt Kenya it was not unreasonable to give it a separate name, G. mackinderi, in honour of Sir Halford Mackinder who made the first ascent of the mountain in 1899. In my experience this represents a much more robust plant, typically growing in the high altitude heathland (as in the top picture, and above right), with larger, brighter red flowers, very different in appearance to the rather weedy Kilimanjaro plants. For the first time I have plants from both mountains flowering together in the greenhouse and I'm fascinated to see that the differences I know in the wild are also evident in cultivation (as these were obtained from British nurseries I cannot be accused of collector bias!). In the wild it seems that there is a continuum in flower size between these extremes, justifying the view that they are all forms of one species. For gardeners, however, there is no doubt that it is the Mt Kenya form that is the one worth growing.
Sunday 22 August 2010
My friend Tomoko Miyashita has sent me pictures and some comments about the useof the cucurbit Momordica charantia (Bitter Gourd) in Japan, where it is often used, as she does (above), as a fast-growing sun-screen to shade homes from strong westerly sunshine. This year she has planted two cultivars, the traditional green-fruited form, and a new white version, along with the equally fast-growing plant Cardiospermum grandiflorum.
She writes of the Momordica: 'This is not delicious vegetable at all but I am quite happy with this natural curtain.' Although its bitterness is not to my, or her, taste, it is a surprisingly popular vegetable in Asian cuisine and is usually available from Asian shops in this country.
Seeds of Cardiospermum grandiflorum, Heartseed: the heart-shaped white mark on the seed gives both its English and scientific names, but it is clearly intended for turning into a Micky Mouse face, as Tomoko has done here. The fruits of Momordica charantia are in the immature stage at which they are eaten. When ripe they turn orange and split to reveal red seeds, at which stage they are very decorative, but it needs a hot summer to perform well.
Saturday 21 August 2010
On the principle of a Snowdrop lunch, where enthusiasts gather to discuss their plants, yesterday afternoon I held an Impatiens Tea Party, for a few enthusiasts of this undervalued genus.Well, most of it is undervalued: Impatiens walleriana, the ordinary Busy Lizzie, is the world's most popular bedding plant, and as such is highly valuable to the horticultural trade, and apparently valued by those who plant it.
The focus yesterday was, however, on unimproved, wild species of this genus of about 1000 known species. They show extraordinary diversity of flower shape and coloration, as well as plant habit. Most are perennial, some are hardy and most not, with a few annuals. Most are from the tropics and subtropics of Africa and especially Asia, with just six species native to the Americas, and one in Europe.The genus fascinated Sir Joseph Hooker, who studied it intensively in his years of 'retirement', and his study of the African species earned Christopher Grey-Wilson his PhD. His monograph Impatiens of Africa (1980) remains the standard work, but there is no single treatment of the Asian multitudes. Their diversity, and the difficulty of making a decent herbarium specimen that retains some hint of the complexity of flower structure, gives taxonomists a sever challenge, and I am sure that there are many more new species to be discovered. In recent years the genus has had major champions in Britain and the United States: Ray Morgan from Swansea, whose book Impatiens, the vibrant world of busy lizzies, balsams and touch-me-nots came out in 2007, and Derick Pitman of Sacramento, 'Mr Impatiens', who runs a website devoted to the genus, with galleries showing a huge number of different species.
Prolific seeding is one of the demerits of some species in the genus, notably I. glandulifera, but when happy most species will produce self-sown seedlings. Among these is the Ethiopian I. rothii (pic at top), which provides a few seedlings for distribution each year. It has proven hardy here over the past five winters, dying down to large tubers like those of I. tinctoria, to which it is related, and emerging in spring to form a wide bush topped wth salmon-pink flowers.
The 'Impatient Gardeners' gather cuttings of one of the nicest hardy Chinese species, the white form of I. arguta (Roy Lancaster, John & Lynsey Pink, Derry Watkins, Ray Morgan).
Thursday 19 August 2010
This week we have been busy lifting dormant snowdrop bulbs from the garden and nursery. The bulbs are in perfect condition, plump and full - an ideal state for moving them around. When replanted they will soon push out new roots and quickly establish, growing next year as if they had never been moved.
The clump shown above, of the Greatorex hybrid double 'Hippolyta', is typical. It has been in the ground for several years and the bulbs have multiplied well, so there are several layers of them in the clump. If one tried to divide it in growth, as popular custom sugests, you would rip off most of the roots while trying to disentangle the bulbs, leaving each plant in a disadvantaged state for the growing season and resulting in a smaller bulb than if it had been left undisturbed. Last year's roots are still cleartly visible here, showing how long they persist: while not really active, these are very much alive and fleshy.
A clump like this is extracted from the ground in its entirety: at this time of the year the bulbs just fall away from the clump. Then they are graded, with some flowering-size bulbs being retained for sales while others, plus some offsets are replanted in the original (but widened and deepened hole) at a reasonable spacing. These will quickly develop to form a fine flowering clump again within a year or two. A few other smaller bulbs are taken off for replanting elsewhere. This system makes the offtake of bulbs from Colesbourne very sustainable: the spring display is not affected, and indeed enhanced, while providing a stock of bulbs to appear as potted plants on our sales table next February.
'Hippolyta' in flower - only five months or so to go... (for those who are feeling snowdrop-deprived)
Monday 16 August 2010
Each spring I am the grateful recipient of a box of seed samples from the Dutch vegetable seed company Rijk Zwaan. This is a major breeder and producer of vegetable seeds, with a strong international presence, but as with so many companies its name seldom appears on the produce we buy.
As a major commercial entity, the Salanova lettuce has a website of its own, and is the subject of a major promotional campaign - under the unfortunate slogan 'Taste the nova way of living'.
The easy preparation is indeed convenient - and the lettuces are nicely tasty - but I like them for their ornamentality. We grow them in containers outside the cottage door (top picture, red and green multi-leaf butterhead), enjoying their appearance before thinning them out for a salad, and in the vegetable garden they are also very decorative (above, red and green incised-leaf grown in a shallow crate). I think the green multi-leaf butterhead (below) is my favourite, not only for its culinary qualities, but for the tight, beautifully arranged head of leaves in growth, giving a suggestion of the 'quartered' shape of an old-fashioned rose, which increases as the head matures. Cultivation is as easy as for any other lettuce and I find that if a late sowing is grown in crates in the polytunnel they can be picked late into November.
Saturday 14 August 2010
Friday 13 August 2010
Thursday 12 August 2010
The Woody Plant Committee discusses Indigofera howellii.
Last Friday, 'fresh' off the plane, I went to a meeting of the RHS Woody Plant Committee at Wisley. After the business was over, we went out to inspect the trials of woody plants that are currently in progress.
Trialling plants for their garden-worthiness is a major function of the Royal Horticultural Society's work, conducted over all classes of plant. As wide an assemblage of material as possible is procured for each trial, and this is then grown together, with every entry receiving identical treatment. The trial is judged at intervals by the appropriate group from the Trials Committee - sometimes visiting every week or fortnight during the flowering season - and each entry is assessed for its qualities by a panel of experienced horticulturists. The aim is to see which plants perform best and can be granted the Award of Garden Merit for their all round performance: an AGM is an accolade to the plant and a commendation to gardeners. It has nothing to do with novelty, just steady garden performance, so can be won by any cultivar that achieves the standard required.
Clematis 'Purpurea Plena Elegans' dates from Elizabethan times: its extant AGM is likely to be renewed.
After lunch we went to the other end of the garden to see the trials of Weigela, Indigofera and related legumes, and Buddleja. I skipped the weigelas and only skimmed through the buddlejas as I needed to get home before the effects of an overnight flight took hold.
Wednesday 11 August 2010
In 1998, or thereabouts, I was sent a packet of seed of Agapanthus walshii, by Barbara Knox-Shaw, of Elgin near Cape Town. It germinated well and seedlings were potted up. Quite a few were given away and I kept some for myself. Most of them died, and since I came to Colesbourne in 2003 I have had a solitary plant, growing slowly in the greenhouse, and never flowering until now. It is potted in a mix of loam and a lot of grit, fed every week in summer with Phostrogen (it's a one-size fits all regime in the Colesbourne greenhouse).
The common Agapanthus in the area around Cape Town is A. africanus - the first of the genus to be discovered and grown in Europe. It is a winter-growing, evergreen plant, and has a reputation for being very tricky to grow: the name, however, is ubiquitous in the horticultural trade, but this material is always one form or another of A. praecox. This is a summer-growing evergreen species that, while somewhat tender, is at least amenable to ordinary pot cultivation and provides many of the best Agapanthus cultivars as selections or hybrids.
Agapanthus africanus has open-faced flowers held outwards in the umbel, like most members of the genus. It was not surprising then, that when an Agapanthus with pendulous, rather tubular flowers, was discovered at the Cape in 1918, it should be regarded as a new species. It was named A. walshii. Recent studies have shown, however, that africanus and walshii are very closely related, with the result that in their study of the DNA weight of Agapanthus (2003), Graham Duncan and Ben Zonneveld treat this plant as A. africanus subsp. walshii. It is a rare plant in the wild as well as in cultivation, and the largest known site (which Barbara and Graham took me to see in 2004) is being encroached on by what is known in South Africa as 'informal housing' - a shanty-town anywhere else.
I have been surprised at how tall the inflorescence is - I had been expecting something more in proportion with the fan of leaves - but illustrations of wild plants show that it always greatly exceeds the foliage. Although the leaves show no wax, the scape is strongly waxy. The pendulous flowers are very reminiscent of A. inapertus in their tubular shape and posture; they are said to vary in shade of blue in the wild, and white forms are known.