Bean Anthracnose, Colletotrichum lindemuthianum

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This is a post I would have preferred not to write, for it describes a plant disease I haven’t seen before and, quite frankly, don’t want to see again.

At the end of July we had four days of rather cool, rainy weather and soon after this, on 29th July, I noticed that our neighbour’s runner beans looked sickly. They had reddish-brown marks on the leaves (especially on the veins) and on the stems. The plants hadn’t started to produce bean pods. I searched on the internet and what I found suggested that the plants were infected with Bean Anthracnose. I ruled out Bean Rust (caused by the fungus Uromyces appendiculatus) – this appears as reddish-brown, raised pustules on the bottom of leaves. The article ‘Anthracnose and rust of garden beans‘ on the University of Minnesota Extension website shows the difference.

Bean Anthracnose

Bean Anthracnose on Runner Beans, late July

My neighbour agreed with my diagnosis and immediately destroyed her plants and put them in our council green waste collection, for composting at high temperatures. (Putting diseased beans on a normal garden compost heap won’t destroy the fungus, as the temperature won’t be high enough.)

Another month went by and one of my varieties of Climbing French Bean (‘Blue Lake‘) started to show characteristic spots on its pods, which I removed and destroyed. The disease has now spread to the Climbing French Bean ‘Neckarkoningin’ and the Heritage variety ‘Bird’s Egg’ is slightly affected. Heritage varieties ‘Caroline’s Purple’, ‘Poltetschka’ and ‘Bonne Bouche’ appear to be unaffected. As before, I have removed the affected plants, including shed leaves.

Bean Anthracnose

Bean Anthracnose on Climbing French Beans, October

This is the first time I have seen Bean Anthracnose. The book ‘Pests, Diseases and Disorders of Garden Plants’ (Stefan Buczacki and Keith Harris, Harper Collins, 1998) says that the disease is widespread on dwarf and less severely on runner beans, but usually only apparent in cool, wet summers. However, epidemics of the disease can occur in bean growing areas of the world with frequent rainfall, such as central and western New York State. In Brazil, India, China, Mexico, Myanmar, Canada, Argentina and the United States, anthracnose is considered to be one of the most invasive and destructive bean diseases and can destroy up to 95% of yield.

Bean Anthracnose is transmitted in the seed, a discovery made in 1921 by M. F. Barrus of Cornell University. Recommendations to prevent the spread of the disease include removing dead bean plants and their debris at the end of the growing season, digging over the soil so any residues are buried and following crop rotation so that beans aren’t grown in the same place for at least two years. This is all common sense, but the main inconvenience for me is that I won’t be able to save this year’s dried beans for planting next year.

There are quite a few resistant varieties of bean. The Garden Organic website lists ‘Forum’ (from Thompson & Morgan) and ‘Copper Teepee’ (from Mr Fothergill and Johnsons) and the Crocus website recommends ‘Aramis’.

Hopefully, this year has been a one-off. It is certainly the first time I’ve seen Bean Anthracnose in sixteen years of growing French and Runner Beans on my allotment.

Pineapple Weed, Matricaria discoidea

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Pineapple Weed

Plants make an impression in different ways. I love Erigeron karvinskianus (Mexican Fleabane) for its prolific flowers, Gunnera manicata for its giant leaves and Calabrese for its taste.

It is the smell of Pineapple Weed, Matricaria discoidea, that I like. It is usually my first impression of the plant, as I accidentally step on it as I walk along footpaths, pavements or over waste ground. It is a scent that takes me back to childhood and warm summer days in the countryside.

I first knew Pineapple Weed by its older scientific name of Matricaria matricarioides. It also has other English names, including ‘wild chamomile‘, ‘disc mayweed‘, ‘pineapple mayweed‘  and ‘apple virgin‘. It is a member of the daisy family, the Asteraceae, and has a rich smell of pineapple when crushed.

Its close relatives Chamomile and the Mayweeds* (which have a similar smell) have more typical ‘daisy’ flowers, with white ray florets around the outside of the flower head and tube florets in the centre. Pineapple Weed just has the tube florets, which are like small yellow buttons. It is either the plant’s smell or the shape of its flowers that give it the name Pineapple Weed.

Pineapple weed is an annual herb which flowers from June to September in the UK. It is not native to Europe, however, and was introduced to Britain in 1781 from North America. It escaped from Kew Gardens in 1871 and soon spread. In Finland it was first grown in Kaisaniemi Botanic Garden in Helsinki in 1849 but within a year it had escaped and is now found throughout the country.

Pineapple Weed  is a native of North-east Asia and the North-west United States. It is usually found growing in poor, compacted soils and roadsides. My nearest patch is on the verge of George Borrow Road in Norwich; I took the photograph above when walking from Bamburgh to Seahouses in Northumberland in June this year.

Pineapple Weed is edible, though some people are allergic to it. The chemical that gives the plant its characteristic fruity smell is a terpene called myrcene, which is also found in Basil, Hops, Mangoes and Cannabis. The plant also contains a coumarin called herniarin, and this may be responsible for the allergic reaction. The chemical has a range of biological activities, including haemostatic and anthelmintic properties (i.e. it can stop bleeding and can be used to expel parasitic worms). Extracts of Pineapple Weed also have antimicrobial properties.

The fresh or dried flower heads of Pineapple Weed can be used to make a herb tea (rather like chamomile) and the fresh flowers can be eaten raw in salads or cooked.

Pineapple Weed’s ribbed seeds can be spread on footwear. However, in “The Roadside Wildlife Book” (1974) and “Flora Britannica” (1996), Richard Mabey suggests that the motor car, and pneumatic tyres in particular, aided the spread of the plant in Britain, as the seeds stick to tyres. He quotes an experiment: in 1968 a car had its tyres carefully washed and was then driven along 65 miles of road following heavy rain, including passing places and field gateways. The tyres were then hosed down and the sediment was incubated in sterilised compost. Plants from 13 different species grew, including 220 seedlings of Pineapple Weed.

* A good name for a 1960s band?

Hunworth Hall Garden

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Yesterday I cycled to Hunworth in North Norfolk to visit Hunworth Hall Garden. It was quite hard work cycling into a cool north westerly wind but well worth the effort.

Hunworth Hall Garden

Hunworth Hall dates from the eighteenth century and was bought by the Crawley family in 1965. They created a tennis court, orchard and kitchen garden, but the area between these and the hall was a large paddock, grazed by goats. The present owners, Henry and Charlotte Crawley, moved into Hunworth Hall in 1983 and began to establish the extensive garden that can be seen today.

Hunworth Hall Garden

The garden is in the Anglo-Dutch style (as seen in the gardens at Westbury Court in Gloucestershire and Het Loo in the Netherlands), with formal hedges, canals and a folly. There are lollipop-shaped golden hollies, box balls, yews and a big beech hedge. A raised walk at the back of the garden gives views over the rest of the garden and a lovely big Eucalyptus tree overhangs a croquet lawn.

I love the formal elements but also the swathes of wildflowers (now past their best, but they must be teeming with insect life in July and early August) and the vegetables, the gnarled orchard trees, beds full of lavender and clusters of Echinops and other perennials, all of which soften the structure and bring life and humanity into this lovely garden.

Hunworth Hall Garden

The tea and Cornish sticky cake were lovely too. Hunworth Hall Garden was open under the National Gardens Scheme. (I missed the previous opening, in 2012.)

The weather improved just in time. I arrived in Hunworth just before 1 o’clock and ate my lunch at the church while I waited for the garden to open at 2 o’clock. The morning’s cloud melted away to leave blue skies and warm sunshine and I sat on a bench by the church door and watched Swallows and House Martins flying past, with a Buzzard and then a Sparrowhawk circling on the thermals over the small valley to the west. The churchyard, incidentally, is a superb example of how to manage grassland for wild flowers and wildlife, but also allowing public access. The wind dropped during the afternoon, but still gave me a helping push as I cycled home.

Hunworth Church

Hunworth Church