This blog reviews the latest products, plants and innovations in gardening. It also provides a link for my many gardening friends who are members of the GardenMessenger and Seedmessenger Yahoo groups and their sub-groups that I moderate.

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Location: Australia

I am a semi-retired UK botanical garden curator and former international horticultural consultant, who has worked extensively in Europe, the Middle East, North America and Australia. I spend part of the year in Australia and part in Europe, mainly due to family and work commitments. I earn my living from writing and editing Internet copy, articles and books. I have written over fifty books on gardening and have been translated into twenty-four different languages. I am a former UK Garden Writer of the Year and a previous Quill & Trowel Award Winner from the Garden Writer’s Association of America. I am interested in developing gardening communities on the Internet and I manage the popular GardenMessenger Yahoo group, along with its various sub-groups like PondMessenger and SeedMessenger. I also edit International Water Gardener and its associated regional web-sites.

Sunday, May 28, 2006

Controlling Late Blight, European Trials and Figs

Late Potato Blight - devastating

Agricultural Research Service plant pathologist, Modesto Olanya , and colleagues at the New England Plant, Soil, and Water Research Laboratory in Maine, United States, are investigating plant essential oils—including oregano, thyme and lavender—and other biologically based approaches for the control Late Potato Blight, one of the most devastating potato diseases in the world. Potato plants infected with the disease, scientifically known as Phytophthora infestans, suffer rapid foliage deterioration and loss, and the tubers decay. It was this disease that was blamed for the Irish potato famine of the 1840s. Is a formidable opponent, for it quickly acquires resistance to widely used systemic fungicides, requiring researchers to constantly search for new ways to protect both farm and home garden crops.

The researchers have found that among the essential oils, oregano, (or marjoram), is showing the greatest promise as a Late Blight suppressant. In laboratory tests, it was discovered that oregano and other essential oils greatly inhibited the growth of the Late Blight fungus. If future studies continue to show promise, natural remedies such as essential oils, could someday reduce a portion of the many fungicides that we currently use to control Late Potato Blight. The research team are also looking at pairing essential oils with other natural products, such as beneficial micro-organisms. The essential oils do have some limitations to overcome. Apparently oregano is fairly volatile, meaning some of its fungi-fighting essence could evaporate from plant surfaces after it has been applied. Conversely, the oils can burn plant leaves if applied too generously. This is most interesting work that we should follow closely.

Hydrangea paniculata on trial

It is great to learn of European co-operation with trialling plants. So often the horticultural industries of important plant producing countries work in isolation.The Royal Boskoop Horticultural Society (KVBC) in The Netherlands have taken the initiative to expand the scope of their research work by taking plant trials to an international level. The resulting new Euro-Trials are the outcome of co-operation with the Royal Horticultural Society (RHS) in the UK, the Institut National d’Horticole (INH) in France and Germany’s Bund deutscher Baumschulen (BdB). The first group of plants now being trialled in these four countries are the many different cultivars of Hydrangea paniculata. The results from the trials are expected sometime in 2007.

Trial visit: Gardeners in the UK have an opportunity to visit the Royal Horticultural Society Hydrangea paniculata trial on 21st September. Further details later from the RHS.

Success with figs

There has been a lot of discussion recently about figs, particularly their successful cultivation in temperate climates. In tropical districts, especially those where there is low humidity, once figs are established, they generally take care of themselves. In cooler climates figs are usually regarded as an indoor fruit. This is partly true as in order to obtain a regular crop it does demand the protection of a greenhouse. In warm conditions three flushes of fruit can be produced, although most gardeners grow figs under unheated glass where one good quality crop in late summer is usual. Fig trees themselves are very hardy and will tolerate extremely cold conditions, tolerating -10°C (14ºF) and still surviving. It is the fruits, and the requirements of warmth and protection for these, which ensures that most gardeners grow the fig indoors, or at the very least against a sunny wall.

Figs grow best with a restricted root run. While they can be grown in a large pot or planter they are best in the ground where during the summer they can be given copious amounts of water. In a greenhouse or a border against a wall they are best planted with constraint. The traditional fig house has concrete box-like compartments in the border filled with soil from which the roots cannot escape. Figs benefit from a free-draining soil and must have a sunny position if they are to prosper. Pruning is usually undertaken during the winter months in order to restrict bleeding. Figs produce a very sticky white exudation, which during summer can be difficult to stop flowing if a branch is cut. Figs fruit on one year and two year shoots and these should be retained as far as possible. Weak, diseased and misplaced growth being removed. Few pests and diseases bother figs, but aphids do attack and leave a sticky deposit upon which sooty mould becomes established. Keep an eye open for greenfly and the moment they are spotted spray them with an appropriate contact insecticide. This will prevent the occurrence of the honeydew deposit upon which sooty mould becomes established. There are a number of cultivars of figs available, but the universally popular 'Brown Turkey' seems to be the most reliable.


UK Marrowthon
Although officially announced in March, the UK Marrowthon is just getting under way. If you want to take part, then you do not have a moment to lose. Everyone, from children through to expert growers, are invited to participate in this great nationwide fund-raising charitable event. £1,000 worth of National Garden Vouchers, gardening equipment prizes and trophies will be awarded at the Marrowthon Grand Final in London on Saturday 16th September. There are Junior, Adult and Team marrow competitions, with classes for weight, length, decorative and ‘unusual looking’ marrows. Details click here.

Papaver nudicaule ‘Poppy Bussana’
A lovely new Iceland Poppy that was originally bred for cut flowers, but also makes a lovely border plant. Free-flowering and in a wide range of colours. It won the title ‘Most Promising Novelty’ as a cut flower cultivar at FloraHolland 2005.

Hippeastrum 'Mocca'
This is a cultivar that has been bred for cutting, rather than as growing as a houseplant, although it can be used for both purposes. The petals are an unusual orange-brown colour with the pale green undersides. It bears at least four, but usually five, and sometimes more flowers on each stem. These are up to 10cm (4in) in diameter.

Veronica ‘Christa’
An unusual cultivar that grows like any other hardy herbaceous Veronica, except that its spikes of dark blue blossoms end as a cockscomb. The tips of the flower spikes are green when young.


RHS Pinks Open Day
14th June
Garden Meeting Room,
Hillside Events Centre,
RHS Garden
Web-site click here.

Happy Gardening



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If you have enjoyed this publication, you may also like to visit the monthly SeedMessenger gardeners’ seed saving and seed exchange blog click here.
and the weekly water gardening blog PondMessenger click here.

Late Blight: USDA
Hydrangea paniculata: Royal Horticultural Society
Fig: Wikipedia
New Plants: Flower Council Holland

To join the GardenMessenger gardening community
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To visit the SeedMessenger seed exchange web-site
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