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.

Friday, May 19, 2006

Weed Control - Present and Future, Tomatoes and New Plants

Weed control is fundamental to good management

The control of weeds is fundamental to good garden management. Weeds not only look untidy, but also rob neighbouring plants of nutrients, play host to pests and diseases and shade out desirable subjects, thus resulting in their weak and sickly growth. Hand weeding is often necessary in the immediate vicinity of plants, although on some occasions a hoe can be used to good effect. In formal parts of the garden, like the vegetable plot, the hoe is the most efficient method of weed control, not only destroying the weeds before they have a chance to get a hold, but also creating a well-aired surface tilth.

Although weedkillers have a reputation for being toxic and unpleasant, this does not apply to all. Even the residual kinds are nowadays much more environmentally friendly than the sodium chlorate of previous years. On paths and other areas where it is not intended to grow plants, these provide protection for up to eighteen months. There are a number of systemic herbicides, mostly containing the active ingredient glyphosate. This is especially valuable as it is inactivated when it falls on the soil. It only reacts with green foliage and it is therefore important that weeds are growing vigorously before it is applied.

Systemic weedkillers are best for perennial weeds

Contact weedkillers based upon paraquat are very effective on annual weeds, but they must be treated with great respect, as they are toxic in the spray form to people. They have little lasting effect upon perennial weeds, merely burning off the foliage. Contact weedkillers depend upon destroying the plant tissue on which they fall and so complete spray cover of the foliage is necessary for a kill. Mulching can also contribute to weed control. Well-rotted manure, composted bark and garden compost are excellent weed suppressers. Black polythene and fabric mulches can also be used, but they do have limitations. They are especially useful in formal situations in the vegetable garden and the strawberry bed.

However, all these methods may one day become outmoded and we may have a completely chemical-free means of controlling weeds if scientists like microbiologist Joanne C. Chee-Sanford of the Invasive Weed Management Research Unit, Urbana, Illinois, United States have their way. "We’re interested in microbial activities in soil that lead to seed decay or reduced fitness for development. This approach differs from traditional biological control methods, where a specific microbiological agent is used against a pest species." Since 2002, she has been piecing together conditions under which certain microbes attack banks of common annual weeds. Some microbes are content to eat carbon and other nutrients present in the soil or exuded their from seeds, while others use powerful enzymes or other means to breach the seed, steal its nutrients, and cause decay.

Velvetleaf - Abutilon theophrasti

"We’re trying to identify specialist microbes that are adept at initiating seed decay, but seed decay may be a multimicrobe effort," said Chee-Sanford. In one study, 99% of Velvetleaf Abutilon theophrasti * seeds underwent microbial decay after 3 months, particularly when they were the only source of carbon available as food. Species of Bacteroidete and Proteobacteria, which are found in many soils and are known to degrade natural polymers, are the prime suspects in the seeds’ decay, although it is uncertain as to whether they are the initial cause of it. As these and other missing pieces of the ecological puzzle fall into place, investigations into microbial-mediated seed-bank reduction as a means of biological control can hopefully be developed and exploited. Normally biological control would call for releasing the microbes onto a targeted weed to fight it, but Chee-Sanford has a slightly different tactic in mind. Rather than apply microbes as biological control agents, she envisions bolstering the activity of microbes that already occur in the soils naturally, possibly using an amendment of some kind.

*To learn more about Velvetleaf click here.

Chelsea Show Gardens Preview
During each of the days running up to the Chelsea Flower Show I am previewing a show garden. Although these are often regarded as garden theatre and not as sustainable under normal gardening conditions, they are often full of interesting and innovative ideas which can be taken, at least in part, and used in our gardens at home.

Saveurs de France

This courtyard garden is intended to conveys the spirit of French life. The garden designer, Jane Dickins, originally sketched the garden on a table napkin, over a glass of wine at a restaurant in Arras in northern France. In her design, she says that it has been her intention to distil the essence of many typical French towns or villages. Part of the broad pavement is often enclosed with extravagantly planted Versailles tubs and trellis either for private use or for a restaurant or café.
The planting ranges from pinks to deep purple, with dashes of vibrant yellows and vermilion. The plantings include lavender, fuchsias and pelargoniums.

TomatoMessenger eNewsletter

Today the blog is "double value" as I have converted the monthly eNewsletter of the TomatoMessenger group into a blog and attached it as a separate entity at the end of today’s presentation. So when you get to the end of this blog, if you are interested in tomatoes, please continue scrolling down. I hope that you enjoy it.


Grape ‘Sweet Scarlet’
Sweet Scarlet is a mid-season ripening seedless grape that is said to have "crunchy flesh, thin raspberry-red skin, and a hint of muscat flavour."

Grape ‘Autumn King’
A large fruiting, mild tasting but sweet, white seedless cultivar. It apparently has very good keeping qualities too.

Syringa ‘Old Glory’
A lilac with abundant fragrant, bluish-purple flowers, a rounded growth habit and disease-tolerant foliage. In 25 years of testing at the US National Arboretum, it grew nearly 3.45m (11.5ft) high and a little over 3.9m (13 ft) across. It has shown good tolerance of both Cercospora blight and Pseudomonas syringae, especially in warmer climates where these diseases are a problem. It has also shown good tolerance to powdery mildew.

Syringa ‘Declaration’
This lovely cultivar produces fragrant, dark reddish-purple blossoms in sprays up to 30cm (12in) long on a shrub of upright habit. In 25 years of testing at the US National Arboretum, it grew 2.6m (8.5 ft )high and about 1.95m (6.5 ft) across wide. It is recommended primarily for traditional, cooler lilac-growing regions. Both of these cultivars were developed by the arboretum.

It is expected that planting stock of both cultivars will be available from a limited number of nurseries this year, and should be available from most retailers in 2008.


17th, 18th, 19th, and 20th August
The Lady Pilkington Centre,
Victoria Park,
Rotten Row,
PR8 2BZ,
Web-site click here.

Happy Gardening



Today’s Sponsor

Weeds: Wikipedia
Velvetleaf: Virginia Tech
Chelsea Garden: Royal Horticultural Society
Grapes: USDA
Lilacs: US National Arboretum

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

To join the GardenMessenger gardening community
click here

To visit the SeedMessenger seed exchange web-site
click here

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