29 June 2001



Anyone thinking about

diversifying cannot have

failed to notice the large

number of advertisements

claiming that worm farming

is big business. But will it

really increase farm profits

and how much investment

is needed to set up?

Wendy Owen spoke to West

Yorks worm wholesaler

Charlie Denham

CHARLIE Denham has been involved in worm farming for 38 years. Trading as Wonder Worms UK and Tommy Topsoil, his Sowerby Bridge business supplies worms to anglers and worm compost to gardeners.

It also sells breeding worms and equipment to around 150 farmers who use spare buildings or odd corners of the yard to set up the worm beds. They have the option of marketing the worms themselves or selling them back to the company for £5-£10/kg, depending on market prices.

About 85% of the worms sold in the UK are imported so there is a huge scope for expansion, says Mr Denham.

"Anyone thinking of setting up a worm farm will need a minimum of 10,000 breeding worms to start off with. That will cost about £500 and provide enough worms to multiply and create a viable business within 18 months to two years."

Basic equipment requires a further £500-£1000 investment for every 110sq m bed added, depending on existing facilities.

"A meaningful farm enterprise would need between 2m and 5m worms and cover about 300sq m, producing up to 60kg of worms/week when fully populated. At £5-£10/kg, that adds up to a possible gross income of £300-£600/week," says Mr Denham.

It takes about 30 weeks for the worms to mature to the 2gm each which the market requires. Most farmers harvest the worms by hand into a woven sack containing 5kg of worms and a peat mixture, although Mr Denham uses a mechanical harvester. They are then sent off by courier.

Compost, which is harvested annually, provides another source of income and a standard 100sq m enterprise will generate a potential £2500 a year, says Mr Denham.

"Every 100sq m of worm bed will produce 50cu m of compost/year which can be sold for at least £50/cu m, or £100/t. We do not buy back compost unless the farms are very close to us because it is an expensive product to transport. We do supply bags and marketing materials and contacts, however, and farmers sell it themselves, either at the farm gate or to local garden centres. The normal retail price for a 40-litre sack is between £2.50 and £2.80."

Close to the surface

The best time to harvest the compost is in late summer, he advises. "Earlier in the year when the weather is colder, the worms have burrowed deep into the bottom of the beds. In warmer temperatures, the worms stay close to the surface and are easier to separate from the compost."

There are several choices when setting up a worm bed. Indoors, the worms can be kept in 400-litre plastic containers. Kept outside, good drainage is needed and worm beds are made from, 2m-wide, timber-panelled bays costing about £50 each for materials.

"We find that worms breed just as well outside as inside," said Mr Denham. "If they are kept outside, the beds can also be built of concrete blocks over a concrete footing. The housing must be fitted with anti-crawl bars because if they are under-fed, over-populated or there is heavy rainfall, they will crawl out of the worm bed and escape.

"The only snag to keeping worms indoors is that it can be difficult to get into the buildings to operate mini-diggers for mechanical feeding and digging out the compost. But the indoor compost does tend to be drier, which most customers prefer."

He has found that composted, straw-based cattle, pig or sheep manure is ideal for feeding the worms but any vegetable or paper waste can also be used. Poultry manure is too high in ammonia, while spent mushroom compost is too alkaline and often contains pesticides.

The straw-based manure needs to be stored for a minimum of two weeks under plastic sheeting to break it down before it can be fed to worms. Each 100sq m worm bed will eat its way through 3cu m of manure each week.

Over the years, Mr Denham has used feeding and management techniques to develop what he calls the Bluenose, a large manure worm variety developed from an earthworm.

"The larger worms survive transportation much better and fishermen prefer them," said Mr Denham. "They also breed at lower temperatures so there is no need to have a hot manure for them to multiply."

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