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The type of formal garden associated with Cambridge is clearly a long way removed from the natural state of wild land in Britain; by creating such an environment we are preventing many of nature’s regulatory mechanisms from working normally. In a sense, then, we are taking it upon ourselves to control an essentially unbalanced system - these areas would rapidly revert to scrubland if there was no human intervention. The challenge, from an environmental perspective, is therefore firstly to minimise that imbalance, and secondly to reduce the impact of the measures we take to keep it under control.
state of play
- Most colleges compost most waste if possible.
- Many colleges are willing (and have tried) to use peat alternatives such as coir, but find them too expensive.
- Three extremely unpleasant garden chemicals are still fairly commonly used, although their use is banned in many other countries (see pesticides )
- Soft soap insecticides and natural fertilisers (such as blood, fish, bone meal and chicken manure) are commonly used. Robinson use biological pest controls (whitefly predator, red spider mite predator and nematodes); Magdalene use pest resistant varieties, as well as companion planting and ground cover plants to control weeds.
- Robinson, New Hall and Fitzwilliam have areas set aside for wildlife.
With the possibility of metering in the near future, gardens which use minimum water are a sound investment. Shrubs and bushes are better moisture traps than exposed lawns or beds; certain species are more resistant to drought than others. Details of methods of low water-use gardening are available from Anglian Water (see page B11).
The perfect lawn is virtually a symbol of the age and formality of Cambridge institutions, yet it is a rather fragile system, seeking to banish diversity in favour of an even, velvet sward. The maintenance of this sort of lawn involves an incredible amount of work, as well as the external input of nutrients. There seems to be some sort of shift in public taste away from the extremely formal garden, in favour of less regimented pockets of ‘nature’ in an urban setting. Granting, however, that most colleges would be unwilling to abandon their lawns entirely, it might be possible to use more resilient, less ‘hungry’ grasses. More importantly, perhaps, it would certainly be possible to reduce the amounts of artificial fertilisers and pesticides used on lawns . feeding
The use of artificial fertilisers on lawns causes untold damage in the life of the soil, eventually leading to impoverished land which requires more and more feeding as time goes by. A goodly proportion of fertiliser ends up, again, in the Cam, stimulating the growth of algae to the detriment of the river’s ecological balance. There are perfectly acceptable organic alternatives to artificial lawn food, including:
Downing College is having a trial year using chicken manure for their lawns rather than synthetic fertilisers.
- Blood, fish and bonemeal for nitrogen and phosphates
- Seaweed meal for potash
- Organic manures for all-round feeding - ‘Cowpact’; ‘Super Natural’.
The basis of all organic gardening is compost- all organic matter (grass clippings, weeds, leaves) can be returned to the land, supplemented, where appropriate, by Organic fertilisers. ‘Activators’ may be obtained which speed up the creation of usable compost (from Fertosan and QR). The survey shows that most colleges currently try to compost as much garden waste as possible. An innovative scheme run by the student green group in Newnham involves the swift and hygienic composting of food wastes by tiger worms. These worms are widely used in the waste disposal industry, producing a very high quality compost. There would seem to be great potential for their wider use in colleges, where a liberal supply of organic wastes from butteries represents a vastly undervalued resource. HDRA sell small-scale Brandling worm bins for around £45. If composting on site is impossible, allotment societies may accept garden waste.
Another way of composting is to use garden waste as a mulch. In this way, nutrients are returned to the growing plants, soil moisture is conserved, and weeds are suppressed. Several colleges have bought shredders which convert woody biomass into suitable material or mulching. It might be possible for neighbouring colleges to share these facilities, and their cost (around £250 for a 1600 watt ALKO shredder). Lawn mowings, cocoa shells (a byproduct of chocolate manufacture), newspapers, old carpets, or plastic bags are alternative mulching materials.
A way in which college gardens could be developed is to integrate wildlife areas which would add both diversity and a more native feel to college gardens. Robinson College has a wildlife area of meadow and woodland; Fitzwilliam College is currently creating a wildflower meadow. A wide range of wild flower seeds is available from the HDRA catalogue.
Peat, though organic, is a non-renewable resource, and its extraction causes profound damage to the environments where it is found. There are a range of alternatives to peat compost:
- Cocopeat (derived from coir fibre)
- Moorland Gold (recycled peat dredged from reservoir bottoms)
- Hortifibre (derived from sap wood of pine trees)
- Nature’s Own Seed & Potting Compost (from farmyard manure, bark and Moorland Gold)
- Cowpost (based on compressed cow manure)
Chemical solutions generally harm the creatures which keep pests under control as well as the pests themselves. There is also evidence that immunity to chemicals often develops (see pesticides) .The table shows common problems, along with samples of possible organic and biological controls. Magdalene College uses organic practices such as using soft soaps, companion planting, resistant varieties and ground-cover plants. Further details are available from the Soil Association.
Problem Example of solution with lesser environmental impact Ants 1. Boiling water
Aphids/Blackfly/Caterpillars 1. Soft soap
3. Biological controls i.e. Bactospeine for caterpillars, Encarsia for whitefly
Fungus problems 1. Cultural methods
2. Bordeaux Mixture
Weeds 1. Tolerance: some common ‘weeds’ could also be seen as beautiful wildflowers.
2. Hand weeding. More labour, but more accurate targeting.
3. Mulching ( in beds and vegetable patches, cover ground with straw, forest bark, newspaper, ‘Hortopaper’ )
Path weeds 1. Hand weeding.
Moss 1. Draining & aeration
2. Feeding of lawn (with poultry manure, dried blood, fishmeal, bonemeal for example)
Moles 1. Ultrasonic ‘electronic’ deterrents. Insects 1. Drainage / rolling ( of lawns )
2. Avoidance of monocultures
3. Encouragement of natural controls : toads, birds, hedgehogs, ladybirds.
Slugs 1. Natural controls.
2. Beer traps and dead wood traps
3. ‘Fertosan’ powder (not organic but most environmentally friendly product at present)
approximate price guide
peat alternatives :
- cocopeat (coir fibre): 40 litres @ £8.35
- coir fibre brick: 2 (or more) bricks @ £1.35 ( brick makes 8 litres of compost)
- moorland gold: 45 litres @ £6.75
- perlite: 25 litres @ £6.80
- hortifibre: 175 litres @ £16.75
- 'Nature's own':seed compost: 40 litres @ £5.25
potting compost: 40 litres @ £8.90
module compost: 40 litres @ £8.90
tomato compost: 40 litres @ 9.05
grow bags: 30 litres @ £5.85
- garden compost: 40 litres @ £7.60
- cowpact (compressed cow manure): 3x40 litre bags @ £22.95
- cocoa shell mulch: 80 litres @ £12.99
- fertosan slug powder : 2.5 kg @ £11.70
- garden fungicide: 500 ml @ £3.90
Chase Organics (GB) Ltd
Addlestone Weybridge KT15 1HY
National Centre for Organic Gardening
Coventry CV8 3LG
(The above companies have a combined catalogue, the Organic Gardening Catalogue , at the Chase Organics address)
Fertosan Products Ltd
2 Holborn Square
Lower Transmere, Birkenhead
Mersey side L41 9HQ
Cumulus Organics & Conservation Ltd
Two Mile Lane
Highnam, Glos GL2 8DW
86-88 Colston St
Bristol BS1 5BB
National Council for the Conservation of Plants & Gardens
c/o RHS Wisley Gardens
Woking Surrey GU23 6QB
Unit 42 Glan-yr-Afon Ind. Est.
Dyfed SY23 3JQ
British Earthworm Technology
Harding Way St.Ives
Cambridge PE17 4WR
Cambridge City Council,
Planning Dept. Landscape Team,
The Guildhall, Cambridge
(01223) 358977 ext. 2675
The Wildlife Trust (Beds & Cambs);
Cambridge Green Belt Project(address c/o Wildlife Trust)
The Manor, Fulbourn,
Cambridge CB1 5BN
PO Box 43
Tunbridge Wells Kent TN2 5BY
tel: (01892) 36 807
Holland's biggest biological control company. Some products are also available from organic gardening catalogue, including controls for greenfly, whitefly, red spider rite and vine weevil.
PO Box 595 Addstock
(0129) 671 3838
A range of products produced from cow slurry from farms with the Soil Association symbol, including cowpost and cowpeet as a peat alternative.
Fordham House, Fordham,
tel. (01638) 721100
Wonder Worms UK,
Pine Trees Farm,Hubbarton,
West Yorkshire HX6 1NT
tel. (01422) 831112
Unit 2b Longfield Road
Kent TN2 3EY
A range of organic gardening products, including rose feed, mosskiller and lawn tonic. Send an s.a.e. for details of local stocklist, or order direct.
Chesterton Allotment Society,
[sites: Histon Road, Kings Hedges Road, Arbury Road]
may accept garden waste for composting
A range of books and booklets is available from HDRA and Centre for Alternative Technology e.g.:
Forsythe, Succesful Organic Pest Control, 1990. £4.99
The City Council recommends:
Fran Hill, 1988, Wildlife Gardening - A Practical Handbook.