Survival Gardening Diary
October
The big tidy up
October is a great month for tidying up in preparation for autumn/winter sowings of garlic, beans, peas or green manures. The residue of crops that are finished can be put into composting boxes, allowing the ground to be weeded and prepared for the crops to follow. It is not a good idea to leave the land bare over the winter months as winter rain will leach out important soil nutrients. If there is no food crop to be planted until the spring then the ground should be sown in a green manure - a crop of something fast growing that will cover the ground quickly and which can be dug into the soil or cleared away when the ground is needed for planting.
Almost anything can be used for green manures, but not all seeds will germinate in the cooling autumn conditions. The most suitable are fodder peas, clover, mustard and rye. Mustard will be killed off by the winter frosts, so is best sown along with clover or peas. Surplus vegetable seed - ends of packets too small in quantity to be worth saving for the following year - can also be used as a green manure, especially peas and beans, and many salad vegetables. Sometimes it is OK to leave the weeds as a green manure - this tactic may be preferred by the guerrilla gardener who is endeavouring to maintain a low profile.
If weeds are to be left in over the winter, any flowering heads or seed heads should be removed as precaution against them becoming too well established the next year. Most weeds are native plants but some are opportunistic imports from abroad, typically garden escapees looking for new territory to occupy. There is a fine balance between tolerating weeds and letting things get out of control. Some weeds are all too efficient at spreading and should not be encouraged in any circumstances. These include silverweed (a native), ground elder (a very persistent non-native introduced to northwest Europe by the Romans), and bindweed (another native). All three can grow new plants from tiny bits of roots left behind in the soil and can be very hard to eradicate once well established.
Invasive shrubs
Among the invasive shrubs introduced to Ireland as garden plants, Japanese knotweed (Fallopia japonica) deserves special mention as it has so far resisted most attempts at eradication. It is extremely persistent and should be regarded as a potential threat to long term food security. Any piece of stem or root has the potential to grow into new plants. It is often inadvertently spread by developers and local authorities, either in the unrestricted movement of top soil around the country or by careless management techniques such as strimming. The latter simply scatters thousands of fragments in all directions.
The roots of Japanese knotweed have been known to spread up to seven meters from the parent plant, and it can push its way through weaknesses in concrete and brickwork. Mechanical eradication by digging up the roots has generally not been successful. It will only work if carried out with the diligence of an archaeological dig, with all soil sieved in order to remove every last fragment. The plant material thus gathered should be heat treated/ pasteurised on site in a controlled manner if at all possible, so that there is no risk of fragments being spread during transportation. The residue could then be composted.
Ideally there should be a decontamination zone for mechanical diggers and other machinery so that soil can be removed from the tyre treads prior to them leaving the site. Treated sites should be carefully monitored for at least three years, with follow up sieving operations each year. Half hearted attempts at eradication only make the situation worse.
In the UK, £1.6 billion has been spent on Japanese knotweed eradication, with only very limited success. While this is probably more indicative of poor eradication management, and overcharging by contractors, it also illustrates the scale of the problem. The UK is now planning to introduce a predator - a beetle - from Japan, with unknowable consequences. Also, the predator will by no means eradicate the knotweed, but simply reduce it in volume.
The survival gardener should maintain vigilance for Japanese knotweed, and also for another invasive plant Gunnera (Gunnera tinctoria), which is described by the Galway Biodiversity Project as "spreading out of control in the West of Ireland". While this might be a slight exaggeration, Gunnera covers large areas of eastern Achill (in Mayo) and is common in many other coastal areas. It is sometimes called giant rhubarb, owing to its rhubarb-like appearance and enormous dimensions - up to three meters tall.
Local authorities should be made aware of the appearance of either of these plants. Contact the heritage or environmental officers. If the local authority does not show signs of taking the situation seriously, it is worth making a fuss in the local media and instigating public awareness campaigns.
More to follow...
Happy gardening
Andy
