A sound organic approach is to minimise opportunities for pests to prosper, rather than having to deal with unexpected damage. Put simply, gardeners have the ability to reduce pest problems through good gardening.
SLUGS AND SNAILS
Slugs are a fact of life, even for those who regularly use poisons to control their numbers. A better approach is to understand more about them, both to stop their numbers escalating and to adapt to their ways.
• Correct timing of sowings is one strategy for coexistence, so that seedlings thrive in helpful conditions and are able to grow away from any nibbles. Look closely at the recommended dates for different vegetables in Part 2 (Chapters 9 to 19). Also, if possible:
• Sow seeds in controlled environments such as a greenhouse, where they can grow unmolested into strong plants that are large and vigorous enough to resist the slimy marauders. This is a vital aspect of growing any early crop, whose health and vigour says to Mr Slug “Hold off here! I am growing well so leave me alone, or just nibble my fading outer leaves. Your job is to clear up the debris!” In other words, slugs have a place in the garden, but hopefully not too many places.
• Reduce slug habitats as much as possible. Areas of unnecessary weeds, rubbish, long grass or overgrown plants can all be shelters to surprising numbers of the larger multicoloured sorts, which can destroy even large seedlings in a short spell of damp weather. For instance, once my rhubarb is growing I have an occasional look under the lowest leaves to find snails that are lurking in the dark coolness, waiting to come out for a nightly feed on anything nearby. Keeping the soil clear of weeds in springtime is vital; so is removing the leftover leaves and stems of any finished crops to the compost heap or bin, as soon as possible after harvest.
The greatest slug damage often occurs where ground has recently been cleared of grass or overgrowth that was home to large numbers who, suddenly, have less to eat than before. In the first year of cropping such ground, I would avoid growing slug-prone vegetables such as salads, spinach and carrots. The least problems arise in a tidy garden where only the crops are growing, but nearby habitats can still make difficulties. Walls and stony borders are an invitation to snails to set up home, so it is best to grow resistant flowers together with fruiting trees and bushes near to walls, and site the vegetable patch a little way from them.
SLUG- AND SNAIL-RESISTANT FLOWERS
Slug- and snail-resistant flowers that I grow include penstemons, wallflowers, auriculas, campanulae, cornflowers, sweet williams, foxgloves, Verbena bonariensis and a wide range of other perennials. Note that certain plants whose leaves offer little culinary interest to our slimy friends can often serve as shelter to large numbers, so it is beneficial to conduct a clean-up in damp weather. A little foraging under leaves should soon reveal favourite hiding places. Slug-tender flowers such as French marigolds and dahlias need to be grown in more open ground and planted a little later than often recommended.
Night-time forays Another trick, for the brave gardener of nocturnal instinct, is to venture out with a torch and maybe gloves as well, and pick off everything that has appeared under cover of darkness – there can be a surprisingly large number of slugs. Putting them in a bucket of water will drown them, or push a pointed knife through them.
Frequent harvests Even in bare soil there are always slugs – chiefly the small grey ones who are notably conscientious in their tidying-up role. When lettuce matures and develops a heart, I find that the decaying outer leaves become home to large numbers, whereas the heart that is still growing strongly and has the youngest, healthiest leaves is mostly free of damage. My sales of lettuce used to be always limited by the presence of at least one slug, even after trimming off the damaged outer leaves. People just do not like dealing with them; supermarket buyers above all! So it has been a great joy for me to discover how to grow frequently picked lettuce – whose small and less-numerous leaves afford little shelter – as well as finding that it is feasible to mix leaves in water so that slugs are washed out. Chapter 9, Summer Salads, explains how you can achieve this and produce your own salad bag.
Predators You may be wondering if it is possible to encourage sufficient predators into a garden. Personally I feel that this helps, but not to the point that we can ever cease to be alert to the dangers, because slugs and snails are themselves simply part of the garden. Our role is to keep their numbers at a manageable level. Sometimes when picking spinach I disturb a toad sheltering under the leaves – they like the same conditions as the slugs they eat. But there are always slugs on the spinach as well, which makes sense because if the toad ate them all he or she would have to go elsewhere. Ducks or hens will clean up a garden, but I never let them into the vegetable patch because of the damage caused by hens digging and ducks nibbling. When we lived in rural France it was clear that poultry were encouraged to range all around our neighbours’ farms and gardens, but never in the carefully fenced potagers.
Slug traps Slugs like a cool, dark, damp place to shelter in daytime. Laying something such as an old wooden board on the soil will often result, the following morning, in being able to remove many slugs from underneath it. Slugs also like a drink at night and can be lured into saucers of old beer set into the soil, but these need regular inspection and refilling.
Slug pellets If your patience is exhausted and you reach for the pellets, there are now ‘organic’ ones available. I would be careful to limit their use, to avoid a build-up of iron phosphate in the soil, and personally I have found them ineffective in really wet conditions, when you could use a VERY FEW of the chemical ones – one per plant and preferably under a cover, from where the poisoned slug(s) can be removed and binned. Most applications of metaldehyde poison are far too abundant and casual, whereas their extremely limited and careful use in occasional severely wet weather is, I feel, better than losing whole crops to slugs.
INSECTS
The importance of sowing dates
After slugs, the most common difficulties are caused by cabbage-family caterpillars, to the point that I rarely grow late-summer cabbages and calabrese. At that time of year, cabbage white butterflies are abundant and laying many eggs, especially in sheltered gardens. Measures can be taken to keep them out of crops or even to kill them, but I prefer to grow cabbages and other brassicas in the winter half of the year, when their predatory insects are much rarer. Suitable dates for all brassicas are covered in Chapter 14, together with tips on reducing pest damage.
Put another way, for all the vegetables you grow, think which is the best time of year to sow and grow them for the least difficulty with insects. For example, peas sown in late winter have a fair chance of cropping before pea moths lay their eggs; cabbages for spring that are sown in late August will mature when there are no caterpillars at all; and carrots sown in mid-June avoid the spring flights of carrot root fly, and should be clean until October.
If, on the other hand, you sow seed on dates that do not respect the potential insect problems for any crop, you will need to spend time and money on remedies. Sometimes it may feel worthwhile; other times not, and in later chapters I suggest the sowing dates that offer most chance to each different vegetable of avoiding serious insect attack.
Attracting beneficial insects
There are many ways of maintaining a better balance of insects so that you have enough predators nearby. Remember that pests are usually present, but in small, scarcely noticeable numbers because other insects are eating them – aphids and hoverfly larvae, for example. More predators can be encouraged by having the widest possible range of plants, including many flowers and a few stinging nettles.
For indoor growing, suitable predators (which do not usually survive the winter) can be purchased in spring, but beware of being persuaded into spending a lot of money on a problem that may not happen – see pages 168 (aphids) and 172 (red spider mite).
WOODLICE
Woodlice can peck away relentlessly at tender young leaves, making serrated margins. If this happens – and you rarely see them as they eat by night - you need to raise as strong and healthy plants as possible for setting out, rather than sowing seeds direct in the soil where woodlice can damage so many emerging leaves.
BIRDS
Pigeons above all, but also partridges and pheasants, can systematically strip leaves off peas, brassicas and salads, particularly in winter and spring. If this happens, you will need anti-bird netting. For example, drape a roll of 4m (13')-wide mesh over semicircular wire hoops spanning the beds.
Sparrows love to peck at seedlings of beetroot and chard, sometimes salad too; even blackbirds may learn this trick. In springtime, fleece offers excellent protection against birds, as well as helping to protect plants from cold winds.
Badgers
During dry spells and cold winters in Somerset, badgers often come into the garden searching for worms and slugs, perhaps because recently spread compost on top of the soil is an easier source of this food in dry and frosty conditions than their more regular haunts. Some of my first plantings are occasionally dug up as badgers look for little worms in the modules’ compost. Yet in spring they usually return to the fields, having in fact reduced the slug population at a wonderful time – just before the major plantings of early spring.
However, I am still extremely nervous of badgers because they are power ful and can be extremely destructive when, for instance, they are foraging through a row of peas to satisfy their sweet tooth, or rapidly destroying rows of sweetcorn to devour its slightly immature cobs. As a protected species, they may not be hunted.
Rabbits
Rabbits are another concern. They can enter my garden because I hate putting up fencing, which would also need to be dug in so they can’t burrow underneath. A partial solution is provided by our two cats, who live outdoors and occasionally bring home young rabbits to eat. Numbers vary, and most springs I suffer some damage, with onion, leek and garlic seedlings almost disappearing, before they grow away strongly in a warm May.
Rabbit numbers and eating grounds fluctuate all the time, but severe infestations might be tackled by paying somebody to bring in their ferret. Or some fencing may be necessary, but this can be an onerous undertaking which involves maintenance as well.
RABBIT FENCING
I admit to ambivalence over fencing rabbits out because it is such a major job: digging a narrow trench about a foot deep and lining it with mesh fencing, which should emerge above ground to about 80cm (2'8"). Or instead of digging it in, the mesh fence can also be laid flat on the ground, outside the fence, to a distance of about 60cm (2'): grass will grow through it and can be kept mown. Or you can run two strands of permanently electrified wire around your plot, about 15cm (6") and 30cm (12") above ground level. However this is clearly bad for children, can be broken by badgers, and any grass below the fence needs regular cutting to prevent the electricity disappearing down blades of grass into the soil.
I suggest a similar approach to diseases as to pests, aiming to understand where problems are likely and then gardening to avoid them. For instance, potatoes are notorious for succumbing to blight, such that whole crops can be lost. This can be avoided by growing one of the new blight-resistant Sarpo varieties; or if you don’t like their slightly floury texture you could grow a more waxy second early variety such as Wilja, which matures in August, often before the worst blight arrives, and its early harvest can be kept for use through the winter.
If crops are lost to pests or diseases, you need neither despair nor reach for an expensive cure. Learn from what has happened and do it differently next time, to avoid the worst pitfalls. There is often slight damage, but we should be able to afford some losses if our soil is well composted and growing abundant, healthy crops.
The essence of gardening is learning how everything fits together and how to respond as different situations arise. It is a continual learning process, never devoid of interest and always changing. Every season throws up new challenges and opportunities. The next chapter looks at ways of increasing the chances of success.