Here in New Zealand, there were no mammalian fauna, until the introduction of rats, mice, deer, sheep, goats, opossums, etc. In the absence of large browsing animals NZ evolved a unique and interesting flora.
Now, however, we have most of the varieties of animal life found anywhere else in the world, excepting the large mammals like bear, elephant and lion. Only these large mammals are not so welcome in my garden - believe me, a herd of cows can trash your garden in an incredibly short time. Deer too, are a significant pest in our native forests, (along with public enemy #1: the opossum).
So my efforts at attracting wildlife are primarily aimed at birds, insects, and small mammals/reptiles. However, if you live with large mammals nearby (and not in New Zealand), then the presence of adequate food, in the form of smaller animals plus insects, is primarily what you need to attract them.
Most of us have few needs. Air, food, water, and somewhere to breed. The specifics of requirements change from species to species. A general statement that can be made is that an all year round supply of flowers and seeds for food, and rough areas for habitat, is needed. Winter and early spring especially, are feed times to look at, as that is when the supply drops off the most. Plants for flowers, seed, perhaps some water, and some undisturbed places to nest in is the basic recipe. Observation of the animal life in your area is a good place to start. Take note of food, and nest sites, and these can be expanded once they are identified.
Allow plants to go to seed as much as possible. In the vegetable garden, especially, it is beneficial to leave a block of plants, when harvesting, to go off to seed naturally. The next things can be planted around this block, which not only looks more natural, but helps to confuse the spotting instincts of pest insects.
Saving your own seed is also a way to be growing a plant which is healthier, and generally more suited to your conditions, if you are allowing a few of the best plants to go to seed. Broadcast sowing, allows seed to pick the most suitable microclimate to germinate in. Especially if you broadcast seed through a wide range of areas in your garden.
Low or no Tillage
One of the great gardening fallacies, is that it is necessary to dig deeply, weed thoroughly, and plant in straight lines. The 'no dig' and organic gardening ideas, are now widespread, and many books have been written on the subject. Compost, and mulch are the essential ingredients of an organic garden. As well as the many benefits to fertility, ease of cultivation, and soil structure, these methods also have the effect of dramatically increasing the invertebrate food resource for wildlife.
Make compost. This not only provides a free, perfectly balanced fertiliser and soil conditioner, there are many creatures, like hedgehogs and worms, which will feed themselves there. Worms are there for the vegetable matter, hedgehogs are there to eat the small insects.
Basically, you can't have too much compost, and it is a foundation of soil health.
Fertilise in spring, when plants are actively growing, not autumn when they are winding down for winter, and excess nitrates are leached away. (This leaching causes a process called 'Eutrophication' - an 'algal bloom' which troubles some coastal fisheries, where excess algal growth results in a large amount of decomposing vegetation. This has the effect of 'sucking up' too much oxygen from the water, which can dramatically impact the whole system. )
The Wild Garden
It is a good idea to allow a portion of the garden to go wild. It can be allowed to grow whatever it likes, within the limitations of maintenance (controlling noxious weeds, mainly).
Grasses are a good food and breeding habitat plant if allowed to go off to seed. With grasses, it is important to be aware of the needs of ground nesting birds, which usually are nesting in spring. This means that any mowing (which is not needed in the wild garden, but is necessary in a meadow/prairie planting) should be delayed until late spring when nesting is over.
Chuck in any left over seed from the vege garden, Brassicas and Umbellifrae especially. These are a good food source for many (including us if we run out). If the wildgarden is unmowed, you can expect the natural succession of species to take place -shrubs in 3-4 years, and trees in 7-10 years.
Food: Mammals eat vegetation, or some of the other lifeforms listed below. For this reason, their food requirements are pretty much what the others eat. Attract the others and the mammals will come too, to feed on them. (if you live next door to a large reserve).
Habitat: the main thing is size. This is possible, even in an urban environment. Getting a whole community to agree on what to do will give the habitat size needed. Otherwise, buying land next to a reserve, or other large natural area is necessary (at least to have the larger mammals visit). The bigger the animal, the bigger the supply of smaller animals to eat must be. This is primarily a function of habitat size. It takes a large habitat to support large mammals (elephant, kangaroo, human).
Food: Supplementary feeding is easy with a birdfeeder. A board on a post, with a lip around the edge (they are messy eaters), a nail to put the occasional apple on, and a hook to hang a string bag from. Birdcakes made of seeds, breadcrumbs, old cakes, rice or oatmeal (cooked first), mixed with animal fat to form a cake, hung in a string bag from the bird feeder will give hours of delight to the birds..
All plants will make seed if we allow them to. Even in the vege garden, it makes sense to leave a small patch every time we harvest, to make seed for the birds (and us). This can be replanted around easily, and creates a more natural look. Incidentally, this is also a good practice to confuse the homing instincts of pest insects. Also incidentally, insects are a great food source for birds, and a healthy garden has room for a few pests, which are balanced by that life which feeds on them.
Habitat: Birds need an undisturbed place to nest in, either trees/shrubs, or long grasses, sedges, and rushes, for ground nesting birds. It is important to be aware of the nesting behaviour of birds when maintaining meadow or prairie gardens. Mowing is the primary maintenance (once or twice a year), and most birds are nesting in spring, so wait until late spring when they are finished!
Butterflies/Bees/Nectar feeding birds
Food: Nectar is the thing that brings bees in to our gardens. In order to get their fix, they pollinate our plants for us. Imagine if we had to pollinate every plant in the garden! Nectar is provided by having a wide range of flowering plants, all year. Honeydew is an important source of food in winter, which is produced by aphids, scale insects, mealybugs
Shrubs and trees which produce nectar can also attract Tui or whatever nectar feeding birds are in the area. Phormium, Eucalyptus, Melaleuca, Metrosideros, Coral tree, Vibernum, are a few. A shallow dish of water, and rocks for butterflies to bask on will be used too, place these near the water, and place high, away from cats.
Habitat: Many bees are ground nesters, usually in dry banks or bits of bare ground, which tend to occur in between larger clump-forming grasses, and plants which are allowed to grow and seed. Nests can be made for solitary bees (eg. mason bees) by drilling 5/16" holes in blocks of wood, and hanging them in the trees. Fruit trees especially benefit from this, and the planting of a floriferous understory. Nectar feeding birds need nests. Butterfly larvae usually cocoon themselves on the food plant appropriate for the species.
Plants for bees: Myrtaceae, Leguminosae, Compositae, anything with shallow flowers, really, which includes most of the plants we grow for food and flowers. Marigold, Phlox, Aster, Borage, Verbena, Valerian, Daisies
Plants for birds: Grasses, Sunflowers, seed bearing trees/shrubs.
Plants for butterflies: Asclepias fruticosa (Swan plants) are well known for attracting the Monarch butterfly. Also any other Asclepias species (Milkweeds, etc), Araujia sericofera, Schinus molle (pepper tree), Tweedia versicolor (Oxypetalum), Buddleia, Cosmos, Lantana
Beneficial and pest insects
Food: The food supply for this group is eating your cabbages right now! Accepting a certain loss, and not immediately reacting to pests with the sprays is necessary if you want predators in your garden. Many pests breed quickly, while there is a time lag before the beneficials catch up. Be patient. Once a population of predators is in place, the response to pests is much faster.
Habitat: There are particular plants which attract different predators. The Umbellifrae family, and Phacelia are plants which attract hoverflies and parasitic wasps for example. As well as planting things which specifically attract the beneficials, it is important to provide a rough habitat - I usually call this a wild garden. Whether this be large or small, allowing nature to grow what she likes, with the minimum of human intervention necessary to keep persistent or noxious weeds out, and perhaps the planting of native tree and shrub species. It is important to allow weeds and grasses the opportunity to seed themselves. (again, with only the minimum control necessary). These seeds provide food for many, and long grasses/weeds provide habitat.
Some beneficial insects: Ladybird, Lacewing, Hoverfly, Ground beetles, Parasitic wasps, Rove beetle, Centipede, Bees, Worms, Ants, Spiders, Preying mantis.
Some 'pest' insects: Codlin moth, Ants (debatable), Aphids, Slugs, Snails . . .
Plants for beneficial insects: All Umbelliferae (parsnip, carrot, parsley, fennel), all herbs (Rosemary, Lavender, Sage, Thyme, Lemon Balm), Compositae (sunflower, goldenrod, daisy, Cosmos, Jerusalem artichoke, Rudbeckia, Coreopsis), Cleome, Phacelia, Borage, Comfrey, Nasturtium, Clover, honesty, Valerian.
Don't expect a wildlife pond to be a swimming pool. Shallow water between 10 and 100 cm deep is the range which most wildlife likes to use. A pond below a dam cleans itself of silt, so it is possible to dam a stream, have a shallow pond above for the wildlife, with rushes, sedges and water plants, and swim in the pond below the dam. Test the dirt. Clay is the basic ingredient for sealing a pond. Bentonite is a natural clay sealant which swells as much as 20 times when wet.
Oxygenate for fish and breakdown of organic material. The plant world gives us oxygen weed, also we can create structures such as a waterfall, fountain, surface aerator (splash), diffusion aerator (bubbles). Most of the water plant experts in the U.S. are now saying that water plants do better when the water is still or slow moving and that those creatures that feed from water environments do better when plants are the main aerators.
Its like no-till gardening. Excessive aeration of the soil by plowing gives the soil microorganisms excessive oxygen which results in a premature burn out of the organic material. Excessive aeration of the water by using aerators does pretty much the same thing. The fish may require an aerated environment but most of the aquatic micro-organisms like stiller waters, and it is the aquatic microorganisms that are central in aquatic life.
One of the features of a 'natural' water system is the way water passes from the 'catching area' or catchment, through a series of 'filters' (sedges, rushes, and bog or edge plants generally) before it passes into a stream, and then on to rivers, lakes, and finally the sea. This can be emulated by not having 'a pond', but a series of ponds. Especially if we want a swimming pond, and wildlife, this is the case. A series of shallow ponds, leading to a deeper 'swimming hole' is ideal, as it can provide a series of different habitat, for many species, including us.
Edge plants: Iris, Daylily, Hosta, Mint, Astilbe, Rodgersia, Ferns, wild Japanese Millet, (seedsource), Birds foot trefoil, creeping red Fescue, Junegrass, Canadian blue,
Water plants: Lotus, Waterlily, Oxygen weed, Wild rice, Bulrushes, Cattails
Pesticides destroy beneficial life forms, as well as pest ones. It has been estimated that 1% of insects in the garden are pests! To kill all of the insects that feed on pests (beneficials) in order to get the pests is a bit silly, to say the least.
Our use of pesticides affects the whole planet; traces of DDT has been found in Antarctic penguins. The greatest concerns are about organochlorines, and organophosphates. These chemicals have the property of accumulating in fatty tissues, which has the effect of increasing the concentration as the chemical moves up the foodchain. Fortunately, these chemicals are no longer used in the western world (much) - they are, however still used in third world countries, to the detriment of us all. Their endemic poverty creates a climate where things are done, not to the best, but to the cheapest. In a socio-economic climate where multinational chemical companies cannot sell this portion of their product in the first world, but are allowed to do so in the third world, the problem is serious.
The real point, is that chemical intervention is not necessary, except as a last resort. It is quite natural for any system to balance itself over time. If we take a longer view, this balancing act can be allowed to go on to its conclusion. In the process, many forms of life take part.
Take for example an 'infestation' of just about any pest you care to choose. If we take the opportunity to learn, rather than just reacting with chemicals, we will see our crop being eaten first. Then we will see a variety of predator insects come to feed on the
'pest'. Next we will see birds, hedgehogs, and other insect eaters come to the feast. After that, the higher animals may visit to feed in turn. These ones, (bear, vulture etc) require a much larger habitat, and are therefore only ever visitors.
At the end of all this, we will see that the crop losses (for seed crops anyway) were much less than we thought at first. Occasionally we may lose more, but in a balanced, diverse environment, there is always something else to eat, or pick flowers from.
Predator insects tend to hang around once in your garden, so any losses tend to be a 'one off', not repeated next year.
Farming and gardening organically are about a slow, steady increase in the health of the land. The healthier it is, the greater the web of life it can support. If we embrace this web of life (which we humans are part of), and actively encourage it, rather than singling out one aspect which is judged as 'bad', then we find that raw nature is not antagonistic to us humans, but embraces us in the rich tapestry of itself.
To put in simple terms, occasional pest damage is not only OK, but necessary to feed a population of predators.
If we are to create a garden friendly to wildlife, then that must include all wildlife to the best of our ability.