I live in Brisbane, on Australia’s East Coast. Brisbane has a sub-tropical climate, which means that in summer the average temperature hovers around 32 degrees and we virtually never get frost.
Summer here means very high humidity, hot enough to kill most European vegetables and flowers! We adjust to this by growing plants that can handle the heat, like snake-beans and chokos (a kind of tropical squash), basil, sage and rosemary and small Thai tomatoes.
All other seasons of the year are more cool and dry, which is actually great because it means we can grow pretty much any plant without trouble and without having to worry about frost. Plants only grow a little bit more slowly in winter, but other than that we have great all-year-round growing weather. In winter it is possible to grow all of the common European vegetables like broad beans, leeks, kale and courgettes and so on.
My garden is a completely pesticide-free garden. I never spray anything on it apart from some organic mineral supplements and liquid fertilizer, both of which are completely non-toxic. I water the garden using lots of water harvested from our 5000 liter rain-water tank that fills up completely in summer with the heavy monsoon rainfall we get here. I do use a special product called “Neem Oil”, which is a potent non-toxic oil crushed out of the Indian Neem Tree’s seeds. It is used to kill off curl grubs (the devastating larvae of the African Scarab Beetle). One curl grub can destroy an entire vegetable patch in a tropical climate like ours, where winter never kills them off! Neem Oil stops them feeding and forces them to surface, where they are then eaten by birds. Neem Oil has been used in Indian medicine for thousands of years and is not toxic to humans – it washes off the vegetable foliage and into the soil in any case.
Most people don’t realize that it is possible to grow a lot of nice vegetables without spraying pesticide to keep caterpillars and other pests away. In order to garden this way, you have to employ an ancient technique called Companion Planting, which means that particular (often inedible) plants are planted next to your vegetables to help ward off pests. About two-thirds of the plants in my garden are not vegetables at all, but flowers or herbs. Flowers are used as a repellent (meaning that they repel pests like caterpillars and nematodes with their odour) and as a food source for predatory insects. Predatory insects are a major helper in the garden, killing off pests like caterpillars and aphids very effectively. As soon as you spray any pesticide you will also kill the beneficial predatory insects like wasps and lacewings too, and you will probably kill bees that come along and are required to pollinate many kinds of vegetables. So my solution is to grow a LOT of flowers.
My favourite is Alyssum (Baby’s Breath), which grows thousands of tiny flowers all year round, has a nice scent, looks great, and provides lots of food for predatory insects like hover-flies and wasps. It is a little tricky to grow from seed (it requires light to germinate, so you can’t just plant it like other seeds) but you can buy 6-packs of Alyssum at your local gardening shop too if you don’t want to go to that trouble. I grow almost all of my plants from seed, because 90% of what I plant is an “annual” meaning that the plants only last less than a year on average. If I had to buy pre-grown seedlings it would cost me hundreds of dollars. The only exception to this is herbs, which are perennials and last a long time, so they are worth buying as seedlings because they are often very difficult to grow from seed.
Flowers also help to “hide” your vegetables from moths and butterflies – their eyesight is not very good, so if your cabbage is surrounded by a pack of Marigolds, they will fly right past and not lay their eggs! Herbs like rosemary and basil offer the additional benefit over flowers of very pungent odours that deter roving caterpillars and grass-hoppers from hanging around for too long. Basil in particular grows like a weed in Brisbane – I gave my neighbour three plants last year and he now has a big patch of basil that he does nothing with – he doesn’t even water it! When basil goes to seed the flowers attract huge numbers of beneficial insects. Occasionally you might even see very unusual blue native bumble-bees the size of a 5c coin coming to visit the basil flowers. And of course you can use it in your cooking!
Last but not least I also grow “trap plants” or “sacrificial plants” whose sole purpose is to offer a tasty meal that keeps pests off my more valuable vegetables. The prime plant we use for this purpose in Australia is Nasturtium, which is actually a very beautiful flower whose seeds, petals and leaves can be eaten as part of a salad – they have a peppery flavour. Caterpillars absolutely love these plants, which is great, because they will spend all their time on the Nasturtium and ignore things like cabbages and lettuce. Nasturtium seeds are incredibly cheap and easy to grow – just stick them in the ground and wait three weeks. I can get a pack of 30 seeds for $1.50, and you even get great-looking flowers into the bargain. Another great cheap trap plant is Mustard – I grow two varieties, one of which has enormous purple leaves 60cm high which make great caterpillar feed. The seeds are very easy to grow yourself and the plants are very hardy and look beautiful on the edge of a garden bed. You can grow 200 mustard plants from a packet of seeds that costs $3.50 – pretty good value! Mustard is also delicious in salads and can be eaten raw.
The last thing you need to get right is your soil and plant arrangement. I use spent mushroom compost, which costs $2 for a 60-kilogram bag I can barely lift at the local organic mushroom farm. That is amazingly cheap and the compost is made of a mix of rotting wood and manure, which is perfect for plants. As a bonus I often get edible Campignon mushrooms sprouting out of it! But I never eat these because you should be careful about picking random mushrooms, you can easily mistake a poisonous one for an edible one. I usually just crush them with my foot and then they rot back into the soil and return nutrients to it. On top of the compost I put a thin layer of cheap sugar-cane mulch. It’s amazing how much of a difference it can make to your soil’s moisture, and as a bonus it even smells nice! It also helps to stop vegetables that lie on the ground (like pumpkins and strawberries) from rotting by keeping them dry and off the soil itself. I mix some horse manure that I buy from local farms in the area into the compost. It usually costs about $6 to buy enough horse poo to fill a garden bed, and it is one of the finest things you can put in your garden – a completely organic and natural fertilizer that breaks down over a long period of time, giving your plants food for months on end and drastically improving your soil quality.
My garden’s arrangement is simple – flowers and tall herbs on the edges, and vegetables go in the middle. That way flying insects will encounter the tall flowers and herbs first, often knocking them back completely, and the vegetables in the middle get enough sunlight. This arrangement also looks amazing, because you see a bed of flowers that appears to have some nice cabbages and tomatoes growing inside it! In our front planter boxes on the street my 3-year-old son Frankie helped me plant several hundred cheap flower bulbs (total cost was about $70). They are a great option to get some flowers quickly on the cheap without the hassle of growing from seed – they have a very high germination rate and you can get some amazing varieties now. We are growing Dutch Irises, various tulips, Grape Hyacinth, paper roses and daffodils, plus a few that I can’t remember off the top of my head. Planting bulbs is a great activity for budding kids who want to help out in the garden, because they are big and easy to handle. Frankie loves placing them in the soil, and he even knows which way they go up! All of this without chemicals and pesticides.