Crop rotation

Crop rotation is the practice of allowing a minimum of three years between growing a particular family or group of plants in the same patch of soil. This practice is essential to maintaining healthy soil because it prevents the build-up in soil of pathogens that cause soil-borne plant diseases. Plants weakened by diseases also attract pests. Many modern farmers have forgotten the importance of crop rotation. The trend is towards monoculture and these farmers have to rely on stronger and stronger chemicals in an effort to cure plant pest and disease problems.
There are eight main groups of plants that are commonly grown in vegetable gardens. Some groups can be grown together but others, such as legumes and the onion family, don’t make good neighbours.
If you find that pests and disease are repeatedly affecting your vegetables, and crops are disappointing, try the crop rotation below and you will find that your garden rewards your efforts. This rotation has six sections and includes a green manure grain, plus a legume green manure if you don’t want to grow your own peas and beans. The green manures are included because they recycle nutrients, replenish organic matter in topsoil, and help inhibit soil pathogens. In this rotation, legumes precede the tomato family because broad beans inhibit a fungal wilt that affects tomatoes. Organic matter assists in keeping soil healthy because it provides a habitat for beneficial microorganisms that keep disease organisms under control and improve soil structure.
Section 1:
Legumes – peas, beans, broad beans, or a green manure legume.
Section 2:
Solanaceous – Tomato, capsicum, chilli, eggplant, pepino, potato. (Some tomato family diseases can also affect Strawberries.)
Section 3:
Crucifers – broccoli, Brussels sprouts, cabbage, Chinese cabbage, cauliflower, horseradish, kale, kohlrabi, mizuna, mustards, radish, rocket, swede, turnip.
Section 4:
Green manure grain – such as barley, cereal rye, corn, millet, oats, sorghum, or wheat – depending on the season. Sweet corn can be grown in Section 4 if you have plenty of compost and don’t need to grow a green manure grain.
Section 5:
Chenopod family – silver beet, beetroot. (Winter spinach can follow a summer crop of beets as long as this group is not grown in the same bed for another 3 years.) Also the Aster group – lettuce, chicory, endive, globe artichoke, Jerusalem artichoke and sunflower.
Section 6:
Umbrelliferous – carrot, celery, coriander, dill, fennel, parsley, parsnip. Also the Allium family – all chives, garlic and onions.

Cucurbits – cucumber, gourd, marrow, pumpkin, rockmelon, squash, watermelon, zucchini. These, except for pumpkin, can be sown with group 5 or group 6, but not both. Pumpkins are best grown on their own because the vines are very vigorous and the roots give off compounds that can deter some other plants. Dill can also be grown with Section 3 to deter cabbage pests. Sweet corn is a good companion for cucumber or beans.

When the legumes are finished, group 2 can be planted in that bed. Group 3 replaces group 2 and so on, with all the groups moving up one bed. If you only have three or four beds, divide some of the beds proportionately, to suit your food preferences. Once your soil is restored to health, you can adjust the rotation to a three or four year one that suits the type of vegetables you prefer to grow, as long as you allow at least three years between the same group.
Crop rotation should also be practiced with flowering annuals and some perennials. Cinerarias and zinnias are related to the lettuce family, petunias are related to the tomato family, and stock and wallflower are crucifers. These plants can succumb to the same diseases that affect the vegetables in that group. Carnations and dianthus can be affected by a wilt disease if they are always planted in the same soil, and carnations, dahlias and irises can also suffer a stem rot disease if crop rotation is not practiced.

More frogs…

It has been raining for the past ten days and I don’t want to seem ungrateful after so many years of drought but, I am anxious to get out in the garden again and get my hands dirty. At least the frogs are thoroughly enjoying the weather.
I really enjoyed visiting the Frogs Australia Network website, as it contains information about an amazing number of frogs, and you can listen to individual frog calls to aid in identification.

Manure tea

As it is Full Moon phase, later this week I will have to brew up some manure tea as a supplementary fertiliser for my lettuce, silverbeet, and spinach seedlings because they have a high nitrogen requirement. Manure tea can also be applied to flowering annuals, cabbage, celery, leeks, also Brussels sprouts that were planted out in February, or earlier.
I usually brew this up during Last Quarter phase as it only takes about a week in warm weather. As the weather has been much cooler than usual for April, the brew will take a good twelve to fourteen days to mature.
Manure tea gets its name from the fact it is applied to soil around plants at weak black tea strength, and around young seedlings as very weak black tea strength because strong fertiliser solutions can burn delicate roots. As it coats the foliage when applied to very small plants, I always water the seedlings after application because it is better to feed the soil than the plant.
Manure, and other fertiliser “teas” are easy to make. For this brew, I place a shovelful of horse manure into an old bucket, and fill the bucket with water. Then I cover the bucket with an old plastic tea tray. The cover prevents loss of nitrogen to the air, and flies laying eggs in the mixture, but a tight fitting lid will usually “pop” because of the gases formed as the manure ferments. The mixture should be stirred every couple of days, will be ready to use during New Moon phase. Sap flow in plants increases as the Moon is waxing, and New Moon and First Quarter are good phases to apply liquid fertiliser because they plants use them quickly.
I strain some of the brew through a piece of old pantihose into a watering can and add enough water to achieve the correct strength for the plants I want to fertilise. After fertilising, the bucket can be repeatedly topped up with water, and the brew can be used until it is quite pale. The residue can be added to the compost heap.
Always wear rubber gloves when handling manure fertilisers. They not only prevent smelly hands, they will prevent the manure coming into contact with any cuts or scratches on your hands.

Pumpkin update

Now that the pumpkin vine is dying off, we are able to find the entire crop – 27 pumpkins from one vine. Compost and plenty of water are the secrets to healthy pumpkin growth. Despite prolonged periods of rain, the vine has remained healthy without a hint of mildew because full access to nutrients has provided the vine with a healthy immune system. The only down side to this luxurious growth has been that it has provided a multitude of places for our chooks to hide their eggs.

Garden seat

Another chain saw carpentry project, this garden seat is one of my favourite spots in the garden, in all seasons. It is situated on the south side of our vegetable patch, under one of the Jacaranda trees that grow beside our driveway. It’s a wonderful place to relax for a cuppa, admire our work and discuss future projects. The seat was constructed very quickly using hardwood from a demolished shed. The “coffee table” was made from a fallen ironbark on our property.

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This unique garden seat was constructed from a fallen tree at a property we visited recently.

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What’s chain saw carpentry?

It is a term my husband uses for various garden projects that are cut out using a chain saw, or where constructions are nailed, screwed or bolted together and the left over bits are cut off with a chain saw (after making sure those pieces are nail-free, of course). More refined DIYers can use a carpentry saw, if they wish. It is a useful method for people who are intimidated by precise woodworking projects, but like to build things. Basically, it utilises imagination and materials that are on hand, or from the building recycling centre. So far, this carpentry method has produced a small frog pond from the lower half of a swimming pool filter drum, a potting bench annexe attached to our shade house, a mobile hen house, and a garden bench and coffee table.

Frog update

Arthur from the Frog and Tadpole Study group (FATS) has informed me that the mottled frogs are “Bleating Tree Frogs”. We have heard these frogs in previous years but had no idea what they looked like. We thought we had lost them when one of our dams dried up during the drought, and our evenings became much quieter, so we are pleased to see that enough survived to restock their species.
Once the majority of the frogs had left the pool, we rounded up the few remaining stragglers and transferred them to our small frog pond. Among the stragglers were this tiny frog, and a similar froglet with a tail. Despite a thorough search of the pool, we were unable to find any more of this variety. I have never seen such a tiny frog before. He is sitting beside a 5¢ piece on the rim of the frog pond.

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Oleander butterfly

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In autumn, caterpillars of the Oleander Butterfly visit my potted Weeping Fig. The Oleander Butterfly has a wing span of 7.5 cm and is very dark brown or black, with white blotches on both wings and body. The caterpillars arrive in an amusing little caravan formation, travelling head to tail, then spent about a week munching on the fig foliage before each forms a chrysalis. I don’t know where they breed because we don’t have any Oleanders, but they seem to enjoy leaves from plants that have milky sap. I leave these creatures in peace because they do little damage to the tree, and the chrysalises are so pretty.

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Red leaves on citrus

Jane e-mailed: I have a question about my lemon tree. I bought a new one and planted it in a few weeks ago, and this week we have had a lot of rain. It has a fair bit of new growth, but the new leaves are red in some places. Is there something wrong with my tree?

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You have no reason to worry Jane, as you certainly have a healthy-looking tree.
Red colouring in new leaves is a common occurrence in plants that have adult leaves with a leathery texture, including avocado, citrus, eucalypts, oaks and roses. The colour is caused by the tree producing red anthocyanins (a type of antioxidant). These are believed to protect the young, tender leaves from ultra-violet light. The leaves will turn green as they toughen.
When citrus produce a lot of new growth as the weather cools, an application to the soil around the tree of seaweed extract at weak black tea strength will build the tree’s resistance to the effects of cold weather. Seaweed contains compounds that strengthen cell walls.

Slaters and earwigs

Slaters and earwigs feed on decomposing organic matter. If they are becoming a pest around your vegetables, you have probably added immature compost or uncomposted manures to your topsoil, or have a lot of semi-decayed organic matter in your soil. We get slaters in our compost heap but we don’t worry about them there as they are contributing to the composting process and dining in the heap keeps them away from the vege patch. Slaters and earwigs are attracted to stressed plants. Give your vege garden and any affected perennials a drink of seaweed extract tea (Acadia, Eco Cweed, or Natrakelp) at weak black tea strength. This will make plants more resistant to pest attack.

Slaters, which are not insects but related to prawns and lobsters, congregate in rotting timber, heaps of rotting vegetation, rock heaps, and shady, dark places. Remove breeding sites from the garden, and turn your compost heap regularly.
Someone told me that they are having great success drowning slaters in beer baits that I recommended in my book for snails and slugs. The slaters are attracted to the yeast smell of beer, as fermenting organic matter has a yeast smell (See post).
Jackie French recommends mixing one part pyrethrum powder to two parts plain flour, and placing baits in, or near, the dark places that slaters shelter in during the day. Try putting the baits in jar lids inside pots laid on their sides with loosely crumpled paper in the top to darken the interior.

Earwigs are slender insects with a set of pincers on the tail end of the body. They can be reddish-brown or black. These little pests will also feed on flower buds and fruit. They like to hide in confined areas in rocks, bark, timber and under debris. Earwigs can be trapped by putting crumpled newspaper into flower pots and leaving the pots on their side in garden beds. In the morning, drop the crumpled newspaper into a half bucket of soapy water to drown the insects, then refill the traps with fresh paper. Remove debris from around your garden to restrict their hiding places. If an earwig refuses to budge when disturbed, it is most likely protecting eggs laid in the soil beneath it. Dig down and dispose of the pale oval eggs.