Most seeds germinate in dark, damp conditions and need to be covered with a suitable depth of topsoil. However, some seeds need light for successful germination.
In the vegetable patch, only varieties of lettuce, Cape Gooseberry, Tomatillo and the Asian greens Seakale and Shiso are ‘light responsive’, but a number of herb and flower species also require light for germination. These include: Angelica, Anise, Arnica, Ashwaganda, Caraway, Catnip, Chamomile, Chervil, Dill, Echinacea, Elecampagne, Evening primrose, Feverfew, Gazania, Lady’s Mantle, Lemon Balm, Mignonette, Rosemary, Summer and Winter Savory, Valerian, Watercress, Wormwood and Yarrow.
Sowing seed for these plants can cause difficulties as the seed is merely pressed into the soil surface and require close attention to prevent them drying, resulting in germination failure. Or, they are scattered on the surface of a punnet where they can be easily washed into clumps at the edge of the punnet despite careful watering.

A way to avoid problems with these seeds is to fill a punnet with damp seedling mix and then cover the surface of the punnet with a single layer of gravel or small pebbles. Then sprinkle the seeds sparingly over the gravel and water very gently, being careful not to flood the surface. The gravel provides crevices for the seed to settle while still allowing them to receive light, and also helps to keep the growing mix damp for germinating seeds.

It is wise to test the pH of compost (including homemade compost) before adding it to your topsoil because the pH of topsoil determines which nutrients are available to plants. Well-made aerobic compost has a pH of around 6.0 to 6.5. Unfortunately, I didn’t follow my own advice recently when, temporarily short of homemade compost, we purchased from our local Bunnings store some bags of Richgro ‘All Purpose Organic Compost’ registered as an allowed input by BFA.

I noticed that the transplanted seedlings where I had applied the compost were not making any growth although the rest of the vege patch was doing well. And, in the area where I had mixed extra compost through each planting hole, the seedlings had turned yellow – a clear sign that the soil pH was too high for the plants to absorb phosphorus for root growth, or iron. Iron (along with nitrogen and magnesium) is essential for chlorophyll (green colouring) formation in leaves that allows plants to produce carbohydrates for growth. Iron deficiency (iron chlorosis) starts in the tips of plants and the leaves of the whole plant turn yellow between the veins or, in extreme cases, white. In contrast, nitrogen chlorosis starts in the older leaves because, when nitrogen is in short supply, plants transfer the available nitrogen to the growing tips, and magnesium deficiency starts in the margins of older leaves.
I tested the topsoil of the affected areas and, finding it above 7.5, I then tested the Richgro compost and the reading was between 8.0 and 8.5. As the pH scale is expressed as negative logarithms, a reading of 8.0 means that the soil is ten times more alkaline than a neutral reading of 7.0. This week I received a question from a blog reader who is having difficulty reducing his soil pH. He had also used the same brand of compost, bought from Bunnings in WA.
Richgro’s response that their “internal records” of the batches in question show a pH of 7.1 and 7.2 and that the test kit I used “do not work well with high organic fraction soils or composts” blah, blah, is not consistent with the physical symptoms of the seedlings. I suspect the problem may have been caused by the type of timber used to produce biochar added to the product. Wood ash contains a very reactive form of calcium and, as the ‘Gardening with Biochar’ website states, “Raising soil pH is biochar’s most important contribution to influencing soil quality“.
* I must add that Bunnings were quite happy to accept return of the unopened bags of compost after I explained the problem.

To test pH
Add equal quantities of topsoil from the bed you are preparing and the compost you intend to use to a clean bucket. Mix thoroughly, then mix again. Test a sample of the mixture according to the instructions on your soil test kit. Ideally, for healthy growth of most plants, the pH reading should be between 6 and 7.2.
If soil pH is higher than this, please see: ‘Changing soil pH’
Also see: ‘What’s soil pH?’

Lovely gardening weather now, in our part of the world. It’s a great time to get the garden organised before chilly winds arrive, and there is lots to do this month in most climate zones.
The following gardening advice is an abbreviated list for vegetables, fruit trees and some culinary herbs that can be planted in May in Australia and New Zealand. A comprehensive monthly guide that includes planting times for the entire garden, as well as when to fertilise, prune, weed, take cuttings or divide plants plus individual cultivation notes can be found in my book Easy Organic Gardening and Moon Planting (Scribe Publications, 2006, 2009 2012) – now also available as an e-book.
* For gardeners who do not use moon planting: sow or plant out any of the following list at any time this month, although you may find germination is weaker when the Moon is in Last Quarter phase.

WARM CLIMATE – South of Rockhampton
Before the Full Moon, bulb fennel, open-headed Chinese cabbage, grain crops, lettuce, mizuna, radicchio, rocket, silver beet (pre-soak seed), spinach, tatsoi, chamomile and coriander can be sown directly into beds, also a green manure crop of barley, cereal rye, chick pea, white clover, faba bean, field pea, cereal rye, Japanese millet, oats, triticale, or wheat. Leek and spring onions can be sown or planted out.
During First Quarter phase, broad beans, and peas can be sown directly into beds.
During Full Moon phase, radish, turnip and garlic can be sown directly into beds, also potato north of Brisbane. Early season onion and watercress can be sown or planted out. Olive trees can be planted.

WARM CLIMATE – Rockhampton and northwards
Before the Full Moon, bulb fennel, open-headed Chinese cabbage, grain crops, lettuce, mizuna, radicchio, rocket, silver beet (pre-soak seed), spinach, tatsoi and coriander can be sown directly into beds, also a green manure crop of barley, cereal rye, lablab, oats, or triticale. Fast-maturing celery, headed Chinese cabbage, leek, silver beet, spring onions, parsley, and chamomile can be sown or planted out.
During First Quarter phase, bush and climbing beans and peas and sweet corn can be sown directly into beds, and pumpkin, rock melon, summer squash, tomato, watermelon and zucchini can be sown or planted out.
During Full Moon phase, beetroot (pre-soak seed), carrot, radish and swede can be sown directly into beds, and evergreen trees, shrubs, and vines can be planted.

TEMPERATE CLIMATE
Before the Full Moon, open headed Chinese cabbage, lettuce, mizuna, spinach and tatsoi can be sown directly into beds, also a green manure crop of faba (broad) bean, field pea, barley or oats. (Cereal rye can be sown in frost-free areas.) In frost-free areas, grain crops, lettuce, radicchio and spring onions can also be sown or planted out.
During First Quarter phase, fast-maturing broccoli, broad beans, peas and chamomile can be sown directly into beds in frost-free areas. In frost areas, delay sowing broad beans and peas until June. Although the plants are frost-hardy, the flowers are not.
During Full Moon phase, radish, turnip, and garlic can be sown direct, and early season onion can be sown or planted out. In frost-free areas, strawberries can be planted out.

COOL CLIMATE
Before the Full Moon, suitable lettuce and spinach can be sown directly into beds, also a green manure crop of faba (broad) bean or field pea, oats, or triticale. Spring onions can be planted out.
First Quarter phase: broad beans and peas can be sown directly into beds in late May. Avoid sowing broad beans and peas too early in frost areas. Although the plants are frost-hardy, the flowers are not.

During Full Moon phase, radish can be sown directly into beds, and early and mid season onion can be sown or planted out. Garlic can be sown in warmer areas, and raspberry and currants can be planted from mid May.

Some gardeners may not be sure whether they are in a Temperate or Cool climate and, where frosts occur, the position of a property within a neighbourhood (the microclimate) can affect how much frost may affect your garden. The diagram below indicates where frost is more likely to affect parts of your garden.
The position of garden beds can also have a marked effect on the amount of plant damage that frosts cause. Cold air, like water, always flows downwards; anything that blocks the downward flow will result in frost damage in that area. Buildings, solid fences and shrubbery, and flat land at the bottom of a slope can all allow cold air to pool, and plants in these areas are more likely to be damaged by frost.

In temperate climates areas that can be affected by frost, gardeners may find it helpful to use the guide for ‘cool climates’ in autumn and winter and use the ‘temperate climates’ guide in spring and summer because the world’s climate is changing and we have recently experienced harsher winters and hotter summers. It appears that the standard climate zones may have to be adjusted slightly in future. If unsure about what to plant at a particular time of year, a reputable local nursery will have suitable plants in stock and be able to advise you on what is best for your local microclimate. Be cautious though when buying seedlings from Australia-wide nursery chains, as some tend to send the same seedlings to stores in all climate zones.

By the way, advice to orient beds in a north/south direction to allow plants to receive ample sunlight comes from northern hemisphere gardening practices and only applies to very cool climates in Australia. Most areas of Australia get more than enough sun to ripen crops. In fact, plants can benefit from some relief from harsh afternoon sun in warmer climates during summer months. It is more important to position beds across any slope in the ground to ensure that all plants in a bed have equal access to water. Avoid placing vegetable garden beds under trees, as trees are very competitive for both moisture and nutrients.

There’s lots to do in both the vege patch and more decorative parts of the garden in April and the slightly cooler weather makes the work a bit easier.
The following gardening advice is an abbreviated list for vegetables, fruit trees and some culinary herbs that can be planted in April in Australia and New Zealand. A comprehensive monthly guide that includes planting times for the entire garden, as well as when to fertilise, prune, weed, take cuttings or divide plants, can be found in my book Easy Organic Gardening and Moon Planting (Scribe Publications, 2006, 2009, 2012, also now available as an e-book).

* For gardeners who do not use moon planting: sow or plant out any of the following list at any time this month, although you may find germination is weaker when the Moon is in Last Quarter phase.

WARM CLIMATE – South of Rockhampton
Before the Full Moon, cabbage, headed and open Chinese cabbage, grain crops, lettuce, mizuna, radicchio, rocket, silver beet (pre-soak seed), spinach, tatsoi, coriander, and nasturtium can be sown directly into beds, also a green manure crop of, chick pea, white clover faba bean, field pea, cereal rye, Japanese millet, oats, triticale, or wheat. Celery, leek, spring onions, parsley, bulb fennel and chamomile can be sown or planted out.
During First Quarter phase, broad beans, fast maturing broccoli, peas and nasturtium can be sown directly into beds.
During Full Moon phase, carrot, garlic, radish, swede and turnip can be sown directly into beds, and early-season onion, mint, rosemary, thyme and watercress can be sown or planted out. Globe artichoke suckers, lemon grass, strawberries, pineapple, and evergreen trees, shrubs, and vines can be planted.

WARM CLIMATE – Rockhampton and northwards
Before the Full Moon, cabbage, headed and open Chinese cabbage, grain crops, lettuce, mizuna, radicchio, rocket, silver beet (pre-soak seed), spinach, tatsoi, coriander, and nasturtium can be sown directly into beds, also a green manure crop of cereal rye, lablab, Japanese millet, oats, or triticale. Celery, leek, spring onions and parsley can be sown or planted out.
During First Quarter phase, bush and climbing beans, fast maturing broccoli, peas, and nasturtium can be sown directly into beds, and cucumber, pumpkin, rock melon, summer squash, tomato, watermelon and zucchini can be sown or planted out.
During Full Moon phase, beetroot (pre-soak seed), carrot, parsnip, potato, radish and swede can be sown directly into beds, and lemon grass, strawberries, pineapple, dandelion and oregano can be sown or planted out. Evergreen trees, shrubs, and vines can be planted.

TEMPERATE CLIMATE
Before the Full Moon, bulb fennel, cabbage, headed and open Chinese cabbage, grain crops, lettuce, mizuna, radicchio, rocket, spinach, tatsoi and coriander can be sown directly into beds, also a green manure crop of faba (broad) bean, field pea, barley, cereal rye, oats, triticale, or wheat. Chickpea can be sown in frost-free areas. Leek, spring onions, chamomile and parsley can be sown or planted out, also silver beet (pre-soak seed) in frost-free areas.
During First Quarter phase, broccoli can be sown directly into beds, also broad beans and peas in frost-free areas.
During Full Moon phase, radish, swede turnip, turnip, and garlic can be sown directly into beds, and early season onion can be sown or planted out. Globe artichoke suckers, strawberries and lemon grass can be planted, also evergreen trees, shrubs, and vines during first half of April.

COOL CLIMATE
Before the Full Moon, grain crops, lettuce, spinach can be sown directly into beds, also a green manure crop of faba (broad) bean, field pea, oats, or triticale. Leek can be planted out.
Avoid sowing broad beans and peas too early in frost areas. Although the plants are frost-hardy, the flowers are not.
During Full Moon phase, radish and turnip can be sown directly into beds, and early season onion can be sown or planted out. Swede and garlic can be sown in warmer areas, and raspberry and currants can be planted in cold areas.

Scientists may have found the answer to ‘colony collapse disorder’ that has caused a severe reduction in bee populations. A bee shortage has serious implications for the world’s future food supply for the many crops that require pollination by bees. See:
Pesticides short-circuit bee brains: study

I will be giving a talk about organic gardening at 10 am at the Wingham Farmers Market on Saturday April 6th.

If you are in the area, come along and find out how easy it is for you to make your entire garden healthier and more naturally resistant to pests and diseases.

Wingham Farmers Market is a great source of fresh local produce.

The market is held on the first Saturday each month from 8 am to noon at the Wingham Showground in Gloucester Road.

Snake beans are a good value crop for the vege patch where summers are hot, and French beans may struggle. They are prolific croppers and 3 plants are probably sufficient to supply a family of 4 through warmer months. A popular ingredient in Asian dishes, they can be substituted for French beans in many recipes. Snake beans can grow up to half a metre or longer but tend to become a little tough if allowed to grow to this length (i.e. the beans at the top of the photo). They are best eaten when 30 – 40 cm in length while they are young, tender and flavoursome. Pods grow fast and should be picked every day, or every second day at least, to ensure that they are harvested at their best, and to keep the vines forming new pods.

Snake beans take up very little space in the garden as they are grown on a trellis in soil that has plenty of compost added, which should keep the soil pH at an ideal level (6.5–7). In late spring, when soil temperature is at least 15 degrees Celsius, sow seeds in damp soil 1 cm deep and 30 cm apart. Do not water the soil again until seed leaves appear, then water regularly to ensure healthy growth. In tropical areas where summer rainfall is heavy, sow seeds in hills to improve drainage. Seeds germinate quickly, and vines can produce pods in 60 days in very hot weather.

An equinox marks the day when the Sun crosses the Equator and both day and night are of equal length. Today is our autumn equinox. From now on, days in the Southern hemisphere will gradually become shorter until the winter solstice on June 21st, the shortest day of the year.
Daylight Saving Time will end in New South Wales, The Australian Capital Territory, South Australia, Tasmania and Victoria on April 7th.

Australia has experienced the hottest summer on record with bush fires in the west of the country and, in NSW and Queensland, a repeat of last March’s very wet weather. Avoid gardening in water-logged soil, as it will only damage soil structure and make it easier to spread soil-borne diseases. If conditions are suitable for gardening and you have a garden bed that you are not using for a couple of months, consider growing a green manure crop to add organic matter to your soil. Organic matter in topsoil insulates plant roots from soil temperature fluctuations, improves both moisture content and drainage of soils, and allows plants to be more resistant to adverse climate conditions
Triticale is good for reclaiming waterlogged soils, and wheat can handle heavy soils and semi-arid conditions. Oats grow quickly and add lots of organic matter to soil.
The following gardening advice is an abbreviated list for vegetables, fruit trees and some culinary herbs that can be planted during March in Australia and New Zealand. A comprehensive monthly guide that includes planting times for the entire garden, as well as when to fertilise, prune, weed, take cuttings or divide plants, can be found in my book Easy Organic Gardening and Moon Planting (Scribe Publications, 2006, 2009, 2012, also now available as an e-book).

* For gardeners who do not use moon planting: sow or plant out any of the following list at any time this month, although you may find germination is weaker when the Moon is in Last Quarter phase.

WARM CLIMATE – South of Rockhampton
Before the Full Moon, bulb fennel, cabbage, headed and open Chinese cabbage, grain crops, lettuce, mizuna, radicchio, rocket, silver beet (pre-soak seed), tatsoi, chamomile, coriander, nasturtium and sunflower can be sown directly into beds, as well as a green manure crop of strawberry or white clover, Japanese millet, oats, field pea or triticale. Celery, leek, spring onion, sweet basil and parsley can be sown or transplanted.
During First Quarter phase, broccoli, bush and climbing beans and peas can be sown directly into beds, and tomato and zucchini and can be sown or transplanted.
During Full Moon phase, beetroot (pre-soak seed), carrot, parsnip, and radish can be sown directly into beds, and cauliflower, early season onion, swede turnip, turnip, lemon balm, lemon grass, marjoram, oregano, rosemary, thyme and watercress can be sown or transplanted. Globe artichoke suckers, strawberries, avocado, citrus, olive and pineapple can be planted.

WARM CLIMATE – Rockhampton and northwards
Before the Full Moon, nasturtium and sunflower can be sown directly into beds, as well as a green manure crop of Japanese millet, lablab, oats or triticale. Cabbage, leek, silver beet (pre-soak seed), spring onion and chamomile can be sown or transplanted.
During First Quarter phase, broccoli, and bush and climbing beans can be sown directly into beds, and capsicum, cucumber, egg plant, pumpkin, rock melon, summer squash, sweet corn, tomato, watermelon and zucchini can be sown or transplanted.
During Full Moon phase, beetroot (pre-soak seed), carrot, parsnip and radish can be sown directly into beds, and lemon grass and oregano can be sown or transplanted. Citrus, pineapple and strawberries can be planted.

TEMPERATE CLIMATE
Before the Full Moon, bulb fennel, cabbage, headed and open Chinese cabbage, grain crops, lettuce, mizuna, radicchio, rocket, silver beet (pre-soak seed), tatsoi and coriander can be sown directly into beds, as well as a green manure crop of red or strawberry clover, faba bean, field pea, barley, cereal rye, oats, triticale or wheat. Leek, silver beet (pre-soak seed), spring onion, chamomile and parsley can be sown or transplanted. In warmer areas, celery and chickpea can also be sown. In colder areas, also sow English spinach and sow Brussels sprouts directly into beds.
During First Quarter phase, cauliflower can be sown directly into beds, and broccoli can be sown or transplanted. In warmer areas, peas can also be sown directly into beds.
During Full Moon phase, beetroot (pre-soak seed), carrot, radish, swede turnip and turnip can be sown directly into beds, and early season onion, globe artichoke, lemon balm, marjoram, rosemary, thyme and watercress can be sown or transplanted. Globe artichoke suckers, strawberries, avocado, citrus and olive can be planted. In warmer areas, parsnip, mango, and pineapple and oregano can also be sown or planted.

COOL CLIMATE
Before the Full Moon, headed and open Chinese cabbage, grain crops, lettuce, mizuna, English spinach and tatsoi can be sown directly into beds, as well as a green manure crop of clover, faba bean, field pea, cereal rye, oats, triticale or wheat. Leek and spring onion can be sown or transplanted. In warmer areas, cabbage, radicchio, coriander and rocket can also be sown.
During First Quarter phase, suitable broccoli can be sown or transplanted in warmer areas.
During Full Moon phase, radish, swede turnip, turnip and garlic can be sown directly into beds, and strawberries, mint and watercress planted.