Full Moon and cauliflower?

It is not surprising that some people don’t take moon planting seriously when TV commercials make statements like “the increased light of the Full Moon has hastened maturation of cauliflowers”.
All vegetables are exposed to light from Full Moons. Maturity times for different varieties of cauliflower vary from 11- 26 weeks, so the slower growing ones would be exposed to more Full Moons than the faster-growing varieties. In fact, radishes, which are sown after the Full Moon, can mature in a month, and would be exposed to the least amount of Full Moon light.
I thought the statement may have been based on the Moon being in Perigee (closest part of its orbit to Earth) and the reflected light from the Full Moon being slightly stronger. However, the only time the Full Moon was near perigee this year was back in January. Cauliflowers require cold weather to form the curd, and the coldest weather normally occurs when the days are shortest and the plants are exposed to less sunlight. It is more likely that the cooler temperatures this year have assisted the early maturation of cauliflowers, and that TV ad doesn’t make a whole lot of sense to me.

Chitting potatoes

If you can get your seed potatoes early, it will help to harden them off before planting, especially if winters are wet where you live. If tubers are kept wet soon after planting, black leg and tuber rots are more likely to occur. The hardening process for seed potatoes involves putting them in a warm well-lit area, out of direct sunlight, for a few weeks. This process is called chitting. If your seed potatoes are large, and require cutting in half before sowing, chitting is highly recommended. Don’t rub cut potatoes with wood ash, as some experts recommend. Wood ash contains a fast-acting form of calcium, and can stimulate the disease that produces “scabby” potatoes.
The segmented parts of cardboard egg cartons are perfect for chitting potatoes. Chitting also allows you to observe whether sprouts on seed potatoes are short and thick, or spindly. Seed potatoes with spindly shoots should be disposed of as they come from plants that have been infected by a virus spread by aphids. Leaves will roll upwards and plants will not produce well.

Potato beds

In temperate and cool areas, it’s time to prepare beds for potatoes, and good preparation can avoid many of the problems that may affect these vegetables. Choose a bed that is well drained and has not grown potatoes (or any of the tomato family) for at least four years to avoid the risk of several soil-borne diseases. Potatoes need a separate area for successful growth, as the plants require regular hilling for good cropping.
Potatoes need plenty of fertiliser, but don’t use fresh manures as the higher nitrogen content in these can reduce tuber production. Avoid adding lime or wood ash either, as potatoes prefer a slightly acid soil. Too much calcium in soil increases the incidence of a disease that produces “scabby” potatoes. A moderate amount of compost or well-rotted manure mixed through the topsoil is excellent. This can be supplemented with an application of poultry-based complete fertiliser or worm castings if compost or manures are in short supply. A drink of seaweed extract tea will help to satisfy potatoes’ high potassium requirement. Make sure the fertiliser is thoroughly mixed through the topsoil to avoid hollow heart occurring in tubers. After preparing the bed, cover it with several centimetres of mulch, and keep just damp until planting time.

Strawberry table?

C & D have asked do strawberries need direct sunlight in order to produce flowers – consequently, fruit? They refer to a segment on ABC’s Gardening Australia program that demonstrated a “strawberry table” where strawberries are planted directly into slashes made in a premium bag of potting medium. C & D are concerned that direct sunlight would cook all the good nutrients out of it the soil in the bag, and ask if dappled shade would be more appropriate.

The answer is this question is that a lot depends on the climate where the strawberries are grown. Some warming of the potting mix could be helpful in areas with a short growing season, such as Tasmania. Or, where strawberries are grown in winter to avoid fungal diseases encouraged by high humidity in summer. However, dappled shade would be more suitable in areas where days can be quite hot while strawberries are growing, flowering and forming fruit, in order to prevent not only cooking the mix, but also the plant roots.
In warm conditions, it is not necessary for strawberries to be in direct sunlight to form ripe fruit. If you observe how strawberries form, each flower cluster sits above the foliage. After pollination, the weight of the developing fruit pulls the cluster downwards until, quite often, the fruit is completely hidden by the foliage, and it reaches full ripeness.
In fact, as soon as our strawberry plants start forming flowers in mid spring, we place a 50% shade cloth canopy over them, positioned high enough to allow good air circulation. Otherwise, fruit not hidden by foliage becomes sunburned and inedible. The canopy also deters birds from eating the fruit. We have also had potted-up spare plants produce sweet, red fruit when grown in our shade house where they only received 50 % light through their entire growth period.
I can see a couple of problems with growing strawberries in a “table”. First, strawberry roots should be fanned out at planting, and this could be difficult to do if you have restricted access to the medium. Secondly, the bag would need holes punched along the underside to prevent the mix becoming waterlogged. Poor drainage will weaken the plants. Also, you would have to slash the bag open when runners start to form if you wanted to increase the number of plants. Strawberry plants should be replaced every two or three years.
If you would like to try this form of strawberry cultivation, avoid using a potting mix that contains a lot of mushroom compost as this is usually heavily limed and strawberries prefer a slightly acid medium. Debco make a certified-organic potting mix that would be suitable for this type of project. It is available from Bunnings stores. Unless conditions are cool, position the “table” where it gets any direct sun early in the day, rather than afternoon, and pack straw around the plants and the bag, if you feel the mix is getting too warm. However, I think growing strawberries in hanging baskets would be easier in warm conditions if lack of space were a problem – and the fruit would be safe from snails and slugs.

Fixing nitrogen

I get very irritated at gardening books and experts which tell Aussie gardeners that peas and beans will fix nitrogen in their garden soil. The theory being that the nodules on legume roots hold nitrogen, and when the roots die off, the nitrogen is returned to the soil for other crops. Some crop rotation patterns and recommendations for fertilising legumes are based on this myth.
Legumes roots require the presence of suitable bacteria in soil to efficiently fix nitrogen in the nodules on their roots. The legume vegetables and flowers we grow originated in the Northern Hemisphere where nitrogen-fixing Rhizobia bacteria occur in soils, but they are not naturally found in Aussie soils; they must be introduced by sowing seed that has been inoculated with a suitable rhizobium. Some groups of rhizobia are effective for several legumes; others are specific to a particular crop. Some crops, such as French beans, require a specific rhizobium that is very difficult to find here, and these will not be able to fix nitrogen effectively.
You can verify nitrogen fixation yourself by gently digging down beside a legume plant to expose some of the roots with nodules. The nitrogen-fixing nodules can be clearly seen on the White Clover roots in the photo below.

Split one of the nodules in half with a thumbnail. If the interior colour is deep pink to dark red, your legumes are efficiently fixing nitrogen and a suitable rhizobium is present in that garden bed. If the interior colour is pale pink, your plants are trying hard, but there is little of the appropriate rhizobium available. If the interior of the nodule is white, your legumes are not fixing nitrogen. (See the close up of the split nodule, below.)

When sowing uninoculated legume seed, you will have to include enough nitrogen in the fertiliser for good growth, and avoid lower leaves of legumes becoming yellow. This occurs when the plant contains insufficient nitrogen or magnesium and the plant draws these elements from the lower leaves to the young tips in an effort to keep growing.

Seaweed in the garden

Over the past week, I’ve been giving both my vege patch and the some of my decorative garden a drink of seaweed tea. Seaweed extract is an excellent supplementary fertiliser. Although it doesn’t contain large amounts of most of the major elements required by plants, it contains a full range of trace elements that are essential in small quantities for healthy plant growth. I apply it when the Moon is waxing, as the increased sap flow during this period ensures quick absorption.
I often recommend seaweed extract tea to gardeners as a treatment for some plant diseases, or when pests are repeatedly attacking plants. Although it is not registered for pest control, the elements in seaweed boost a plant’s immune system and allow it to produce the pheromones that deter pests, making the plant naturally more resistant to a range of diseases and pests. Seaweed also contains a good supply of potassium to strengthen cell walls. Strong cell walls allow plants to resist the effects of drought, frost and saline soils. Seaweed compounds reduce transplant shock, and a drink of seaweed tea before transplanting seedlings, shrubs and trees will assist fast recovery. Other compounds in seaweed, called alginates, are excellent at stimulating the composting process, so the compost heap will also benefit from a drink of seaweed tea.
We use a certified-organic seaweed extract because it is guaranteed not to contain the heavy metals or industrial toxins that can contaminate seaweed collected from beaches. Acadian and Natrakelp are both reliable brands of seaweed extract. It is quite economical to use as the solution is diluted to weak black tea strength for application, hence the name seaweed tea. However, overuse of seaweed in the garden can be counter-productive. Too much potassium in soil prevents plants absorbing magnesium and calcium. But, used in moderation, seaweed is marvellous.

Plant protection

To protect our peas, beans, broad beans and corn from birds, we have to net the beds. We have started using supports made from lengths of polypipe slipped over the ends of metal star stakes, or strong wooden stakes. These arches can be left in position to provide support for netting or shade cloth, as required. Shadecloth will also provide some protection from frost.
Stakes 1.8 metres (6′) in length are suitable for beds that may contain climbing plants or corn. Star stakes measuring 2.25 metres (7′ 6″) can be used for small trees or larger covered areas. For star stakes you will need (2″) 51 mm *** diameter polypipe. Wooden stakes can be used when only (1 1/2″) 38 mm polypipe is available. A semicircular arch is reasonably strong, and this is the easiest to produce for smaller areas.

*** Please Note: Flexible polypipe is still sold in imperial measurements of (1 1/2″) and (2″). Polypipe sold as 50mm diameter is high pressure pipe. It is thicker and less flexible.

This structure over our pea and bean bed was made from 1.8 m. wooden stakes embedded in soil to 30 cm, which is as far as they would go in our soil. This resulted in 1.5 m. of the stakes left exposed. The stakes were positioned on each side of the bed, 1.5 m. apart, with approximately 1.5 m. – 1.8 m. between arches. We used the taller arches here to allow the remaining popcorn cobs to complete drying on the plants. This spacing provided arches with a height of approximately 2.2 m. The structure was erected very quickly and is easy to move if necessary.

To get an idea of the size of the arch canopy you will produce, measure the width of the bed, and divide the measurement by two. Add this measurement to the height of the stakes above the ground. For example, if you are using 1.8 m. stakes, buried 30 cm, you will have 150 cm of stake exposed. If your bed is 1.2 m. wide, half this measurement is 60 cm. Add the two together and you have 210 cm, or 2.1 m. – about 30 cm lower than the average ceiling. If you need a taller arch, use longer stakes.

To calculate the amount of polypipe you will need for each arch, multiply half the width of the bed by 3.1428 (or “pi” if you have a calculator with pi), then ADD 90 cm to allow at least 45 cm to slip over the top of each stake. For a bed 1.2 m. wide, 60 cm x 3.1428 = 188.5 cm plus 90 cm = 278.5 cm. Rounding it off, each length of polypipe would be cut to 280 cm or 2.8 m.

This is an example of a more permanent structure across a series of beds. It is approximately 6 metres wide. The arches are quite flattened and require support in the centre of the polypipe lengths. The gardener has used a strip of flat steel along the centre of the roof, welded to the tops of several galvanised iron pipes set in the ground.

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.

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.