Assisting root growth

We all know that an adequate supply of phosphorus is essential for healthy root growth but, during hot, dry months, we can further assist some of our vegetables to produce extra roots.
Pumpkins produce a huge amount of foliage – too much for the original root system to supply adequate water to the entire vine. Consequently, these plants and some other members of the squash family have evolved to produce roots at nodes (stem joints) along their runners. (See photo below.)
We can assist this auxiliary root formation by carefully lifting the runner and scratching the surface of the soil beneath where roots buds appear. Then cover this with a shovelful of compost and settle the runner back onto the compost. Encouraging extra roots to form will increase your crop.
These sections may be hidden by foliage but it will help to identify them if you place a soft drink bottle or large juice bottle (with the base removed) neck down beside this area. When watering, water not only around the base of the plant, but also into the bottles to supply water directly to the extra roots without wetting the foliage.

Tomatoes in their natural state, grow along the ground and will also form auxiliary roots along their stems, but our method of growing tomatoes tied to stakes prevents this. However, you can give them a helping hand to produce extra roots before planting out by lying potted seedlings on their side when they are 10-12 cm tall. Leave them like this for a week or so, depending on the growth rate, and remember to stand them upright for watering. As you can see in the photo, the main stem with make a 90-degree turn, and root buds will form on the horizontal part of the stem. Plant them out with the growth tip vertical and the horizontal stem just below the soil surface.
You can also hill up soil around tomato plants (a little at a time), and sweet corn plants to encourage extra roots to grow on the lower parts of the main stem.

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Saving pea seed

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Garden peas that we sowed in early May have performed very well again this year and we have been able to freeze quite a lot. We have to net our peas to protect them from birds. We use arches of polypipe supported by garden stakes to hold the netting well clear of the plants, as King Parrots are clever at hooking the pods and pulling them through the netting. Pea flowers are self-pollinating, so netting won’t affect the size of your crop.

We grow our peas in soil with a pH of around 6.5, and we prepare the bed with compost and poultry–based complete fertiliser because peas won’t fix nitrogen unless the suitable rhizobium bacterium has been introduced to the soil. Once the seedlings had poked their heads above ground, we watered regularly.

peasseed However, cropping is almost over. We have left some well-filled pods about half way up the plants to set seed. They produce better seed than those saved at the end of harvest when the plants have exhausted most of their fertiliser supply. We have been saving seed from our peas since 2006, and get good germination without treating our seeds with any fungicide. Pea seeds are easy to save. Select only full sized pods that are full of seeds and allow them to mature on netted plants until the pods are brown and dry as in the photo. Ideally, they should be left of the plants until the seeds rattle in the pods but, sometimes, we have to harvest after pods brown, if rain is forecast. Don’t harvest pods for seed when they are wet, or the seed is likely to go mouldy.

The pods are spread on a fly screen frame, indoors, until completely dry and a fingernail will not make an indentation on the seed. The peas are then shelled and any blemished ones discarded. Seed is hung in an open paper bag for another week before storing in envelopes in an airtight container in a cool place. The benefit of saving your own seed is that it comes from plants that have grown well in your local microclimate.

Winter spinach

spinach One of my favourite vegetables is winter spinach, also known as English spinach. Spinach is rich in vitamins A, C, and E, folic acid, magnesium, iron, fibre, and contains some vitamin B6. It has a more delicate flavour than silver beet and, unlike silver beet, it can be frozen for use during warmer months. Winter spinach loves cold weather and a well-fertilised soil containing plenty of compost. It has a short growing period at our place because warm weather can extend into late autumn, winters are fairly short and mild, and temperatures rise quickly in spring, causing the plants to run to seed. Sow as soon as weather cools in autumn.
Fortunately, this vegetable grows very quickly, and harvesting can begin 8 weeks after sowing seed. From then on, leaves of all varieties of spinach must be harvested every day or two, or the plants will bolt to seed.

Galilee This year, Green Harvest sent to me seeds of their new open-pollinated variety – ‘Galilee’, and it has performed very well in our conditions. ‘Galilee’ was developed in the Middle East and is more tolerant of warm conditions than other varieties of winter spinach. It has produced a lot more foliage than the other variety we grow (‘Winter Giant’) and its mid green leaves have the same flavour as other spinach varieties. It is a great variety for gardeners who have struggled to grow winter spinach.
To freeze winter spinach: I wash the spinach thoroughly, roughly chop the leaves and stems, then put it in a steamer and blanch it with boiling water, before plunging the steamer into icy water. Then drain, and pack into ice cube trays or zip lock bags for freezing. Spinach in zip lock bags is pressed out to a flat sheet on a baking tray for freezing. This makes it easier to break off sections for adding to recipes.

No pods on broad beans

Some gardeners are concerned because their peas are producing pods while their broad beans are not, although the plants are producing lots of flowers.
There is a difference in pollination methods between these two legumes. Garden peas are self-pollinating, and pollination occurs before the flowers open, so failure of pods to form is due either to cold or light frost damaging the blossoms, or the weather being too warm.
According to the Seed Savers’ Handbook, broad beans are partly self-pollinated and partly cross-pollinated, but we have noticed that our broad beans don’t form pods until bees are around. If it is too cold or too windy for bees to be out and about, the flowers die off without forming pods. Broad beans are also reluctant to set pods when the weather is too warm, but if it is still cool enough for peas to form pods, the problem is more likely to be a lack of insect activity. Keep the soil damp and give them a drink of seaweed extract tea. The potassium in that does help fruit/seed production. Oh, and make sure the bed is mulched – apply it early in the morning to keep the soil cooler for them.
There is a theory that removing the growing tips when they start to flower helps pod set. I have tried removing the growing tips on half of the plants and leaving the rest to grow naturally. It didn’t make any noticeable difference to pod setting.
If your broad bean plants haven’t been setting pods, get a medium-sized (about No 5) artist’s paint brush with soft bristles, and use it dry to ‘tickle’ the inside of the flowers to spread some pollen. If that doesn’t produce results, Have a chat with your seed supplier.

When to sow seed

Ian, lIke many other gardeners, is unsure whether he should sow and transplant in the correct moon phase, or sow seeds by the moon phase and transplant anytime, or sow seeds anytime and transplant by the moon.

Over many years of experimenting with moon planting, we’ve found that it is more important to sow seed during the correct phase, than it is to plant out during the correct phase. Seedlings of some varieties of annuals are large enough for transplanting by the time the next correct phase comes around, so it is easy to sow and transplant in the same phase. Others varieties take a shorter, or longer, time to reach transplanting stage, and my advice is that these should be planted out when they are ready, and when climate conditions are suitable, whatever the moon phase. Seedlings sown in a tray will suffer some transplant shock because they often have to be teased apart for transplanting, and these will require some TLC until they become established. However, annual seedlings sown in segmented punnets or individual tubes suffer very little transplant shock and it does not seem to matter when they are transplanted because their root balls are buffered by surrounding mix.

Planting out during the correct phase is important for perennials as strong establishment of the root system is essential for vigorous growth of these plants. This group includes fruit trees and crowns of asparagus, artichokes, herbacous perennials, strawberries, etc., as well as all trees, shrubs and vines.
Most root crop annuals are best sown direct where they are to grow as many don’t perform well when transplanted. If you have to transplant these because mice or ants steal seeds sown in beds, and they are ready to transplant in an incorrect moon phase, just give them some extra TLC. Moon planting gives some extra help in getting plants growing, it is not essential to their survival.

Traditional moon planting is based on observations of farmers for many centuries but very little scientific research has been carried out on why, exactly, certain seeds germinate faster, and grow quickly when sown at particular times, and why cuttings form roots more quickly when taken during Full Moon phase. A brief coverage of this subject on a David Suzuki TV program some years ago stated that fluctuations in sap flow and plant hormones corresponded with the Moon’s gravitation pull, as did subtle variations in Earth’s electro-magnetic field. I think the changes in the electro-magnetic field might be the key to why moon planting works, as plants can only absorb nutrients as water soluble, electrically–charged particles. A serious scientific study of this subject would be most interesting.

Climate zones

Occasionally, I receive e-mails from readers who are confused about which gardening or climate zone they live in. Australia has been divided into as many as eight different gardening zones because of the huge variations in temperature and rainfall across our continent. Altitude variations or geographical features within each zone will modify temperatures and rainfall patterns, breaking up the eight zones even further.
To complicate the issue, climate change is resulting in evolving milder winter conditions in some areas and longer, harsher winters in others. Last summer, extreme heat or rain events played havoc with a lot of gardens across Australia, and the extent of further changes related to extreme weather events is impossible for anyone to accurately predict.
However, Australia can be divided into three basic gardening or growing zones; Warm, Cool, and Temperate (as indicated in the diagram below). The zone divisions are based on the types of plants that will grow in a moderately irrigated garden in each zone
Within these basic zones, altitudes and geographical features gardens at higher altitudes will be cooler than those at sea level in adjoining areas. Sea breezes can provide a milder climate for coastal areas than those a few kilometres inland. Gardens where cold air can flow downwards will be less damaged by frost than gardens in valleys or where solid walls block the escape of cold air. These variations are known as local microclimates, and gardeners may have to make minor adjustments to what they can grow each month according to local conditions, and evolving microclimates brought about by climate change.
New Zealand has a more constant climate and can be divided into temperate and cool zones. Frosts do occur, and snow falls on the mountains, but New Zealand is not subject to hot winds from a parched inland. New Zealand is a very suitable place for growing an extensive range of species from Europe, North America, and the cooler parts of Asia.

WARM CLIMATE ZONES
These are frost free, or may experience some frosts in inland areas during their short winters, and are not suitable for plants that require a defined period of chilling. Warm zones are suited to warmth-loving Australian natives and plants, including fruits and vegetables, from warmer areas of the world. December, January, and February can be too hot for gardening in a lot of warm zones, and some warm zones experience distinct wet and dry periods requiring conventional vegetables and some annuals to be grown at different times to other zones.
The Tropic of Capricorn runs through the northern states of Australia from Rockhampton and Longreach in Queensland, just above Alice Springs in the Northern Territory, and crosses the West Australia coast between Carnarvon and Exmouth. In areas from Rockhampton northwards, tropical coastal conditions allow an entirely different style of gardening, while in drier areas high temperatures and lower water availability make gardening quite a challenge. Winter temperatures in areas within the Tropic of Capricorn can be higher than summer temperatures in some Cool Zones, and common vegetables from temperate areas can only be grown during winter months. Consequently, I have divided this zone into two sub-sections.
Warm zones:
All of Queensland (except for the southern highlands),
Northern Territory,
North coast of NSW above Coffs Harbour,
Northern West Australia,
Northern South Australia.

COOL CLIMATE ZONES
These are areas where low temperatures occur for long periods. Frosts are common in winter and can continue into spring. Snow occurs in some areas. Cool zones are suitable areas for growing many European, Asian, and North American plants that require a period of winter chilling. Many of the fruits and vegetables we are familiar with come from cooler climates. They, and frost-hardy Australian natives, grow well in Australian cool zones, but frost-tender plants, and plants which require a long period of warmth to flower or fruit are unsuitable for these areas.
Australian cool zones:
All of Tasmania, and the ACT,
Southernmost part of South Australia including Mt Gambier,
Around Albany in Western Australia,
Most of Victoria (except for Melbourne and Benalla areas),
Far south coast of NSW,
NSW tablelands and highlands.
New Zealand cool zones:
The interior of the North Island,
The entire South Island.
(However, within these areas, protected local microclimates along the coast as far south as Christchurch can be regarded as cool temperate areas, extending the planting range.)

TEMPERATE CLIMATE ZONES
These, strictly speaking, are all areas on earth between the Polar Regions and the Tropics of Cancer and Capricorn. Although winter frosts occur in some temperate zones, soil warms quickly in spring. The areas of Australia not listed above can be considered temperate zones, because an extensive range of Australian and New Zealand natives, and decorative plants, vegetables, and fruits from temperate regions around the world can be grown in these areas. January to late February can be too hot for a lot of gardening activity in some Australian temperate zones, but mild autumn weather usually extends from March through May.
Minimum temperatures within metropolitan areas of Sydney, Adelaide and Perth are similar and tend to be slightly higher than those in surrounding areas. Melbourne’s minimum temperature is only slightly lower, and gardeners in Melbourne may find that they can grow many temperate climate plants in protected gardens.
On the North Island of New Zealand, North and South Auckland areas, Hamilton, most of the west coast to just above Wellington, the Bay of Plenty area, and the east coast to Hastings are temperate zones.
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Yellow or pale citrus leaves

Autumn is a good time to check your citrus trees for magnesium deficiency. Citrus have a high magnesium requirement and magnesium is essential for the formation of chlorophyll (green colour) in leaves. Without enough magnesium plants will not be able to make sugars and starches, and growth will be poor.
Magnesium deficiency often shows up in citrus in autumn because magnesium is also required for developing fruit and many citrus species produce fruit over the cooler months.
Because magnesium is very mobile in plants, a shortage of this essential element results in magnesium being drawn from the older leaves to new growth. Deficiency shows as pale leaves, beginning with inter-vein yellowing of the outer edges of the oldest leaves, so that a green V remains with the point of the V at the leaf tip, and widest part of the V closest to the stem. In extreme cases, entire leaves may yellow.
Magnesium deficiency can occur in several ways. If soil is too dry roots can’t absorb magnesium, so regular watering of citrus is necessary. It is more common where soil is quite acidic and this can be remedied by watering in some dolomite, which will supply magnesium, plus calcium to raise the pH. If soil pH is in a suitable range for citrus, magnesium deficiency can also occur where heavy rain has leached it from soil, or where excess potassium has been added to soil – this includes use of wood ash, or overuse of seaweed fertilisers, which can cause a build up of potassium.
In these situations, a quick remedy to save this year’s crop is to dissolve some Epsom salts in a small amount of warm water, then dilute it in a full watering can of cold water, and water it into the soil under the outer part of the foliage canopy. You will need about 250 g of Epsom salts for a very young tree, and up to 2 kg for a fully-grown tree.
Magnesium is also important for sweetness of fruit. If your citrus fruits are not as sweet as you would like, it could be due to magnesium deficiency.
However, a general yellowing or paleness of all leaves (chlorosis), while only the veins remain green, could be the result of iron deficiency. Iron deficiency begins in the youngest leaves. This can occur where soil is too alkaline for the tree to absorb iron. If the alkalinity occurred through an accidental overdose of lime or dolomite, the pH can be lowered by adding elemental sulphur to the soil around the tree. If soils are generally alkaline, including some well-rotted cow or horse manure that has NOT had lime added (under mulch, but not dug in) as part of your fertiliser will help reduce the pH by replacing some of the calcium ions in soil with hydrogen ions as it decomposes. To prevent crop losses, it is worthwhile checking soil pH around citrus trees each spring, and correcting it, if necessary.
See also: Feeding citrus

Sowing and planting tip

When sowing seed directly into garden beds, or when planting out seedlings, or planting shrubs and trees, always make sure that soil in the growing area is thoroughly dampened BEFORE sowing or planting. Then, after sowing or planting, you only need to add enough water to settle soil around the seeds or roots. Soil should be what is known as “dark-damp” before you add seeds or plants.
This practice is very important because, if soil in the growing area is relatively dry and you only apply water to the seed row or plants after you put them in the soil, some of the water you apply will be drawn away from the seeds or plants into the surrounding drier soil. The dispersion of water into drier soil is a common cause of germination failure, or seedlings, shrubs and trees drooping several days after planting.
When sowing seed, or planting out seedlings, thoroughly water the furrows or planting holes first. Check that you haven’t just wet the top centimetre of soil. For successful germination, soil must remain dark damp, and a very light application of fluffed-up organic mulch across the growing area or between rows can help prevent water loss through evaporation. Seeds sown in dark-damp soil don’t usually require soaking before sowing, with the exception of silver beet and beetroot as these have a thick, corky outer layer. If legume seeds are sown in dark-damp soil, they do not require soaking beforehand because over-wet legume seeds may rot before germination.
When planting shrubs, trees and vines where soil is not dark damp, fill the planting holes with water and plant only after the water has drained away. After planting, apply enough water to settle soil around the roots and apply a 5-7 cm of organic mulch to prevent water loss through evaporation.

Pruning tomato plants

Jenny has previously not had a lot of luck growing tomatoes and wants to know whether she should prune the side shoots that form on tomato stems.

When growing staked tomatoes, it is common practice to prune the small shoots that form in leaf axils because tomato plants do not have strong apical dominance. That means the leading shoot does not contain a lot of the hormone that prevents side shoots from growing. If left to their own devices, tomato plants produce multiple stems that flop onto the ground, producing additional roots from where stems touch soil. In removing the side shoots (by snapping them sideways when small, or cutting with a sharp knife when larger), growth is concentrated in the lead shoot. A second leader can be allowed to form from just below the first bunch of flowers and, once the plant reaches the top of the stake, you can pinch out the tip of the leaders.
This type of cultivation originated in cooler climates to allow more sun to get to the fruit by removing excess foliage, and make weeding easier. Where summers are hot, plants are better left unpruned once the main leaders are established because fruit can become sun scalded, especially where air pollution is low.
Where summers are very hot, tomato plants can do better under light shadecloth (which reduces transpiration) because it is actually warm air that allows tomatoes to ripen, rather than hot sun. As you know, tomatoes that have started to colour can be ripened indoors, although these will be lower in the anti-oxidant lycopene than vine ripened tomatoes.
Removing side shoots will also increase the size of fruit by limiting the amount of fruit that forms. However, other factors are more important in fruit quality. They are: providing a soil pH of around 6.5–7 because tomatoes will develop blossom end rot if they don’t have access to adequate calcium; providing sufficient well-balanced fertiliser such as mature compost, worm castings or poultry based fertiliser; regular deep watering rather than a daily sprinkle; and mulch to reduce fluctuations in soil moisture.
Just another hint: Plastic plant ties can cut into plant stems. When staking tomatoes, use a piece of knit fabric cut across the stretch, instead. Being more flexible, this type of tie won’t damage soft plant tissue.

Does moon planting work? 2

I thought I’d share with you an interesting experiment with seedlings. The tray on the left was sown during Full Moon phase, which is an incorrect moon planting phase for leafy annuals. The tray on the right was sown two weeks later during New Moon phase.
As you can see the younger seedlings planted in the correct phase have not only had a better germination rate, they caught up with or surpassed the ones sown two weeks earlier. Both were sown in the same seedling mix and received the same amount of care.
In the past, we found this a common occurrence with germinating seed, and always try to sow seed in the correct moon phase for its type.

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