2020

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Have you grown Madagascar Beans? They are delicious! They are a form of perennial climbing lima bean, sweet, buttery and easy to grow. The bean is an attractive white with purple speckles. They are hardy in the sub-tropics, and ours has had three crops in a year so far. I will bring some seeds to the December meeting for all to try.  A few plants is all you need – grow them along a fence or trellis.

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RFC Brisbane Branch newsletter Dec 2000

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The feijoa is in the family Myrtaceae and is a small evergreen shrub with a spreading habit, usually growing to about 4m in height. It was first collected by Fredrich Sellow in the early 19^th century and described in the mid 19^th century and given the name Feijoa sellowiana. In the mid 20^th century it was formally renamed Acca sellowiana (Berg) Burrett as this was deemed to be more botanically correct. However, its original scientific name is still used today. Common names are pineapple guava, guavasteen, and of course, feijoa.

It appears in Glenn Tankard’s Tropical Fruit book (ISBN 0 670 90205 5) but it is definitely not a tropical plant in the true sense. Feijoas originated from the south eastern area of Brazil and Uruguay which is a warm-temperate to subtropical area. This area has generally poor acidic soils and suffers dry periods. However it is important to note that feijoas grow in the plateaus of this area, ranging from 300m to 1,000m above sea level. A French botanist is credited with introducing feijoas to Europe over one hundred years ago, and I understand that all varieties we have today may well emanate from this one source.

Anyone who has eaten a well grown and modern variety of feijoa will marvel at what a beautiful tasting fruit it is. The feijoa is exceedingly fragrant, with a complex flavour. It has a cream-coloured flesh with a distinctive “star” shape when the fruit is sliced cross ways. Quality fruit, depending on the variety, can be up to 200g or more.

Where do you get these fruit? Unfortunately, quality fruit is very difficult to find in Brisbane. The best fruit I have had was grown in Auckland (NZ) – where I lived in the 1980’s. As part of my then job, I was directly involved in registering, under the NZ Plant Variety Rights Act, two cultivars Apollo and Gemini for commercial exploitation. These were selections from a research project to evaluate feijoas grown in home gardens and orchards in the greater Auckland and Northland districts. In my view the best feijoa was Apollo – excellent eating fruit with reasonable keeping qualities. Since this time new improved varieties have appeared.

I have heard people in Queensland say that they do not like the fruit of feijoas at all and from the quality (or lack of it) I have seen here, I would have to agree. Most feijoas have been grown in home gardens producing inedible fruit. The nursery industry to a large extent, have grown seedling plants for sale as ornamentals for the home gardeners. However, there are a number of named varieties you can buy. For further details on varieties available locally visit Daley’s website at: www.daleysfruit.com.au/fruitpages/feijoa.htm .

I have not grown or evaluated the “local” named varieties but am very aware of Triumph and Mammoth. These both originated from New Zealand but over time some clearly have been mis-propagated and therefore are not always true to label. You can guarantee that seedling plants will have poor fruit, even when grown from seed of well-proven varieties. The message is – be careful where you source your plants from. There are very reputable nurseries who do take great care in propagating material.

I am always on the lookout for feijoas especially in the fruiting season. You can find them in all sorts of public places including parks, large ornamental gardens, streetscaping, on university campuses, and corporate gardens. I know of one huge feijoa tree growing in a private property in Tarragindi in Brisbane that must be 50+ years old. Although it has very small fruit it does not appear to be seriously affected by fruit fly – perhaps a potential source of genetic material for plant breeding. Feijoas are grown commercially (small scale) in Victoria and Southern NSW. There is only one commercial orchard I am aware of in Queensland – it is located in Gympie. It was started about 2 years ago by Kiwis with initial plantings of 300 feijoas and a plan to increase this to possibly 8,000 trees. They should have fruit available next season.

Some varieties of feijoa are self-fertile and others require a pollinator, the general rule is plant at least two or three different varieties. The Daley’s web site (see above) will give you good information for each named cultivar. Brisbane does not have the ideal climate and I have found feijoas quite difficult to grow to produce good quality fruit. Feijoas are a hardy plant and apart from them being highly favoured by fruit fly, do not generally succumb to pest and diseases. I have found that feijoas under stress can suffer a fatal form of die back which is symptomatic of phytophthora. They will survive frost. Although they can tolerate drought periods subsequent fruit production is detrimentally affected. To get good fruit the plant needs to be watered deeply; apply superphosphate for flower production (my soil seems very deficient in phosphate); use a good general fertiliser, but do not overdose (I use Nitrophoska Blue TE for all my fruit trees); potash for fruit development; but no lime or dolomite, unless you have highly acidic soils.  I do not use any chemical sprays unless I get really annoyed by the fruit fly. Take note that feijoas are primarily pollinated by birds (I once came across a Northern NSW grower who had planted a few feijoas within a large bird-proof netted area used for stone fruit, and couldn’t understand why he failed dismally to get good fruit set). 

Pruning feijoas is very straightforward. Give them a light prune each year after harvest to avoid excessive spreading and lankiness. Using chainsaws or hedge cutters is OK in my book. This way they will keep a good compact shape and it will not interfere greatly with fruit production. (I like to have plants I can pick the fruit off with out having to climb ladders or use poles). If you leave the plant to grow large and straggly and then hard prune it, you may not see much fruit for a season or two.

Feijoas, depending on the cultivar, ripen from early autumn in Brisbane. They are best touched picked (i.e. hold the fruit in your hand and if it comes away easily from the branch then it is ready to pick – do not yank off) and left for one or two days before eating. Feijoas are not good keepers. The fruit will keep for maybe 10 days in the fridge. Feijoas ripen inside out, and when past their prime or exposed to air the pulp turns a brownish colour with a loss of flavour.

If you want to propagate feijoa plants then the best way is by cuttings taken at the end of the growing season in mid to late summer. Use fresh cuttings straight away; do not let them dry out. Use rooting hormone and put them in a coarse sand and peat type mix. Cover in some form of propagation tent and mist regularly, they will take 2-3 months to strike. They can be grafted with some difficulty, using the whip and tongue method gives best results. Make sure the scion wood is the same size as the rootstock to gain a close fit as is possible on the cambium layers. Grafted trees will generally bear fruit in three years and reach “stable production” in five years.

Feijoas are a healthy choice being low in kilojoules, rich in vitamin C, and are a good source of general vitamins and minerals. The flower petals are very edible and can be used in salads. The native South Americans infused the leaves as a medicinal drink. For the budding enologist – it apparently does make a very acceptable wine. Feijoa pulp can be mixed with ice cream or yoghurt to make a very nice desert.   In fact feijoas can make a good substitute for recipes requiring stewed apples. Use lemon juice to stop the flesh from browning.

A recipe book is available for $9.95 from the NZ feijoa web site at www.feijoa.co.nz – click on “recipe book”. The site also has a very interesting free recipe for how to preserve feijoas for later use.

If you are interested in feijoas there are many web sites you can search on the Internet. A book I would recommend is – Thorp & Bieleski, 2002: Feijoas – Origins, Cultivation and Uses, Hort Research NZ Ltd & David Bateman Ltd – (ISBN 1-86953-503-0).

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This article has been modified for the southern hemisphere.

When we think of lychee trees what we think of is the spectacular evergreen foliage and the clusters of delicious red fruits. What often is not considered is occurring below ground in the root system of the tree. A healthy root system is essential for growing a healthy lychee tree. Understanding how the lychee root system works can help you grow more vigorous and productive trees.

Two Types of Root Systems   Lychee seedlings and grafted trees that have reached maturity have well developed vertical tap roots that can extend a few meters down into the ground towards the water table. These deep dwelling tap roots are accompanied by some lateral branching surface dwelling roots. Air layered trees have no main tap root and instead have entirely shallow lateral branching root systems often called skeleton roots. These skeleton roots have their entire network in the top layer of soil to a depth of about 20cm. The lateral absorptive roots of a lychee tree extend out to about the drip line of the canopy. The diameter of the canopy is a good indicator of the extent of the root system. A clear above ground indicator of a healthy root system is the ability of a tree to resist lateral pressure, such as wind. This is especially true in small trees. Trunks that easily flop from side to side or feel loose, when they are pulled on, are either not healthy or lack an adequate network of roots to support the tree. If some of the root system is exposed, mature healthy roots should be flexible and should display a light green when gently scraped. The smaller branching root tips should be whitish and flexible and should not easily fall apart when tugged. The root system of a lychee tree typically experiences 3 climaxes of growth each year. Not surprisingly, these root system growth events seem to occur when the surrounding soil is warm. They occur from mid-November-December, January-February after harvesting, mid-April when autumn shoots get matured.

How the Lychee Root System Works    A lychee tree has two basic functional systems: the canopy and the root system. It is important to understand the interactions between these two systems and the role of these systems in the health of lychee trees. The canopy, consisting of branches, stems and leaves is where photosynthesis occurs. The products of photosynthesis – sugars and amino acids – are conveyed through the bark to the roots, growing tips of stems and leaves, flowers and fruits. The root system is where water, minerals and nutrients are absorbed from the soil and conducted to all other parts of the plant. Gas exchange also occurs in the root system. The area directly adjacent to the absorbing roots is called the rhizosphere. In a natural, undisturbed forest environment this area is composed of weathered minerals and deteriorating organic matter. Living within this mix are populations of earthworms, insects, diverse invertebrates, protozoa, bacteria and fungi. These organisms participate in the breakdown of organic material into essential inorganic elements that may be used by forest plants. Bacterial microbes break down and solubilize minerals such as phosphorus for plant availability, recycle nutrients and help to protect the plant from soil pathogens and nematodes. Beneficial Mycorrhizal fungi colonize the fine absorbing roots of trees to derive most, if not all, of their food supply (carbohydrates, vitamins and amino acids) from the roots of the plant. In return the mycorrhizal fungi aid in the growth and development of their host tree by significantly increasing the absorptive surface area of the roots, as well as assisting in the decomposition of organic matter. These Mycorrhizal fungi enhance the tolerance of plants to drought, seasonal temperature fluctuations and pH balance as well as minimizing the negative effects of transplant shock. Mycorrhizal fungi also help to protect the plant from harmful diseases and pathogens and reduce the dependency of plants on supplemental fertilizers. In artificial soils, such as what we purchase and use for growing plants in containers or in man-made or urban developed landscapes, these natural soil components are missing and should be replaced for healthy plant growth.

Root shading and cooling:  During late Spring, Summer and Autumn in the sub-tropics the shallow root system of a lychee tree is exposed to the daily cyclical extremes of heating and cooling. This stress is especially pronounced during the mid summer post harvest months. Although lychee trees need partial to full sun, the roots prefer to be shaded for optimum health and growth. The hemispherical habit of growth and shape of the lychee tree naturally keep the root system shaded under the canopy. Mulching provides an excellent way of maintaining a healthy growing environment around the absorbing roots of a lychee tree. Mulch retains moisture, promotes and created a home & food for beneficial soil bacteria and mycorrhizal fungi, earthworms, insects, protozoa and effectively shades the root system from direct exposure to the sun. This helps to regenerate the soil around your lychee tree to approximate forest soil characteristics which are missing in artificial landscapes.

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Jackfruit mature 3 to 8 months from flowering.

A dull hollow sound is produced when the fruit is tapped with your knuckle.

The last leaf of the peduncle yellows.

Fruit spines become well developed and wider spaced and soften.

The spines yield to moderate pressure.

An aromatic odour develops.

Picking time depends on whether the fruit will be used at home or sold.

Fruit intended to be eaten soon should be harvested when the rind is fairly soft, the peduncle leaves turn yellow and the fruit has an aromatic odour.

Fruit intended for sale should be firm with no aroma but the leaf nearest the fruit must be starting to turn yellow and the spines set far apart. The flesh at this stage is crispy and pale yellow.

The quantity of latex decreases as the fruit ripens. Try to cut a fruit that is green and you will have latex all over you. Cut into an over ripe fruit and there is almost no latex.   If you do get the sap on your hands you can easily get it off using lanoline soap, the kind they use in industry.

After ripening, they turn brown and deteriorate rather quickly. Cold storage trials indicate that ripe fruits can be kept for 3 to 6 weeks at 52° to 55° F and relative humidity of 85% to 95%.

You can also make 3 shallow cuts in the fruit a few days before you plan to cut it down which will let some of the latex drain out.

Use rubber surgical gloves and coat knives with olive oil when cutting up the fruit just in case of latex.

If the fruit is too high up to check if it is ripe, slap it with a long pole to hear that dull sound.

Ripening can be accelerated by putting whole fruit into a closed 20 litre bucket 5-7 gallon (20-30 quart)

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Anthracnose is the primary reason why mangoes, avocadoes and some other fruit trees fail to fruit or develop blackened fruit that drops prematurely. Anthracnose is a fungal disease that is exacerbated by rain and high humidity. During dry weather the disease is virtually absent. Application of copper based sprays immediately prior to flowering and during early fruit set and/or use of biodynamic preparations such as casuarina tea can help reduce the effects of anthracnose. Some fruit tree varieties also possess inherent resistance to anthracnose.

Black Spot on Pawpaw

Adequate nutrition is as much a tool in disease control as the use of sprays. Plants deficient in potassium, phosphorous and magnesium are more susceptible to attack by black spot and powdery mildew. Simply increasing the potassium (sulphate of potash and/or lucerne mulch), phosphorous (rock phosphate or chicken manure) and magnesium levels (Epsom salts) helps to make plants more resistant to disease. Pawpaws are most susceptible to black spot disease during the cooler months. Spraying with sulphur or copper based compounds prior to the onset of the cool weather and watering with liquid seaweed can help reduce the severity of infestations.

Citrus Melanose

This disease typically affects more mature trees or plants that have a canopy of foliage that hangs close to the ground. Mulch trees with a feeding mulch such as lucerne. This will help to prevent spores splashing up onto the foliage when it rains. Lift the lower branches so that foliage is well clear of the ground. Spray trees with copper based compounds after all fruit has been harvested, thoroughly wetting the foliage, trunk and branches. Repeat applications each year until no further evidence of disease exists. Improve general tree health with additional nutrients and water.

Damping off Fungus

This disease affects germinating seeds and young seedlings. It is transferred via water and affects the water conducting tissues of the plant. Use new seed raising mix or clean compost. Wash all pots and tools in hot, soapy water then allow to dry in the sun before use. Make sure that plants do not sit in water. There is no cure for affected plants and they should be disposed of so as not to infect neighbouring stock. Note that newly planted seedlings can appear to suffer from a similar condition, but this is typically the result of over watering or planting into a soil containing excessive amounts of fertiliser or overly rich compost and manure.

Passionfruit Virus

At the end of the growing season after production of a bountiful crop, passionfruit vines can look tired and in need of a well earned rest. In some cases, vines will show characteristic mosaic leaf yellowing that indicates presence of a virus disease. Such diseases are often present in plants from an early age, but only begin to gain the upper hand when the vine is occupied with fruit production or stressed in some way. Affected vines may continue to grow, flower and fruit in coming seasons, but will always lack vigour. Unfortunately there is no cure for virus affected plants. Given their rapid growth rate, high productivity and short lifespan, passionfruit vines are best replaced every few years. Unfortunately there is no cure for virus affected plants. Given their rapid growth rate, high productivity and short lifespan, passionfruit vines are best replaced every few years.

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This is a system that uses an open vertical or near vertical pipe to deliver irrigation water to the deep root zone. It encourages a much larger root volume than other forms of irrigation and helps develop a plant that is better adapted to survive after watering is terminated. By delivering irrigation water through deep pipes rather than on the surface, tree roots tend to grow down rather than at the surface which can also benefit any intercropping annuals which tend to be shallow rooted. Weed competition is reduced by avoiding surface irrigation. Deep pipe irrigation works just as well on steep slopes as on level ground.

It is done with 2.5 – 3cm diameter pipe placed vertically 30-50cm deep in the soil near a young tree 2.5-7.5cm away for seedling trees up to 12cm away for larger trees. A screen cover of 1mm mesh can be added to keep animals out. Several pipes can be used for a larger tree if necessary arranged around the tree symmetrically. A series of 1-2mm holes should be spaced 5-7.5cm apart down the side of the pipe nearest the plant to allow water to weep into the soil at all levels (not only at the bottom) to facilitate root growth early on.

If shallow-rooted plants from containers are planted next to a deep pipe without weep holes, the roots may not make contact with the wetted soil. Similarly, a young seedling can dry out if a drip emitter is used to deliver water into the pipe even if it has weep holes. Growing plants in deep containers can minimise these problems.

Deep pipes can be filled from hoses, watering cans or fitted with a drip emitter. If a drip emitter is used then the deep pipe can be smaller (down to around 1cm diameter) and in order to ensure that the water seeps through the pipe at all levels, the drip water rate must be fast enough to fill the pipe or alternatively, the pipe can be tilted with the weep holes downwards so that the water runs over and through them. A battery-powered remote timer combined with a water tank can be set up at a remote site to irrigate once a week which should lead to good tree survival.

The advantages over buried drip systems include ease of access to the drippers in case of blockage.  Deep pipe irrigation can be used with low quality water (though not necessarily with drip emitters if they are likely to block up). The deep pipes can be collected at the end of the season for re-use. Experiments have demonstrated that deep pipe irrigation systems are very effective and more efficient than surface drip or conventional surface irrigation. Much larger effective rooting volumes are developed and the plants are better adapted to survive future dry spells. In very dry regions, long term survival and growth can be improved by including micro catchments to increase effective rainfall by the use of tree shelters to reduce water demand and by the use of mulches.

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In the Western world, Goji berries (Lycium barbarum) are one of the latest fruits to have medicinal claims made for them.  However, these 15-25 mm long red berries have been part of the Chinese herbal medicine for centuries.  Traditionally they have been used to treat inflammation, skin irritation, nose bleeds, aches, pains and as a sedative. They are also commonly used with other botanicals in Chinese medicine for poor vision, anemia, cough and for treating infertility.

Note on nomenclature

Lycium barbarum is known as wolfberries in China and the United States, and as goji berries in Tibet and Mongolia.  Lycium chinense, L. europeaum and Fructus barbarum are synonyms for L. barbarum.  They belong to the Solanaceae family.  They grow wild in these countries but are also cultivated in China.  Bernard King has tasted both the Chinese and Tibetan varieties and much prefers the Tibetan or Mongolian.  He gave me a sample of dried Tibetan goji berries.  They were delicious with a cranberry/sultana like taste.  Highly recommended.  In Tibet, the berries are never touched by hand as they will oxidize and turn black if touched while fresh.  They are shaken onto mats, then dried in the shade.

A note of caution.  It has been made known to me that a related species, Lycium ferocissimum (buckthorn) can be a weed in parts of New Zealand.  Entry of Lycium ferocissimum, Lycium tenuispinosum and Lycium chilense into New Zealand is prohibited.

Medicinal value

 Claims are being made that eating them promotes long life, and in elderly people  increases the effectiveness of the immune system, increases appetite and improves sleep.  Most of the above claims are not backed by peer reviewed medical research.  Yet there are some studies indicating that extracts of goji berries may hold promise in some medical conditions (see below).  Dr Earl Mindell is a driving force behind Western interest in the medical properties of goji berries, particularly their anti-ageing properties, after observing the age of Tibetans and the use of goji berries in their diet.  However, dietary calorie restriction is also likely to a factor in Tibetan diets and are known to increase lifespan, so what are the critical factor(s)?  This is where epidemiological research is essential to determine which factor(s) best correlate with the life span.

Quackwatch (a website set up to assess medical claims) is critical of Dr Mindell, and indicates a number of important errors in his previous published work on herbal medicines.  It states that Mindell claims to hold valid credentials in nutrition. Although he does have a bachelor’s degree in pharmacy from the University of North Dakota, his Ph.D. is from the University of Beverly Hills, an unaccredited school which lacks a campus or laboratory facilities.  The Quackwatch review was written by Dr. Tyler, the Lilly distinguished professor of pharmacognosy (the science of medicines from natural sources) at Purdue University.  On checking the medical literature, I have been unable to confirm claims that goji berries increase immune function in humans (there have been studies on mice using intravenous injections), or stimulate growth hormone release (the so-called “youth hormone”).

On the other hand, one human study has indicated that eating goji berries (50 g per day of dried berries for 10 days) increases levels of an enzyme (superoxide dismutase) which is involved in reducing free radicals in the body, and decreases lipid (fat) oxidation products.  These results are an indication that oxidative stress is reduced by goji berries – oxidative stress is strongly suspected of being involved in ageing and a number of other human diseases.  Another controlled study has shown a decrease in a number of minor symptoms of everyday living such as fatigue and sleeping problems (reviewed by D.S. Burke et al. Current Topics in Nutriceutical Research vol.3 pp. 259-266, 2005).

The Sloan-Kettering Cancer Center in New York summarizes the known medical properties of goji berries.  The bark and the berry contain betasitosterol which can prevent cholesterol absorption in the gastrointestinal tract. Lycium barbarum polysaccharide has been shown to inhibit the growth of leukemia HL-60 cells (a study using cell cultures).  One study reported that in 75 cancer patients, infusion into the blood stream of a combination of  immune stimulation and a  polysaccharide from goji berries improved regression of a number of cancers and improved remission. However, the treatment method used is not standard in Western medicine.  A cerebroside (a type of fatty compound found in the brain and elsewhere) extracted from Lycium barbarum may help protect the liver from damage.

Studies in animals and in human cell cultures indicate that extracts of goji berries have antioxidant activity, enhance growth of immune cells, decrease insulin resistance (improving diabetes), have anti-tumour activity, inhibit damage to the sperm, decrease blood pressure and can decrease damage from a protein thought to be a cause of Alzheimer’s disease.  Most of these studies have been to test the properties of a polysaccharide extracted from goji berries, but these studies do not indicate that eating goji berries will have the same effects.  One of the functions of the gut is to breakdown polysaccharides into sugars, so it is unlikely that the polysaccharide ever reaches the blood stream.  As well, absorption of large molecules such as polysaccharides from the gut into the blood stream is extremely limited.

Goji berries (as do blueberries and avocadoes) also contain zeaxanthin, required for good eye health (a lack of zeaxanthin and lutein are a cause of age-related macular degeneration resulting in blindness).   Claims have been made that they are highly nutritious, with large amounts of Vitamin C, b-carotene (converted to Vitamin A in the body), Vitamins B1, B6 and E, most amino acids required for protein synthesis, minerals, antioxidants (including anthocyanins and other flavonoids) and essential fatty acids.  Levels of these compounds in goji berries need to independently verified and compared with levels in other fruits, as most or all fruits contain antioxidants and other nutrients.  The nutrient and anti-oxidant content may be the most important property of goji berries.

There is much more work to be done before goji berries can be recommended for treating human diseases (so far there appear to be only 3 studies actually using humans).  Contraindicated for people on “blood-thinning” medication (warfarin).

Cultural conditions and availability of plants

Bernard King has Goji berry shrubs for sale (available also through Northern Branch NZTCA).  These are sourced from the Himalayas, either Tibetan or Mongolian (similar properties).  $10 per plant either direct from Bernard or from our branch, cheaper for bulk orders.  The goji berry shrub is a scrambling shrub 2 m high by 3 m, requiring support – perhaps similar to raspberries.  Grows fast with some berries possible in the second year and bearing heavily at 3-4 years.

Patrick Riddall at Awakeri in the Bay of Plenty initially germinated around 600 plants.  This winter he is putting in around 3 to 4 acres of goji berries.   Patrick has supplied the following cultural notes.

The goji bush is a very hardy plant that handles extremes in temperature and will survive just about anything.  Optimum growth is in deep well drained fertile soil in full sun, they go better in full sun than partial sun.  The only thing the Goji bush does not like is having it’s roots sitting in water.  The roots like going deep and do not make good pot plants.  They like regular watering for optimal growth although are very drought resistant once established.  When planting them try to plant them in places were they get frost as this sets the fruit sugars and makes for sweeter fruit (my aside: they will survive –15C; so perhaps fruit from these plants will not be as good in Auckland and north).  Very attractive to caterpillars.

Notes from Sheryl:  This article was taken from the TreeCropper June 2006 – the newsletter of the New Zealand Tree Crops Association www.treecrops.org.nz  A copy is available in our library – kindly donated by Merv Cooper.

The author Gordon Lees will be one of the keynote speakers at the 2007 TreeCrops conference 13th-15th April being held in New Zealand – the program looks exceptionally good. After doing a PhD on cheese bacteria in Melbourne, Gordon spent the next 30 years in the neuro-sciences working in medical institutes then spent the next 27 years at the University of Auckland in the Biochemistry Dept and later in the Depts. of Psychiatry and Pharmacology section of the medical school. He is now retired and is a Research Coordinator for the Tree Crops Association focusing on the medicinal properties of plants. We’re hoping to catch up with Gordon in New Zealand later in the year.

I recently attended the California Rare Fruit Growers meeting in Orange County, California where I got to taste fresh Goji berries. They were large, elongated orange berries – no sweetness in the ones I tried even though the books say they are. They were OK but I’d like to try other varieties. Michael Nave says that in the US they have random seedlings and there is a great deal of genetic diversity in the berries in China – it’s not clear what is being grown in the US. He has been growing goji berries from different sources and the quality of the fruit varies widely. Some are excellent and some are inedible. The dried fruit is promoted heavily on the internet and truth about the origin is often sacrificed in an attempt to get sales. Unfortunately even the alleged organic dried fruit from China is often laced with pesticides and colorants. Goji don’t like hot summers. Once they are established they can tolerate heat but the smaller plants don’t like it at all.

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Nitrogen fertiliser will burn away all your organic carbon in the soil so whenever you add nitrogen fertiliser in any form, you need to add a carbon source – either humic or fulvic acid, or compost at the same time – it helps to balance out – it doesn’t draw out nitrogen out of the soil. Nitrogen is a gas and you want to lock it up in the soil. Having a carbon source holds it into the soil. Just having pure ammonium or even pure fish fertiliser within a day or two, the nitrogen will just evaporate. I use foliar fertiliser in the main growing season when there’s new growth – it’s very weak – do it at regular fortnightly intervals. You’re building your brix levels up. You can feed the trees a lot more and by doing that and spraying small droplets over a leaf, it becomes rapidly absorbed into the tree within an hour or two and you can actually see changes in the plant within 4 hours. When they talk about flushing, it either means putting a lot of fertiliser and a lot of water to get that growth happening. If a tree is healthy it will ward off pests and diseases so keep fertilising small amounts which is better than large amounts as the plant can deal with it a lot better. Use stone mulch about 2½” thick white quartz $40.00 per tonne and paramagnetic basalt fines – $100.00 a tonne. Put the basalt fines down first and the quartz on top then compost around the outer ring of rocks – about 3-4 large shovels per tree and you can put it right up to the trunk. As the tree gets bigger, we can extend the ring of stone mulch. I set up a trial over about 20 different trees and I put a whole lot of different materials down as mulch: different rock sizes/particles, different wood mulches, straw, different types of sand then put the water on and let it sit for a day or two then came back and did the finger test and I was very surprised to see the difference – then when it rained, I did another finger test and its amazing how there’s such a big difference between the different types of mulches. The one that held the most amount of moisture was a combination of large 8ml quartz and very fine basalt rock. We expected other mulches to do a lot better but that one was the most effective for us. I’m an Arborist and can get wood mulch but found it broke down after a year and it had to be reapplied so putting down the stone, it didn’t break down. We found with a lot of other mulches in very dry conditions, it won’t allow penetration of a small shower of rain so if you have wood chips, it becomes a barrier so when the water rains on that spot, it will run off elsewhere. Straw mulch will soak up a lot of water but if you do the finger test, under the soil is still very dry. Some of the growth rates we’ve had by pushing the trees hard – we only had sticks when we started – no more than 300mm – and now after 3-4 months, they are up to chest height so we’re hoping that by the end of the season they will be pushing well over head height and fruiting 2-3kgs per tree so it really helps to do your fertigation through your lines and do foliar feeding. We use NTS products.  An Indian scientist I talked to spoke about having a lot of plant vigour – they believe more in pruning so they push their plants with as much fertiliser and water as possible then they’ll go through and prune very heavily so the plant doesn’t lose any vigour but it will shock the tree and it will then fruit very heavily.

Fertiliser:  With any crop it’s usually applied at the 1^st major flush and there’s usually a window of opportunity from flushing to flowering so during that time, try and push them as much as possible.

Ben grows Jujube at Owen which is on the edge of the desert about an hour north of Adelaide. He imported a lot of varieties from Roger Meyer in California. He thinks a lot of our trees up here in Qld are lacking nitrogen so if your leaves are turning slightly yellow but still have a green vein, then you’ll know to put nitrogen on or if your tree is just sitting there and not doing anything, then push it along with some fertiliser.

Article compiled by Sheryl Backhouse