Tuesday, August 31, 2010


This morning I noticed a crow in our alternate chook run where our 2 new ducks are living. It seemed a bit odd and on closer inspection it was unable to fly.
After catching (using my fish net) I noticed a large tick embedded in it's neck.
This has been removed and we are keeping it for a few days in the chicken tractor
to see if it survives. It is eating grain quite well this afternoon and seems healthy enough.

Some produce : Kohl Rabi Cabbage and Broccoli. One of the cabbages has split.

Fennel in flower and a Brassica sp (not sure which one) that the native bees are
loving at present.

Biochar - 2 drum method

There's a lot on the internet about biochar being really beneficial for soil fertility and as a way of removing Carbon from the atmosphere. The basic science seems to be that the charcoal provides " habitat" for the soil organisms and also helps prevent the leaching of nutrients by heavy rain.

One of the waste products here is palm fronds- they hang around seemingly forever without rotting and, as they are so bulky, they make the yard look untidy (not that we try and have a "show garden" ). My solution is to use them to make biochar that I then dig into the vegetable garden.

I use the 2 drum method as it is simple and effective. The outer drum is an old 44gal drum and the inner is an old galvanised rubbish tin. I cut up the fronds and pack as much into the rubbish tin as I can - stomping it down to fit more in. It is then stood upside down inside the 44gal drum and more palm frond pieces , bits of wood are packed around this and then it is lit. After it is obviously burning, the lid goes on. The idea of the chimney ( a piece of 90mm galvanised stormwater pipe) is to create draft and thus more heat. When the contents of the rubbish tin heat up, they release wood gas which ignites as it escapes from underneath, thus increasing the heat even more. I have used other methods to make biochar but this is the easiest and most effective albeit in small quantities.

I have put several batches onto the vegetable garden and did a small trial of lettuce and beetroot with and without biochar ( a row with some in the bottom of a shallow trench and another row without) The lettuce was definitely better with the biochar underneath. The beetroot was much the same but I suspect the pH was wrong for this plant in this part of my vegetable garden.
Comment on the Internet is that it takes a couple of years to really work well, and it seems to need to be "activated" by soaking in a fertiliser solution.

It is a good way to recycle palm fronds into something more useful even if it does not have a dramatic effect. My double drum system is really cheap to make although it will probably rust out fairly quickly.


Sunday, August 29, 2010


Coming back from the garden club meeting yesterday at Willow Vale we noticed several fields covered in a blue flowering weed.This is also common on our property and is called Blue Billygoat weed. Although we do not eat it, when we attended an edible weeds talk at the Nambour Garden Expo a few months back the presenter did indeed mention that she considered it edible.

Binominal name : Ageratum conyzoides
Common name : Blue Billygoat weed

Identification :

This plant comes from Mexico/Central America and there is several cultivated varieties as a bedding flowering plant. It is a herb to about 1 m with blue/mauve flowers. Leaves are ovate or triangular and are about 5x7cm in size. When the leaves are crushed they emit an aromatic mint scent ( this chemical has been identified as eugenol)

Traditional use :

Cribb in Wild Medicine in Australia records that it is used for "cuts, sores and fever" in Malaysia and Indonesia (ref 1). It has also been used as a tea for colds and flu in China.
Traditional use also includes diabetes and indeed a rat model of diabetes does show reduction in blood glucose levels (ref 2)

Pubmed search (Search term: Ageratum) :

abstract 1: essential oils from Ageratum had some antibacterial effect but NOT against 2 common human pathogens ( E Coli and Staph)
abstract 4: Forty cows died after grazing on Ageratum in Mexico . At autopsy, haemorrhages were found in joints, muscles and internal organs ( heart,liver and kidneys). Chromatography revealed coumarins,alkaloids and triterpenes. The coumarins are what would have caused the internal bleeding ( coumarin = warfarin which is what is used in humans to prevent clotting and it needs to be carefully monitored).
abstract 7: This study reported finding 4 pyrrolizidine alkaloids in Ageratum. These are not good to be eating as they cause liver damage and cancer long term.

Apparently this plant deters insect attack by way of a chemical that interferes with metamorphosis. It certainly seems to be left alone by insects on my property.

Conclusion: Although some may consider this an edible plant I do not, until there is much better evidence to the contrary. Indeed, having pyrrolizidine alkaloids and coumarins makes me even more wary.


ref1:Cribb Ab and JW : Wild Medicine in Australia : 1981 Fontana/Collins pg158
ref2: http://www.bioline.org.br/pdf?tc06039

Still busy preparing for a medical conference presentation soon

Thursday, August 26, 2010


Choko is a very successful plant for us providing lots of pear shaped and sized fruits over the past few months. It is starting to die back now (late winter)

binomial name : Sechium edule
common name : Choko or Chayote

There are several varieties - the common is green but we have a white variety courtesy of another member of our garden club - Tamborine Sustainable Gardeners Society. One of the benefits of belonging to a garden club is the sharing of plants and knowledge. We have acquired our Yakon, Water chestnuts and Queensland Arrowroot this way.

This plant has come from Central America and no doubt has been eaten by humans for a long time. There is an excellent resource on the Internet about the foods of the Incas that I would recommend - google : Lost crops of the Incas will find it ok. It is really surprising how many of our foods have come from Central and South America ( Yakon and Arrowroot are included). This is a free online book and I found it so interesting I purchased it from Amazon.

Choko has had a bad reputation in Australia and New Zealand - as kids we had to eat it and most found the taste disagreeable and indeed today we meet people who refuse to eat it as adults. We don't mind the taste , it is really quite bland and as we have had excess fruit we have bottled some with apple juice and orange juice as the flesh of it takes up flavours from other sources. Anne has made choko pie with apple flavour and served it up to guests who did not realise it was not apple. We ate it tonight as a boiled vegetable along with pumpkin and some salad greens

The leaves and roots are eaten in other parts of the world (asia) but we have only eaten the fruit.

Pubmed search (search term Sechium edule)

One abstract indicated that an extract of this plant had a vasodilatory effect ( that would result in blood pressure lowering ) and anti-oxidant activity (abstract 1). This blood pressure lowering effect was confirmed in another study ( abstract 14) Another abstract (number6) was difficult to understand but it seems to imply that Choko has a beneficial effect on the metabolic byproducts of diabetes that cause the complications seen in that disease.

Other internet sites (wiki) indicate that it contains Vit C and some amino acids. How much per serve of 100gm I am unable to find. There is about 80kJ/serve.

Conclusion - this plant grows well for us and we will keep it going! It is tough and non demanding although it does die right back in summer here


Monday, August 23, 2010

Fraser Island Creeper

A couple of photos from yesterday afternoon

The first is Tecomanthe hillii
Common name of Fraser Island Creeper or Pink Trumpet vine.
It is growing on a wire frame to help hide 2 water tanks near our driveway.The trumpets are quite spectacular

The other is of an Azalea in bloom. Azalea foliage here gets decimated with lacebug but they flower regardless.

Sunday, August 22, 2010


This is NOT an edible weed although it has been used historically for various medical problems.

Binomial name : Conyza canadensis or Conyza bonariensis

Common name : tall fleabane, flaxleaf fleabane, asthmaweed

Conyza is derived from the Greek word Konops meaning flea and bonariensis from Buenos Aires in Argentina where this plant may have originated from. The canadensis is self explanatory.
The common name fleabane is named thus as the ground seeds of the plant are supposed to have a flea repellant effect, although Culpepper (1653)wrote that it obtained it's name because the seeds looked like fleas.
When I discovered the name for this weed recently I just had to research it -the common name is intriguing. It is very common on my property and now I know why - seed production per plant is upwards of 120,000! As the name indicates it comes from the Americas but is now cosmopolitan.


Fleabane is an annual weed with a single stem to about 1-2m - C bonariensis has lateral branches from near the top of the main stem that overtake it whereas C canadensis tends to be unbranched. There are also differences in hairs on bracts ( bracts are the scale like leaves at the base of a flower) I am reasonably certain that I have the latter variety - I tend to pull it out before it gets too tall and thus have not closely examined the stalk. The lower leaves droop and look half dead, the other leaves have a slightly hairy feel and look.

Uses :

Historically it was used in the treatment of diarrhoea and haemorrhage and applied externally for skin infections

Pubmed search:

search term Conyza bonariensis :
abstract 5 : essential oils from CB showed an inhibition of the inflammatory reaction and nitric oxide production in a mouse model abstract 7 :3 glycosides from CB had a weak inhibitory effect on xanthine oxidase
My comment on this is that chickweed seems better for this latter effect.

search term fleabane
abstract 10: Erigeron (old name) annuus extracts had some potent inhibition of some diabetic metabolic products and pathways. The idea being that these result in the diabetic complications seen regularly clinically and if they can be blocked it may help prevent such occurring.

search term Conyza:
abstract 19: C canadensis extract showed strong inhibition of platelet aggregation.

Now this runs contrary to the traditional use of stopping haemorrhage or bleeding!

Conclusion :

Not a weed I will be using until there is better reason to do so. Some interesting early findings on the seach for novel compounds to help treat diabetic complications.

Saturday, August 21, 2010

Cape gooseberry

Glorious day in SE Queensland. We spent several hours in the vegetable garden and collected our first harvest of cape gooseberries. Pulled out some radish plants that had got way to big. Planted some more carrot, beetroot,lettuce and moved the wire frames for tomatoes to a new spot. pH tested ok at about 6.5.

Dinner menu - jade perch fillets in batter
tatsoi leaves, pumpkin and spring onion
desert of stewed cape gooseberries and cream

The main ingredients are home grown

Thursday, August 19, 2010

Garden - general

Still busy preparing for a medical conference presentation, but at least I had my usual days off this week.

Committee meeting for our Garden Club this morning, but managed some time in the yard this afternoon. Mainly watering the vegetables and doing my weekly folar type fertilising that has seemed to make a big difference this year. Anne was also planting and watering flower seedlings in preparation for a visit by a different garden club next month.

Citrus trees don't do well here, I'm not sure exactly why, but I persist as we like to eat grapefruit, oranges etc.

Today I applied some epsom salts and potash to 2 citrus trees with leaf signs of deficiency . Time will tell if I got the right diagnosis! Even though the leaf signs are different I applied the same mixture to both.

Also picture of our mulberry tree developing fruit - it is the standard variety but quite sweet (black when ripe). We have the white shatoot variety as well but it is still small and probably won't have much fruit on it this year.

I still have some more edible weeds to work up but there is other priorities at present.


Saturday, August 14, 2010


Anne and I have Cinnamon each morning on our breakfast - a few generous shakes from the container ( along with some diced up leaves of herb robert and gotu kola)

The reason we have Cinnamon is as follows:

(Pubmed articles - search term Cinnamon )

#2 Cinnamon may help prevent colon cancer by activation of protective responses in colon cells.
#4 Cinnamon causes an increase in the death of cancer cells and inhibition of tumour cell spread in a mouse melanoma model.
#11 In a diabetic mouse mode, it has an effect of lowering blood sugar, lowering triglycerides and cholesterol, and increasing the level of ldl ( the good type of cholesterol).
#13 Cinnamon seems to regulate certain genes in the adipocyte (fat) cells, causing them to take up and store less fat.
#16 It improves insulin sensitivity, and decreases fat storage in rats fed a high fat/ high fructose diet ( ie typical american diet!)

It really is a worthwhile addition to your diet for these reasons - and it doesn't taste too bad either!


Big day in the garden today - glorious weather in SE Queensland - mid 20s temperature. Planted lots of Lomandra longifolia - we had lots of small ones that had been growing near a mature clump. It is an excellent hardy native plant.

Thursday, August 12, 2010

Fruit fly netting

As we live in SE Queensland near the coast we have an ongoing battle with fruit fly. This native fly stings developing fruit and lays an egg that hatches into a maggot that spoils the fruit as it ripens.

We have tried different ways of combating this fly (but not spraying, as we are against using such chemicals in our yard). Over the years we have tried the pheromone traps and a laced ( spinosad) protein lure with modest success.

However the best solution seems to be netting.

This solution was shared with us via a member of a garden club we belong to - Tamborine Sustainable Gardeners Society.


Star pickets - mine are 1.8m from memory
50mm rural b poly pipe - green stripe
Fruit fly netting

Be careful buying the polypipe - it needs to fit over a star picket. I bought some 50mm blue stripe and it didn't fit easily and I then had to use some old galvanised pipe instead.

Hammer the star pickets in - clearing each corner of the fruit tree
Place poly pipe over 2 star pickets to create a hoop over the tree and repeat for the other 2 star pickets. Tie at top to stabilise.

This creates a frame over the fruit tree. This can stay in place and be adjusted if needs be, depending on the growth of the tree and pruning.

After pollination has occurred throw over the netting- I use a leaf rake to manoeuvre the netting especially to get it over the top of the hoop.

As fruit flies fly down to sting the fruit it is not too important about securing the bottom. However, I also have had a problem with rats eating the fruit and now use logs/timber around the base to try and exclude them. Last year, in desperation, I even tied up our dog (in a temporary kennel) nearby to scare them away as the were chewing through the netting to get at the fruit.

I can't advise about where to get ff netting as we got ours via our garden club including some at the right price (ie no cost!) as it was storm damaged and needed minor repair ( fix any holes with a darning needle and fishing nylon).

After harvest I remove the netting and store it away for reuse.


Less posts next month as I have to prepare a presentation at a conference I am attending - probably only 1post /week. Posts to come on dandelion , mallow and then some non edible weeds but interesting though.

100mm rain yesterday - water tanks overflowing

Tuesday, August 10, 2010


Picture of our Jap Pumpkins I harvested yesterday - they needed to be picked for storage as the possums were getting into them. According to one of my elderly patients, they are named Jap pumpkin because in some horticultural show a throw away line occurred - What sort of pumpkin is that? - It's a Jap (= just another pumpkin) stuck even though they are strictly a Kent. I haven't checked that story out.

They don't keep well but they will go into the root cellar in a few days after drying out a bit more. We have three Queensland Blue pumpkins already stored away.

Also picture of a shallot harvested from one of the growbeds, they grow really well in that medium. It is about 1m long.



Raining today - 10mm so far - whilst our tanks are reasonably full, it is welcome for the garden.

Two more edible weeds that are closely related

Binomial name : Plantago lanceolata
Common name : Ribwort Plantain

and Plantago coronopus
Common name : Buck's horn Plantain

We don't have Plantago major on our property

The use of the name Plantain is confusing, as there is a variety of banana also called this. I like to use proper (ie scientific or binomial) names for exactly this reason - there is no doubt what plant I am talking/writing about ,whereas with common names there can be confusion. The common name of plantain is from the latin planta meaning sole (as in shoe) as the leaf shape is vaguely thus shaped, for Plantago major anyway.

Plantago sp (probably lanceolata) is a weed I remember from my childhood in New Zealand - we used to break off the seed stalks with seed head attached, make a loop from the stalk and use this to shoot off the seed head usually towards some other child ! Another game we played was to see how many times we could tear a leaf and still have it hang together ( explanation of this following).

Also in this family is Plantago psyllium, the seeds of which are processed to make the laxative metamucil.

Identification -for P lanceolata:

The rosette is about 400mm wide and 300mm high. Leaves are 200mm long and about40mm wide with 7 readily seen veins. Flowering stems are 500mm high with seed heads about 300mm x10mm thick. Each plant has up to 3 flowering stems/plant. If a leaf is broken into two there are strings evident which tie the two halves together. There is a fibrous root system

For Buck's horn plantain the leaves are somewhat jagged and the plant is overall of similar dimension to the former species. It has a pretty impressive taproot that measured 160mm on the specimen I pulled out. Any breaks in the plant - leaves and root exude a white sap as well.


Plantago (especially P major) has a long and colouful usage by humans. It was found in the stomachs of the bog bodies from the late stone age in Denmark. It was mentioned by the Greek Physician Dioscorides from the first century. The Vikings recorded using it to heal wounds, and the Saxons venerated it as a sacred herb. Shakespeare mentioned it in Romeo and Juliet as a herb to heal.
In Act 1 Scene 2 - he writes:

ROMEO Your plaintain-leaf is excellent for that.
BENVOLIO For what, I pray thee?
ROMEO For your broken shin.

P coronopus was cultivated in Europe and England as a potherb for 300 years.

Young plantain leaves are eaten as a minor potherb in Europe, China and North America and the mucilaginous seeds are used in Asia to make a drink.


Not sure of actual amounts/100gm but the following are listed:
carotenoids, flavonoids, mucilage, calcium, monoterpene alkaloids, glycosides, sugars, triterpenes, linoleic acid, iridoids, and tannins.
Some of these are no real surprise, especially the carotenoids,alkaloids and tannins. Linoleic acid is a type of omega 3 fatty acid.

Pubmed search:

There are lots of studies on Plantago species - here are a few:
1 P. asiatica essential oils decrease total cholesterol by blocking the same enzyme in the liver that Statin drugs ( eg Lipex) act on.
2.A number of Plantago sp especially P major have long been used in the treatment of diseases such as infection ,inflammation and cancer and in this study of 5 types of compounds from Plantago major on human white cells ( lymphocytes) it was found that there was an increase in lymphocyte proliferation and production of gamma interferon. This basically confirms traditional usage, as the result of those two things happening is basically to turn up our immune system.
3 P. asiatica also seems to have a compound in it that acts on the Angiotensin converting enzyme.Blocking this enzyme results in the lowering of blood pressure and this pathway is used in modern medicine by such drugs as Coversyl and Monopril and lots of others.
4. Finally another study showed that Plantago major had significant anti-inflammatory and anti-oxidant effects.

There is also lots more about this weed which is really interesting such as the traditional use for stopping bleeding and for treating wounds. No doubt it has anti-bacterial activity as well, and of course the usage as a laxative.

What part to eat:

Young leaves from young plants - blanch to remove bitterness.

We find P lanceolata too bitter and stringy to bother with. Tim Low in his book also makes the same comment.
P coronopus is more palatable, not stringy at all and has no bitter taste.

However, fascinating pubmed stuff on them generally.


Sunday, August 8, 2010

Miner's lettuce

Here's a weed that I don't have growing on my property, yet, but which we ate when we were in Auckland, over the weekend. It seems as though Gerry Colby Williams has it growing in Wynnum - a nearby suburb - so I must try and get some as it is a nice salad item.

the link to the Gerry Colby Williams article is: http://www.organicgardener.com.au/articles/rounding-volunteers

Binomial name : Montia perfoliata
Common name : Miner's Lettuce


It was called Miner's lettuce as it was eaten during the California Gold Rush days to help prevent scurvy. In the last century it was cultivated in Europe as "winter purslane" and arrived in Australia/New Zealand during the gold rush days via miners from California.

Identification :

It is a small herb with disc shaped leaves on long stems, about 10cm high in my mother's Auckland garden. Tim Low ( Wild Herbs of Australia and New Zealand) records it as occurring in the cooler parts of Australia and in New Zealand. The flower stalks appear to pierce the centre of a rounded leaf. There a tiny white flowers with five petals ( no flowers seen this time though).


The leaves are quite succulent in salads as we had today, and could be lightly boiled like chickweed as a potherb.


20kcal/100gm (about 1 cup full)
Vit C - about 30mg ( the figure quoted is 33% of the RDI which is around 90mg/day)
Vit A -about 600IU ( also only quoted as 22% of the RDI which is about 3000IU)
Iron -10% of the RDI ( varies with age - adult male is 8mg - females about double that)

Medical :

Nothing to report

If you already have this weed growing it really is quite mild and lacking any bitterness and makes a good addition to a salad in my opinion.

Photo from Google images - we didn't take our camera!


My mother also had Hypochoeris radicata growing - the leaf surface was quite hairy compared to the Catsears I have here so my assumption that I had H glaba was probably correct.

Thursday, August 5, 2010

Emilia sonchifolia

Back onto edible weeds.The talk at Springdale Garden Club went well and certainly stimulated some interesting questions.

We had a koala in a small tree at the back of our vegie garden 2 days ago - it is always exciting to see them. This one was quite large, but would not pose well for a photo - therefore it must have been a male!

Here's another edible weed:

binomial name : Emilia sonchifolia
common name : lilac tassel flower, cupid's shaving brush, purple emily

The latin species name of sonchifolia gives a clue as to what the plant looks like - it has sowthistle like leaves.


It is a relatively sparse spreading weed with purplish green leaves like sowthistle. Lower leaves are deeply irregular and toothed with lobes almost round. Upper leaves are hemiamplexicaul (grasp the stem) elongated and coarsely dentate (toothed) The flowers are a lilac color unlike the yellow of dandelion/catsears/sonchus. Overall height is to about 80cm. It is an annual plant that occurs in our garden beds and is present now, I think however, that it is around most of the time in my garden. This photo is the best we could do- there are probably better images than this on Google images


Young leaves are used in rural China in a manner similar to European use of dandelion. Similarly in Java the leaves are eaten with rice, and in Central America in salads. In Indian medicine it has been used to treat fever, asthma and diarrhoea. In Nigeria, an extract is used to treat infantile convulsions.

Nutritional :

Not much information available . Anti-oxidants no doubt and some pretty amazing chemicals yet to be well documented (see medical reports). It does seem to have pyrrolidizine alkaloids.

What part to eat :

Young leaves definitely: Tim Low states that flowering plant leaves are too bitter to bother with. We have tried some steamed leaves, they have a definite carroty flavour. It would be ok in a salad, well diced or a few young leaves mixed with other greens. Don't eat much of this plant or too often.

Medical reports (Pubmed/Scirus):

A leaf extract showed a marked anti-inflammatory effect on the rat paw oedema model Similarly an extract also had a marked anti-convulsant effect (confirms the Nigerian use above) A Methanolic extract also had an anti-tumour effect and was cytotoxic to lymphoma cells but not normal lymphocytes. It also decreased the development of solid and ascitic tumours in rats. Finally, a fresh juice and methanolic extract showed potent anti-oxidant activity.

Conclusion :

Another interesting weed to try. Shame it has pyrrolidizine alkaloids . Only use occasionally and a few leaves at a time.


ps away for 3 days so no posting

ref: Tim Low -Wild Herbs of Australia and New Zealand

Wednesday, August 4, 2010

Mary's art

Here's some pictures by our daughter Mary - the burning church one is quite sobering for some reason.

Also during the week we went and had a look at Nicola Moss' exhibition at the Redlands Art Gallery - what a truly talented artist with a very unique but delightful style. If you get the opportunity go to Cleveland and see it before it closes in a week or so (the 15th I believe)

Back to some edible weeds/garden stuff tomorrow!

Tuesday, August 3, 2010

possible adverse chemicals in edible weeds

Apart from obviously needing to be 100% sure of identification
there are 4 general chemical compounds to be aware of when eating weeds

1 Oxalic Acid:
This occurs in quite a few weeds -however in context, spinach and silverbeet that we eat without regard also contain oxalic acid in quite high amounts. The highest amount of oxalate in a weed is in Fathen - Chenopodium album, then Purslane and then Spinach - the other weeds are less than Spinach. Oxalic acid gives plants an acid taste and it can be removed by boiling for a few minutes and then replacing the water. This also helps remove any bitterness of alkaloids or other chemicals as well.
There are no recorded deaths in Australia from oxalate poisoning - there was one in Canada a long time ago (1913) from someone who ate rhubarb leaves. The LD50 for oxalic acid seems to be 25gm for a 65 kg human - to eat this much of Fathen would require eating 2.5kg in one sitting. To eat such an amount would be unlikely.
Theoretically - too much soluble oxalate in your blood stream would combine with Calcium with the possible consequence of muscle weakness, cardiac rhythm disturbance and when excreted, kidney stones. Interestingly in my practice, Calcium oxalate stones are the most common type but the patients with kidney stones are not the ones eating lots of green leafy vegetables! Also, theoretically, too much oxalate chronically, might contribute to thinning of the bones (osteoporosis) but it may also bind to toxic metals such as mercury and lead allowing them to be excreted and thus be beneficial.
So, on balance, if you eat spinach and silverbeet you are already getting a fair dose of oxalic acid. As a precaution, we tend to blanch the wild greens with elevated levels of this chemical.

2 Alkaloids - especially pyrrolizidine alkaloids.
Alkaloids are ubiqitous -caffeine is an alkaloid, as is nicotine , morphine etc and they are not all bad in small amounts. One class of alkaloids is however harmful and they are called pyrrolizidine alkaloids. These can cause liver damage and cancer when eaten over for a prolonged period. The banning of comfrey was due to it containing certain pyrrolizidine alkaloids and indeed some of weeds have also been reported to have contain similar compounds. The only one that we have tried that contains pyrrolizidine alkaloids is Thickhead - Crassocephalum crepidiodes. I am also suspicious of Cobbler's pegs (Bidens pilosa) having pyrrolizidine alkaloids but have not found any evidence for this on the internet.

Cyanide :
Surprisingly, cyanide occurs in some of our foods -lima beans, chick peas, almonds, bamboo shoots, cassava and apple pips - and also in the leaves of 2 weed species that I am aware of , the leaves of Black Nightshade and Stinking Passionfruit. It is readily destroyed by cooking so is not really an issue . Humans can cope with very small doses of cyanide with it being excreted through the lungs anyway.

Nitrates and Nitrites:
A large number of weeds are nitrate concentrators - fathen, amaranth, sonchus - as is spinach, silverbeet, lettuce and broccoli. Nitrates are ok anyway - lethal dose is 8-15gm for an adult male, but nitrate can convert to nitrite in certain conditions and this is lethal at about 1gm for an adult male. To eat such an amount would require eating prodigous quantities of overfertilised, wilted, insect chewed leaves, and this would apply to any other leafy vegetable anyway

So risks - oxalic acid and pyrrolizidine alkaloids worth remembering -but from my viewpoint the amounts we might eat in a salad or as a boiled vegetable would be way to little for this to be a real concern.

Obviously avoid eating weeds that may have been sprayed - eg roadsides/reserves and weeds that are growing on contaminated sites as many are heavy metal accumulators.

As a general rule - pick and eat the very youngest leaves as these will have less of any bad chemicals in them and taste better!


Sunday, August 1, 2010

New Guinea bean

I've been busy preparing for another garden club edible weeds talk on Wednesday.It will be the same talk I gave recently but still it needs some preparation. Weeds for the talk are Purslane, Sowthistle, Gotu Kola, Dock, Chickweed and Warrigal Greens.

Meanwhile here are 3 photos:

The first is of a dried New Guinea bean (Lagenaria siceraria) that we grew for the first time this summer.As it dried it has developed amazing patterns from fungal growths on the shell of the gourd. It was quite nice eating as well and was quite prolific, growing readily and relatively pest free. The other beans we harvested were straight and up to 1m long and as thick as a forearm.

I'm going to spray varnish it to keep it as an item of interest - it looks a bit like a snake!

The next photos is of a Camellia flower- we have 3 bushes of Camellias outside the study - they are tough, although they do have a bug a present that is damaging some leaves.

Finally our Brassicas are growing apace - here's a cauliflower almost ready for harvesting- they have done brillantly the past 2-3 months in the cooler weather