Saturday, 15 June 2019

Tropical Planting Without Crying Over Onions

Old Fashioned plants that suit wet tropics and possibly elsewhere starts off the show, in Design Elements; grow nature’s antibiotic in Vegetable Heroes plus an old-fashioned plant re-made in Plant of the Week, plus, sharpening your secateurs just in time for pruning in Tool Time.


Old Fashioned Plants for the Wet Tropics

What is wet tropics? Is it your zone?
High humidity, but not too much over 35 degrees C perhaps? 
In Australia, we would say that Cairns, Babinda, 'cyclone alley' but not the Atherton tablelands, would fit the bill.
Darwin also, although, the Summer's are much hotter.
So what are the plants that would love that?
Let’s find out
I'm talking with Peter Nixon, garden designer and project manager of Paradisus garden design

Peter mentioned: 
Pisonia umbeliffera-bird lime tree.
Mussaenda philippica or M. erythrophylla-showy bracts-large shrub with pink or white bracts.
Warszewiczia coccinea-Pride of Trinidad-bract type red flower.2m sprawly shrub.
Plumeria spp-P obtusa, P.rubra, P. caracasana, P. pudica- but not hybrids like P acuminata who get rust in this zone.
Plumeria rubra photo M Cannon

Perennials, and sub-shrubs:
Pseuderanthemum laxiflorum-purple Prince, open habit, 1m, purple flowers all year.
Heliconia rostrata-red and yellow
Dichorisandra thyrsiflora-Blue ginger.
Persian Shield
Rhinacanthus nasutus,, commonly known as snake jasmine, white butterfly flowers.-Low groundcover
ForShade: try these
Crossandra spp. Firecracker Flower-apricot flower, 400m
Crossandra infundibuliformis- Firecracker flower, (another form)
Strobilanthes dyerianus-Persian shield
Xanthostemon youngii
-red penda, brushlike

If you have any questions either for me or for Peter, drop us a line to or write in to 2RRR PO Box 644 Gladesville  


Onions.  Or allium cepa are from the Alliaceae family that also contains Garlic, Leeks Shallots and Chives.
Most of these have corms or bulbs or underground stems with long thin leaves and clusters of varying numbers of flowers. (Encyclopaedia Britannica)
Did you know that onions were grown as a crop and eaten since prehistoric times?,
Onions are even mentioned in first dynasty of ancient Egypt, circa 3200 BCE, and have appeared in tomb paintings, inscriptions and documents from that time on. Some paintings depict onions heaped onto a banquet table.
  • Did you know that onions were was used to heal gun shot wounds and during World War 1, sphagnum moss was soaked in the juice as a wound dressing?
When to grow Onions?
In sub-tropical, cool temperate, warm temperate and arid climates you can plant them from April until August.

  • Onions are sensitive to the day length for formation of flowers, so it’s important to select the right variety (early – mid-season – late).
  • These varieties have different requirements in the length of daylight hours.
  • Early varieties are short day length onions, mid-season varieties are medium day length onions, and late varieties are long day length onions.
  • If planted out of season, onions may bolt to seed prematurely.
  • For example in temperate climates mid-season onions are sown in winter, growing through spring and harvested in summer.
  • These include Sweet Red and Brown Spanish Onions.
  • They love sunny well drained beds, especially when the bulbs mature in summer.

So why Grow Onions?
Onions are a good companion plant.
Grown around the garden they repel pests.
They contain sulphur which is a strong disinfectant.
How to Grow Onions with Success.
Remember to always lime your soil well a week or two before planting onions.
They love a sweet or alkaline soil.
I don’t really know why alkaline soils are called sweet.
Don't forget avoid applying manures and blood and bone to the beds in which you're about to grow your onions because they prefer alkaline soil.
You can use spent mushroom compost instead of cow manure.
Sowing seeds with Success

  • Onion seeds can be sown into seed raising mix into punnets.
  • Or if you want to sow them directly into the garden, make it easy for yourself, mix the seed with some river sand-say one packet of seed to one cup of sand and sow it that way. Bit like sowing carrots!
  • They can be transplanted to garden beds when the seedlings are around 8 cms tall.
  • According to the “Vegetable Patch” website, there is a secret to planting onion seedlings.
  • Instead of planting them sticking straight up, lay them down in a trench and move the soil back over their roots.
  • In about 10 days they're standing up and growing along strongly.
Some tips to keep your onions growing strongly is
Hand weed around onions to avoid disturbing their roots and bulbs.
 Keep away from nitrogen based liquid fertilisers when your onions are maturing, because the fertiliser will go into their leaves instead of their bulb.
Regularly water your onions.
Lack of water can delay growth or split the bulb.
Because of their strong taste pests generally leave onions alone.
When Do you Pick Your Onions?
  • Harvest onions (except spring onions) when the tops yellow and start drying.
  • This usually takes 6 months, so if you plant seedlings today, yours will be ready  in December.
  • Add a couple of weeks if your using seeds.
  • Pull the whole plant from the ground and leave it to dry in the sun.
  • Turn it every few days and avoid getting them wet (eg dew or rain).
  • Hang them in a cool dry place for around 3 weeks to cure.
  • If you store them in a cool dry place they should keep for a year.
  • This explains why you can buy onions all year round.
  • Eat the bulbs without a good dry skin first .
Why do we cry when we cut onions?
Onions contain complex sulphur compounds.
When you cut into an onion, two chemical reactions take place.
First, when a knife cuts through the cells of an onion, its enzymes release a strong odour.
Second, the onion releases allicin, a volatile sulphur gas that irritates the eyes and sends one rushing for a tissue.
Keeping Onions in the fridge can help with this problem.
To avoid a bitter flavour never, never buy onions that have begun to sprout greens from their stem portion.
This means they’re more than a year old.
If you see sprouts forming in your onions stored at home, simply snip them off and use the green part like chives, put the rest in the compost.
Why Are They Good For You?
Some health studies have shown raw onions to be effective in lowering overall cholesterol while raising HDLs, the good cholesterol.
Additionally, onions kill infectious bacteria, help to control blood sugar, aid in dissolving blood clots, and help to prevent cancer.
Perhaps we could do with eating some French Onion soup. Bon Appetit!


Nandina domestica spp.

  • Best known for it’s hardiness and loved by local councils who seem to plant it willy-nilly, this next plant has morphed into somewhat finer forms.
  • Which is a good thing because it’s one
  • of those old fashioned plants that gardeners would screw up their noses at.
  • Perhaps we can change your mind?

Let’s find out.
I'm talking with Jeremy Critchley owner of out.

Jeremy mentioned Nandina filamentosa with superfine leaves. Use it as a filler plant.
N. citylights-dwarf-60cm also.
N Lemlim-new foliage is green instead of red.


Sharpen Those Secateurs
What’s the state of your gardening secateurs?
Do they open easily, are the blades sharp? You know they’re sharp if they make a clean cut through a plant’s stem without leaving a little tear behind.
Almost as if you only cut through part of the stem and then pulled off the remaining part.
Secateurs and garden snips photo M Cannon
If they’re not sharp, those cuts that you make on your plants will end up with bruising and tearing on the stems leading to dieback and fungal disease problems.
Let’s find out some tips about sharpening those precious garden tools.
I'm talking with Tony Mattson, General Manager of
  • Clean your tools at the end of the day, even if it's just a wipe over with a rag or cloth.
  • What you should be doing is give them a wash with warm water and two teaspoons of dish soap to scrub away sap and dirt from the  blades with a stiff brush
  • This is to prevent that gunk build up on the blades which can harbour disease.
  • Rub some vegetable oil onto the blades before putting them away to prevent the blades from rusting.

To quote a long time gardening presenter on Gippsland FM Community radio, 
"The jobs not done until the tools are put away."


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