Saturday, 17 March 2018

Powder Puffs, Historic Gardens and Beautiful Hedges

What’s On The Show Today?

We’re visiting a historic garden in Garden History segment, why do my beans taste bad in Vegetable Heroes, Useful & Beautiful hedges in Design Elements and flowers without petals in Plant of the week.


Camden Park Estate
Have you ever wondered how gardens became established during colonial times?
You might be surprised that there were even catalogs of plants that grew in many large colonial gardens.
It’s a real treasure and rare to discover that a historical garden complete with dwelling is still around, but to find such a place that has remained with the same family is even rarer.
When you hear that growing in the garden is one of Australia’s trees, then you have an enticing combination.
Camden Park Estate Pic: Creative Commons
This estate is so interwoven into Australia’s Colonial history, that it would be unthinkable that it would be developed into blocks of apartments.
Let’s find out how this garden estate continues.
I'm talking with Stuart Read, committee member of the Garden History Society of Australia.

Stuart mentioned that you can view the old plant nursery catalogues online.
The website is
The Hortus (which is a collection) attempts to correctly identify, describe, illustrate and provide a brief history of all the plants grown at Camden Park between c.1820 and 1861.
You can also just look up when a certain plant came into cultivation in Australia.
For example the Hoop Pine entry in the Hortus reads
Hoop Pine Araucaria cunnimghamiana
Pic: Tatters @ Flickr

“‘Grows naturally in warm temperate riverine and costal rainforest or as a pioneer in subtropical forest, on poor soils from the Macleay River in N New South Wales to Townsville and offshore islands including New Guinea, occasionally close to the seashore. Widely grown in the nineteenth century in public parks and gardens; now rarely planted in SE Australia. […] The timber, grown in rainforest plantations in N New South Wales and S Queensland, is used mostly for plywood, but also for joinery, furniture and boat-building. More recently this species has been used experimentally for agroforestry.’”

If you have any questions either for me or for Stuart, you can email us or write in to 2rrr, PO Box 644 Gladesville NSW 1675.


VEGETABLE HERO has a problem.

So, you’re looking at your spinach and you see holes in the leaves, but they’re all uniform and perfectly formed, right?

What insect does that?
Or, are the stems or your Silverbeet have an ugly blackish brown stain down the middle of them?

Perhaps the leaves have got that rusty look, and definitely look some-one had a go with a blow torch?

Wait, have your cucumber leaves gone all white and crispy, then start turning brown and collapse in a heap in the veggie bed?

You probably have read or heard the advice that the most important things you can do to prevent fungal problems is to avoid overwatering, overhead watering and excessive fertilizing and keep your garden free of debris.

O.K. what about some of us that had all that rain?
Powdery mildew on Okra
Or you might’ve heard that you need to mulch well and avoid watering the leaves or splashing soil borne particles on the leaves.
One things for sure, you can water or fertilise away the problem.

Firstly what is this fungus thing anyway?

What causes fungal diseases?

  • Fungus are structures which produce spores. 
  • Disease‑causing fungi penetrate the plant for food during their growth stage, then produce spores which can, in turn, produce new fungus. 
  • The fungus feeds of your plants because not containing chlorophyll, it can’t make its own food. 
Did you know that there are two main types of spores ?
  • Short-lived spores which quickly produce new fungus to grow and spread through plants while there is plenty of food. 
  • These spores allow a fungal disease to spread very quickly during the growing season. 
  • Then there’s the Long-lived spores which are very hardy and allow a disease to carry over during periods of stress, for example when there is no food. 

So what does fungus love?

Which fungus shall I start with?

How about powdery mildew?
A fungal disease around a lot in spring and autumn when days are warm and nights are cool.
Powdery mildew is a white or grayish powdery/mouldy growth that you see on the leaves and new shoots.
Powdery Mildew on Cucumber Leaves: notice white powder covering the leaves and then the decayed leaves.
The leaves look deformed, and will always start to collapse, particularly on the cucurbit family, like Pumpkins, zucchini and cucumbers.
The leaves are never going to return to a normal appearance, so getting rid of them will help to stop the spreading of fungal spores.
Yes, that includes the ones that have fallen into a crumbled mess in the veggie bed.
Cercospora leaf spot on Swiss Chard: photo Scot Nelson Flickr

Fungal Leaf Spot

The next fungal problem I’m going to mention appeared on my spinach this year. That is Fungal leaf spot.

There are many types of leaf spot diseases that can affect beetroot, broad beans, carrots celery, peas, potatoes (early blight) silverbeet and tomatoes (targetspot).

Sometimes the leaf spots cause only slight damage, but other times they practically destroy the leaves of the plant in question.

How do I fix this?
  • Basically, if you’ve already got it, you can’t because as I mentioned, the leaves won’t return to normal, but you can stop the spread to other new leaves and other plants in the garden. 
  • All of these above symptoms signal fungal problems in the garden, a lot of which can be fixed with physical things like improving air circulation around the plants. 
  • You can also dig the problem leaves into the soil since sexual spores of the fungus won’t develop on buried leaves. 
  • In all cases, fungal problems can be treated organically 
  • You can try spraying with a good compost tea, or seaweed extract. 
  • Or secondly, try spraying with bi-carbonate of soda (sodium bicarbonate) because it will also kill powdery mildew. 

RECIPE:To make mix 1 tablespoon of baking soda, 2 ½ tablespoons of vegetable oil with 4 litres of water.

TIP: The sodium in the baking soda will combine with chlorine in your water supply to form table salt (sodium chloride).

A better choice is  eco carb which contains potassium bicarbonate where the potassium becomes a plant nutrient. 



Useful and Beautiful Hedges

The “useful and beautiful” series is up to hedges.
You’re probably thinking that we’re going to be talking about Murraya paniculata, or just Murray or the colder growing version, Choisya ternata.
Perhaps you even thought we would talk Buxus or Lilly Pilly?
But no, we’ve chosen something completely different, after all, it has to be useful and beautiful.
Let’s find out what they are.
Choisya ternata, Mexican Orange Blossom
I'm talking with Peter Nixon Director of
PLAY: Useful & Beautiful Bulbs_28th February 2018
Peter mentioned shrub roses like Miss Lowes Rose, Bengal Crimson and Rosa sanguinea.
For more scent choose Rosa chinensis 1,000 lights.
Rosa sanguinea photo: T. Kiya from Japan
If you have any questions about hedges , either for me or for Peter or have some information to share, why not drop us a line to or write in to 2RRR PO Box 644 Gladesville NSW 1675 


 Calliandra heamatocephala 
If someone told you that the flowers on a particular tree were like a powder puff, you wouldn’t be wrong in thinking that it was from a lily pilly.
Lily Pillies don’t hold the whole ball of wax on staminous flowers.
In fact if you think about it, gum trees have staminous flowers: that is, flowers that are made up of stamens but no petals.
Calliandra tweedii, Pom Pom bush
Today though, it’s another family that has this trait and it’s one to look out for.
Let’s find more.
I'm talking with Karen Smith of

Calliandra tweedii is also known as the Mexican Flame bush because of its fiery red flowers. 
Calliandra tweedii: Mixican Flame Bush photo: Magnus Manske

This is a much lower growing sub-shrub, to a height of 60cm x 1.2m
This variety of Calliandra has fern like foliage like all of the other Calliandra varieties.
The leaves are evergreen except in districts that experience a hard frost.
The leaves will then drop off, but the shrub will recover in Spring.
Like all Calliandras, in warmer areas the shrub will spot flower during all the warmer months.

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