Wednesday, December 30, 2009

Is It a Wedding?

Well, they're veiled in white...
And blushing...

Unfortunately, the only romantic thing is that these are my tomatoes, and they're starting to ripen!

Those white 'veils' are fruit-fly exclusion bags. I thought I saw a fruit-fly and acted about a week before Christmas to cover the fruit.

Queensland Fruit Fly is a serious pest for both commercial fruit growers and home gardeners. In Sydney, the fly is active after Christmas -- it likes the warm, humid conditions. It lays its eggs in a whole range of garden fruits, but particularly likes stone fruit, and tomatoes and capsicums. QFF doesn't attack cucurbits, but a bad infestation will see them in almost everything else. Home gardeners normally see them in tomatoes, though cherry tomatoes are rarely affected.

I should mention that the tiny flies commonly seen hovering over those grapes you forgot to eat, or in the less reputable fruit shops, are vinegar flies (Drosophila), not Queensland Fruit Fly.

The fly usually lays its eggs near the calyx, making the 'sting mark' less obvious (though in a bad infestation you will see sting marks everywhere!). Its maggots then eat the fruit from the inside. When they're ready to pupate, they will have eaten enough of the fruit's insides for it to fall to the ground. The maggots burrow into the soil to pupate before hatching out as adult flies (a bit smaller than a house-fly). In ideal conditions it takes about a month for a fly to go from egg to sexual maturity, and they lay eggs for weeks afterwards...

Thus everyone who has grown up with home-grown tomatoes here has also grown up with the sight and stench of rotting tomatoes, and the sound of cranky gardeners calling down curses upon Bactrocera tryoni.

How do we control it? Well, the most important thing is to practice good hygiene. Firstly, fruit trees should be looked after so they do not shelter fruit flies (there is a legal requirement that I strip my quince tree of fruit at the end of April to prevent fruit fly over-wintering in them). Make sure the tree is not too tall to check the fruit. Fallen or infected fruit should be either solarised or frozen. My Dad's preferred method was to add the fruit to his 44-gallon drum of compost tea!

To be truthful, the best control of fruit fly is through regular spraying of systemic insecticide. I'm a busy person with children, and I like the other minibeasts in my garden, so there are a host of reasons I don't want to spray. My contacts with other gardeners have led me to believe that baits and lures are not terribly effective, so I am going with barriers instead.

We have had dry summers for the last few years, which have reduced the numbers of QFF in Sydney. I am concerned that this year, as vegetable gardening has been booming in popularity, and there are many novice tomato growers around, we will see QFF in plague proportions.

Your Department of Agriculture or Primary Industries will have a fact sheet about Queensland Fruit Fly for your area. Please read it and follow its directions. Be especially careful to follow the local regulations if you are travelling into a fruit fly exclusion zone this summer.

Monday, December 28, 2009

Is it Obsessive...?

We had a bit of light rain on Christmas Day, enough to dampen the ground. But with a few days of rain and cool weather forecast, it was obviously the right time to plant my advanced vegetable seedlings. So there I was on Boxing Day morning, rain on my back, hurrying to get my plants into the ground. Pumpkin 'Potimarron' under the quince tree, then a few heirloom tomatoes, capsicums, shallots and lettuces into the main garden. I think I only reached 'obsessive gardener' status when the rain started to run off the tip of my nose.

What do you think?

Friday, December 25, 2009

Merry Christmas

I've just discovered this carol, and it's botanical, so here it is.

And Mary bore Jesus Christ our Saviour for to be,
And the first tree in the greenwood, it was the holly.
With best wishes to my friends in the blogosphere,


Saturday, December 19, 2009


I see it has been a month since I last posted. Not quite what I had planned!

Here is what's happened in that time:

  • I cured Lizzie of broodiness.
  • The iron deficiency on the tomato plant was resolved with some seaweed tea, as mentioned earlier.
  • Some of my tomatoes were holed by tomato worm.
  • My children suffered from a nasty vomiting bug.
  • My husband caught an evil summer cold and passed it on to me.
  • Australian politics has been quite entertaining.
  • We uncovered the evil lurking on the Internet. The boys keep singing Queen songs, despite the fact that neither of their parents particularly like Queen. It's all happened because the Twig likes watching domino videos, though why these always involve Queen tunes is unfathomable. I shall be writing to Stephen Conroy about this!
  • I had mysteriously bad germination of sweet corn and of beans.
  • The lemon cucumber and bean plants (the ones that came up) are in full production.
  • The chillies on the chilli plant look like small, half-deflated green balloons, and are quite hot.
  • There are borers in some of my older wattle trees. I will wait until autumn to cut them down.
  • I'm really hoping those yellow leaves on the 'Brandywine' tomatoes are caused by sunburn from our 40 degree day earlier this week.
  • I turned 40.
  • We've been preparing for Christmas!