Real World Gardener Blossom End Rot in Plant Doctor

February 7th, 2015

  REAL WORLD GARDENER Wed. 5pm 2RRR 88.5fm Sydney, streaming live at and Across Australia on the Community Radio Network.<?xml:namespace prefix = "o" />


Real World Gardener is funded by the Community Broadcasting Foundation (CBF).

The complete CRN edition of RWG is available on , just click on 2RRR to find this week’s edition. The new theme is sung by Harry Hughes from his album Songs of the Garden. You can hear samples of the album from the website


with Steve Falcioni from


Deficiencies in plants are hard to diagnose especially if it’s in the leaf.

Sometimes though they stick out like a sore thumb, particularly on some veggies like tomatoes.

Other times with other vegetables, it’s a bit confusing because it could fungal, or you didn’t fertilise or water enough.

The problem will show up when the fruit is about half-size or half ripe with zucchinis.


With tomatoes, they'll still be green when you start to see the blackness on the bottom end of the tomato.

Too much or too little water can mean the plant can't take up calcium, even more so if you've used artificial fertilisers.

The artificial fertilisers include those powders that you mix with water. These sodium and nitrate ions which mean the plant prioritises take up other nutrients at the expense of calcium.

proxy?url=http%3A%2F%2F2.bp.blogspot.comLack of calcium is most likely the cause if the problem shows up when the fruit is bigger-almost half ripened.

Calcium deficiency is treatable but it won’t reverse the problem you’re seeing on your vegetables right now.

So those veggies that have got it now-you’re stuck with.

I have read about crushing egg shells and mixing them into the soil to correct calcium deficiency, but that takes months and months before the calcium is available to the plants. Just not worth it.

If you apply gypsum in a liquid form, it gets absorbed quicker and may just fix the problem on your zucchinis on tomatoes in as little as a couple of weeks.

Gypsum is calcium plus sulphur, which doesn't change soil pH.

Otherwise, applying the powder form of gypsum takes at least a season to work it’ way into the soil.

If you have any questions about blossom end rot or a photo of a sad veggie you want diagnosed, send it in to or write in to 2RRR P.O. Box 644 Gladesville NSW 1675.

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