Permaculture in Action

Wednesday, January 22, 2014

Gardening Tips

Blossom end rot in tomatoes looks like this...

 It appears on the blossom end of the fruit as it develops, causing major blemish and rendering the crop next to useless for marketing. We have experienced the rot on younger garden beds before compost and organic matter move the soil to balance. The cause is primarily due to the lack of calcium in the soil or may be due to stress from drought or water logging.

A key for us is the addition of ground eggshells in the compost. We save all of our egg shells and dry them for crushing and processing in a mortar and pestle. This last job often falls to wwoofers and interns on rainy days when the activities in the garden are restricted.

Another method is to add dolomite or garden or agricultural lime to the soil at the time of bed preparation. Mostly good compost at this time should be enough but young gardens may need a boost.

We have found that the appearance of blossom end rot may be rectified by dusting the plants with dolomite, just as a foliar feed of calcium. Be sure to cast handfuls of the dust from up wind and ensure you do not breath it in. The drift of the application will cover the plant with an added benefit in deterring fungal problems by altering the pH of the leaf surface.

Affected fruits are fed to the chickens


  1. Thanks for the tips Kate. I have had blossom end rot on some of my tomatoes as well as some zucchini.

  2. Since doing your composting workshop we have saved pretty much every single egg shell since :) drying them on the window sill and then moving them to paper bags as you suggested, when we moved 7 months ago I couldn't believe how many we had, I crushed them down and only just fit them into a 5ltr glass jar!!!
    I find it quite therapeutic to sit with the mortar and pestle and grind them down further, I must be quite convincing in my happy state of mind whilst partaking in this chore as I have the children convinced that it is a special privilege to sit and grind away too :)

  3. Thank you! Also check this great DIY organic gardening

    1. Thanks for that flame. The post without content is a bit spammy for my liking and I ask where in the system the calcium comes from when the plant nutrients are fish poo. regards Mark.

  4. Good to know, our Romas are fruiting big time and thankfully, we don't have to deal with this issue.
    Must start saving eggs shells and crushing them, although they do end up in the compost anyway.

    Claire :)

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