Sunday, August 7, 2011

Blossom End Rot

Blossom End Rot - it’s ugly and disheartening.  After providing much tender loving care, to see these nasty black spots on our tomatoes is heart wrenching, as you read in Leanne’s post.
So, let’s get down to it – what is it and what can we do about it.
tomatoes with BER, peppers with scarred areas chewed by squirrel

Happy, stress free tomatoes

Blossom End Rot (BER) – What Is It?
It starts with a water-soaked area on the flower end of the tomato (the bottom).  That “stained” area turns brown and then eventually into a dark, black area.  It may be the size of a quarter or it may cover the entire bottom of a tomato.  Then, if it is attacked by other organisms, it may get soft, mushy and completely rotten.  (Hey, I told you it was ugly!)  Assuming it hasn’t gotten to this last stage and the affected area is relatively small, you can cut the black area out and still eat the tomato.  Because it’s a physiological condition, it does not spread from one tomato to the other, but you may want to remove the spoiled fruit to avoid other pests from moving in.

Blossom End Rot – What Causes It?
A lack of calcium being absorbed by the plant is apparently the cause.  It’s not necessarily that there’s a lack of calcium in the soil (although that may be the case in some rare situations), it’s often that the plant isn’t absorbing it (that’s why simply adding calcium to the soil upon the first sign of BER doesn’t work).

Stress caused by weather and water conditions greatly impacts the plant.  For plants, stress may mean inconsistent weather and watering conditions – too hot, too dry, too cold, too wet and everything in between in one growing season.  The transition from a cool, wet spring to a hot, dry summer may also cause some initial stress to the plants, which is why it is often the first few tomatoes on the vine that seem to get it the worst.

Another stress factor is disturbing the roots.  Be careful about hoeing or weeding around your tomato plants as the roots may be injured. 

Blossom End Rot – What to Do About It?
Soil – Think about your soil for a moment.  Key considerations for me are sufficient drainage and organic matter. When was the last time you added any compost to your soil? Is your soil able to hold some moisture without causing roots to be too wet for too long?   If everything in your garden is growing well and has lush, green foliage your soil is probably just fine.    However, if you have other concerns you might choose to get a soil test done at a local garden centre to help fine tune your garden soil. 
Having adequate soil is a year- long/life-long process.  Simply tossing some lime or crushed egg shells around your fully grown tomato plants in the hopes of increasing the calcium levels is not likely to do anything.  However, planning for next year’s crop by adding compost or well cured manure in the fall or spring may indeed prove successful.  Or, digging deep holes for planting  your tomatoes and adding crushed eggshells and compost to the bottom of the hole, like my gardening neighbour Ed does every year, may also bring more success.
Watering – Be consistent with your watering.  A nice even amount of water should do the trick.  I know this is an issue for us.    I just can’t bring myself to “consistently” transport jugs of water down to the garden – so I’m being consistent by not watering.
Mulch – A good 3 inch layer of mulch around your tomatoes will hold in the moisture around your plants.  We did this last year and I could definitely tell the difference between the mulched areas and those that didn’t have any mulch.  But, this year, we didn’t have the mulch material and we ran out of time, so our plants just have to fend for themselves.

There you have it, more info on the yucky black spots on your tomatoes than you probably wanted to know.  The good news is that it’s not contagious (to you or to other tomatoes) and that probably not all of your tomatoes will get it.  The bad news is, there’s very little you can do about it. 

Provide a consistent, stress free environment and hope for the best.  Who wouldn't thrive in those kind of conditions!

Other resources on BER you might want to consult:

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