How to avoid blossum end rot in coco?

Had major issues with BER on my outdoor tomatoes last season. Growing in 5gal buckets of coco, Hempy style. Was using Maxibloom at 1tsp per gallon with between 5-10ml of a C/M additive, pH'ed to around 5.6-5.8. Plants were probably 10 ft tall or so, to the point that I needed a step stool to tend to the tops. Even with the C/M+ added I probably threw away 60-70% of my fruits due to BER!

Making me consider trying a different medium this year, maybe that Sure to Grow fiber stuff? With our semihard water, and the cal/mag issues associated with using coco, its definately something I'm considering.

Any other medium ideas?

Or maybe try that tomato specific nutrient from GH? (forgot the name)

could be uneven watering as much or more than camg. If they wilt due to dry soil as opposed to ambient heat then thats probably the case. Once they root into the coco its more or less hydro. Game on water water water. I often water indoor plants in 3gal pots 3 times a day. They eat it up.

tomatoes are defiantly calcium whores. with that size plant i would just up the calcium. no need to switch mediums.

I second the uneven watering. That is more often to culprit more so than lack of Ca. Put 'em on a timer and make sure that the area around the base of the plant is being evenly watered. I like using a ring of emitters for this purpose.

sorry for the late reply, but what was the RH when you lost the crop??

take care

Edit: By RH i mean the humidity..

Uneven watering is usually the culprit with ber in tomatoes. It affects how the calcium is taken in.

uneven watering? don't you mean too high a RH??

No, I'm positive they meant what they said--uneven WATERING, not relative humidity.

KosmoKramer said:

Had major issues with BER on my outdoor tomatoes last season. Growing in 5gal buckets of coco, Hempy style. Was using Maxibloom at 1tsp per gallon with between 5-10ml of a C/M additive, pH'ed to around 5.6-5.8. Plants were probably 10 ft tall or so, to the point that I needed a step stool to tend to the tops. Even with the C/M+ added I probably threw away 60-70% of my fruits due to BER!

Making me consider trying a different medium this year, maybe that Sure to Grow fiber stuff? With our semihard water, and the cal/mag issues associated with using coco, its definately something I'm considering.

Any other medium ideas?

Or maybe try that tomato specific nutrient from GH? (forgot the name)

Click to expand...

Ugh.. hydro nutrients for a good old-fashioned tomato?

Blossom end rot is specifically a Ca-, not a Ca/Mg-. And in my opinion you'll have far fewer problems if you use soil food web techniques, especially with regard to utilization of available nutrients.

However, I've only grown WEED in coir, I would think it's insanely expensive to grow tomatoes in coir. I do grow tomatoes--outdoors, in good soil using soil food web techniques.

IMO, you should try using some urine, instead. Yes, I'm serious.

I've also been told uneven watering, however, in my situation I've found that evening out watering does nothing to alleviate the BER I see not just in my tomatoes, but in my peppers and eggplants, where addition of a Ca amendment to the soil tends to alleviate the problem, immediately.

BER is not usually caused by a lack of Ca in the soil (it can be though). Usually, it is an inability to use the calcium that is in the soil.

As calcium is not a "mobile element" like K or Mg, it relies on transpiration for transport, so the advice on constant soil moisture is good advice.

Other problems/notes on Ca uptake/use by the plant:

Too much N during fruit formation interferes with calcium uptake, causing BER.

pH of 6.5-6.7 is ideal for calcium uptake.

Too much K during fruit formation interferes with calcium uptake.

When growing in containers, make sure the buckets do not get too hot in the sun. A black bucket can heat the rootball excessively and is a surefire way to induce BER.

Some folks like to use a foliar Ca spray like FoliCal (calcium acetate) to bypass the normal chain of transport and supply calcium right where it is needed (on the fruit). There is debate as to whether this is effective. I think controlling the variables I mentioned above is the best way to consistently avoid BER.

What I meant with the high humidity is that the blossom end rot often comes when there is high humidity.
That causes the evaporation from the leaves to slow down/stop which in turn stops Ca from being pulled up from the soil..

I got a fair amount of blossom end rot in my tomatoes last summer in my vegetable garden. It was hot and humid, and I planted too many plants close together. I'm thinking of buying some of this to see if it helps fix the problem this coming summer:

http://www.4hydroponics.com/nutrients/items.asp?ItemNo=tomatovegetable

-Funk

As I've said, it might not be the ferts that is wrong. If the air is very humid, is because of low water-uptakes from the plants, that give the ber..

I'm in the Sierra Nevada mountains, and the RH can get a bit on the low side. Not (usually) desert low, but it could hardly be considered high. We've been considering covering one area of raised beds with a greenhouse, which would automatically raise RH. I find myself wondering if a raised RH would allow even better evenness of watering.

I've been assuming that because the beds have been placed over a large sand filter that the water has been running right through them and washing whatever Ca is in the soil out. Sinkyone suggested a couple of years ago that I try evening out the watering around the plants and that could reduce both cracking of fruits as well as the BER issue, and it did not help in any noticeable manner. I add Ca in whatever form (Cal-Phos, oyster shell, dolomite lime) and the BER alleviates significantly, may even disappear. This last summer it was the worst, and we had to significantly reduce the amount of water given the gardens because last year was the year with no summer. I got exactly ONE MONTH of tomatoes, and that was IT--September 1 I got the first ripe fruits, and by October 1 we were done.


Does that mean that my conclusions based on these observations are still off, or what? I'd like to get the answer for my particular problem nailed down because I'm fairly certain it's going to happen again this year. Especially with me being so weak after a knee surgery. Just going down to the garden itself and gathering a few spring onions and a couple of carrots, and weeding an incredibly small area left me completely sore and wiped OUT, I need to plan ahead on amendments and bed preparation.

Hi SeaMaiden

You need to have your soil tested.

Ca is indeed one of the nutrients that can be leached down out of reach of the roots.

On the other hand, if you added oyster shell or dolomitic lime in the last 3 years, that should have taken care of it.

The problem with just adding more shell or dolomite are the problems that can occur with too much Ca or Mg. Too much Ca can make K and P, and most of the micronutrients unavailable. Too much Mg can cause big problems too. What makes it worse is that once you have added too much oyster shell or lime it takes a long time (years) to correct.

Here is a link to Kinsey's Agricultural Services, they specialize in testing and correcting soil infertility, they do a much better job than the testing you can get from the local university's Ag extension office. I don't know what they charge, but Kinsey is the man when it comes to fixing problems like yours. I believe you can send a sample for testing and recommendations to Kinsey himself, but he also has a number of associates throughout the US, many of them in California. Look at the list of consultants on the website, maybe one of them is right around the corner from you. All these guys cater to the big farms and orchards, vineyards etc. , but I bet they would help you out.