Question
QUESTION: Dear Dr Stephen Vann,

I hope you can help I'm having lots of problems this year with plants in my green house dying, all these are being grown in raised beds in the greenhouse, it starts on the leaves and over a few days spreads and then kills the plants please see photos http://www.knet.co.uk/plants.htm, the plants it is affecting are, Radish, Pak Choi, Nasturtium, Cabbage, Black Current, Spicy Slade Mix, also some young Black Current plants & Tomato plants but these last two I not sure if it is the same problem.

I have many other plants in the green house that look okay, such as lettuce, celery, beetroot, onion, chard. I have checked that they are not over or under watered, and all the plants are on a 3 year bed rotation, I have added grow more to the beds once the plants are large enough.

What did seem strange is the lettuce, land cress, spring onions, beetroot, celery, growing right next door to the Radish, Pak Choi, Nasturtium, Cabbage, Black Current, Spicy Slade Mix and they seem perfectly okay.

The problem is now got worse as all the problem plants are now dying, they come through okay and then start to die within a few days, I have made sevral sowings ad it happens to all the problm plants both in the propogator moduals and sown direct.

If more photos would help I can do this?
I do hope you can help

Ken
Hope you can help

Kind regards
Ken

ANSWER: Ken:
There are a lot of possibilities here. Best if someone could visit your GH in person to size up the situation. Here are some preliminary thoughts. (1) I don't think there is an infectious disease (fungus, bacteria etc.)that is affecting all of these unrelated plants. I think it is something in their growing environment. It is best to try to rule out a few things that could be the problem.  Ask yourself a few questions---
1. Have I used any weed killer chemicals (herbicides) inside the greenhouse or in the immediate vicinity of the building at anytime before or during the time plants were started? Does the building have fans that could bring in any chemicals that might have been sprayed outside?
2. Heating methods- Is the heater a wood or natural/propane gas or electrical? If wood or natural/propane gas - is it vented correctly to the outside? (this exhaust can cause injury!).
3. Location of dying plants. Are they scattered all through the GH or are they all together along one side , near a window/fan, at one end of the house etc?
4. Anything different about the soil I am using? Has there been anything added to the soil? Is the soil a commercial blend or natural from a compost area etc.? Did I use this last season w/no problems?

These are a few good starter questions to investigate.  It is a bit of detective work. Again, I think from your description and photos that this is something stressful in the plants environment rather than a bona fide infectious disease.  You may want to visit with your neighbors or folks at your local garden center/nursery. These folks may be able to help ID the source.

Regards

Steve

---------- FOLLOW-UP ----------


cucumber plants   QUESTION: Dear Steve,

Thank you for your help it is very much appreciated, we have checked the neighbours and they have no problems with the same type plants, unfortunately out local garden centre could not help, and living in the Highlands of Scotland we have no other help near to us, so I need to try and sort this myself.

I hope you do not mind helping me a little more with this investigation; I have answered the questions you asked below.

No weedkiller has been used inside or outside.

I have no heating in the GH just heated propagators to get seeds started.

The plants are in all areas of the GH and intermixed with other plants that are okay.

Nothing added to soil except compost, and did not have any problems like this before

The one factor that I will check is all the plants are in new compost purchased this year, I have now got a different brand and will see what happens with this, I have also planted a test of all problem plants outside, at the moment they are just started to grow.

No sure if this helps discover the problem but I sowed some radish direct and the come through well and all looked healthy, after 8 days the nice green leaves started to lose colour and over the next 4 days completely died. It is the same story for all the problem plants I have sown, it has also now happened to the 120 Swede sowings same story started growing well then went the same.

Besides trying the new compost and sowing direct outside have you any other suggestions that I could try?

I have attached one photo of cucumber plants that give more detail of that happens to the leaves.

Thank you again for your help

Ken regards
Ken

ANSWER: Ken:
Did you buy your compost through an individual or is it a bagged/commerically manufactured product? Some types of weedkillers can stick around in compost/manures.

It does require a little detective work. The photos of the cucumber still did not look like a disease, but something the plant picked up from the soil.

Good luck- keep me posted.
Steve

---------- FOLLOW-UP ----------

QUESTION: Hi Steve,

Thank you again for getting back to me, the compost is a bagged/commercially manufactured product.

I will let you know what happens to the new compost I am now testing.

Kind regards
Ken

Answer
Ken:
If your compost is a commercial product, it is unlikely that there is any contaminant that may be causing a problem. It would be best if someone could examine your individual situation in person.  Some of your neighbors who also have been growing veggies may be able to take a look at your plants and offer suggestions, but I feel that seeing those plants may be the next important step.

Regards
Steve