Friday, October 3, 2014

Why do my Tomatoes need Phosphorus?

Tomato Principe Borghese 100mm pots

2 weeks ago these Tomatoes looked like this

and we had no idea what to do.

We had thought back in July when we were trying to produce a few extra early plants for the die hard Tomato growers that it was just too cold and too dark this year. I still have no doubt that cold and dark were a factor but they were just not getting better.

In the back of my mind was a concern that this was a response to a change I had made to our potting mix fertilizer program.  I had taken out all the Super Phosphate to harden the plants up and keep them from bolting away too quickly... well that worked! In fact it has worked really well with beets, lettuces and herbs but the change was aimed at improving our Tomatoes.  To fully appreciate what I have tried to do you need to do two things 1. visit your local supermarket and look at the Tomato pots they have for sale... they have been heavily treated with growth regulators so they can then be fed for luxurious growth without bolting away and 2. Phosphorus (P in the trio of major nutrients Nitrogen, Phosphorus and Potassium - NPK) encourages stem elongation and luxurious growth. Unfortunately it also is essential to root development so we need some Phosphorus for our Tomato plants to develop properly, especially when it is cold and dark.

Having decided that Phosphorus was the source of our problem I found a liquid formulation to give our Tomatoes a boost... we tested with some caution at first and happy that we had seen a positive response treated more widely and more heavily.  Bad move, we burned all the treated plants, that's the marking you can see on the leaves above.  Thanks to a knowledgeable supplier (Thank you Bruce Wallace) we tested a less aggressive P solution with the extraordinary result you can see in the top picture.  Tomatoes are back on the availability list!

And we now have a great tool for encouraging new root growth in plants that might be otherwise stressed.  Silver linings.

Carnation Super Trooper Velvet on Pink

Carnation Silver Pink, fresh on the list this week.

No comments:

Post a Comment

Meet Garden Bloggers