Some thoughts about Tomato Diseases



Overwintered Tomatoes with Disease



I think it is completely ridiculous that we (gardeners and consumers) grow a plant that has so many problems and is prone to so many diseases. Although cucumbers have their fair share of diseases tomatoes take the cake. Cornell University maintains a good website to identify some of the major tomato and cucumber diseases. As if the tomato plant’s tolerance of only “mild” weather wasn’t enough, you cannot even plant them in the same soil for more than one season without getting diseases. My first major mistake with tomato diseases came in the early summer of 2010 when the compost that was my summer garden was not ready for planting in. So I decided to plant tomatoes in my winter garden that had just overwintered a crop of dying plants. I had been composting the old tomato waist and I’m sure some of the compost got on the plants. To make matters worse, I planted my tomatoes right next to a south facing wall. By the time June came around the radiant heat was making it so that I had to water several times a day. For those of you reading this – this is a perfect storm for any tomato disease – high temperature, diseased plants being composted, new plants being brought in, and lots and lots of water. Septoria spreads like wildfire. In my case, little black spots showed up on the bottom leaves then the leaves began to die. The fruit began cankering only where it touched the ground and sometimes not just when it touched the ground. Each tomato variety I had worked so hard to nurture through the winter began dropping its brown dried-up leaves from the bottom up. I later solarized but even solarizing only diminished the disease. It was a gardener’s nightmare! I have since learned a whole lot more about growing tomatoes – especially here in the desert.

Septoria - The king of Diseases - working its way up

In my opinion, Septoria is the king of the vegetable diseases. Yes – even worse than cucumber mosaic virus. It affects so many different crops and is transmitted through infected seed. Although I had some slight indications of it as recently as this last summer I believe that my mustard green crop will help me to wipe out this infection once and for all!

So – what is the proper way to take care of tomatoes once you notice disease? Remove any form of infection and throw it out. Do not compost, do not touch any other plant until you wash your hands and wash whatever touched the infected plant. Once you notice a plant really getting an infection you could go out and buy some forms of disease control but it is often better just to pull it out (roots and all) and throw it out. This is the shame of growing tomatoes – that they have been bred to produce delicious fruit while being so susceptible to disease.