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.

2011 Sweet Potato Harvest

Last year I started my sweet potatoes very early. I bought the potatoes from a local grocery store and had the slips growing in the ground between April and May. They slowly took off and grew all over. Although I did add some fertilizer to the plants over time and the fertilizer was low in nitrogen the vines took over. Pretty soon they took up more space then everything else. While selling some cucumbers at the farmer’s market I was approached by an individual who was interested in buying my sweet potato crop. About a week later I excitedly turned over my soil to discover only half a dozen very small tubers. In contrast, this year I bought one sweet potato that was grown locally. I began planting the slips later – between June and July. No fertilizer was added and very little was done to take care of them. However, this year’s harvest was much better – I still need to buy a scale but I estimate the weight at least 5 pounds if not more.

My 2010 Sweet Potatoes planted in late April -  Poor crop

2011 sweet potato patch hiding behind squash & beans

My 2011 crop from 1 potato planted very late.

Meeting with an Heirloom Star

Last Christmas my wife did something wonderful and enabled me to go to California to visit my family. While I was there I went to Baker Creek’s “seed bank”, an old bank in Petaluma that was converted to a retail storefront for Baker Creek Heirloom seeds. When there I happened to meet and get a picture with Jere Gettle. He is the gentleman who started and owns the expanding business. He seemed to be a pretty nice ordinary guy. I asked him his opinion of several asparagus bean (Chinese Long Bean) varieties. I also asked him about possible shade options for my tomatoes. He was at a loss as to what could grow tall enough. Then I asked him if he knew of anyone who sold Jerusalem Artichokes (Sunchokes) in the area. Another employee, I think Paul, told me of a local farm that carried them. At that, my family and I bought the seeds I selected and we headed off to get some Sunchokes. And that is my claim to fame in the world of Heirlooms.

Me and Jere Gettle at The Petaluma Seed Bank

The Local Climate

Here in Tucson there are two things you can count on: heat in June and cold in January. Water is also a concern here because of the high mineral content of the tap water and rainfall can be unpredictable. A 50% chance of rain in July means that 50% of the city of Tucson will get rained on while a 50% chance of rain in December means that all of Tucson will receive rain 50% of the time. Some believe that we have more than the four seasons than more moderate climates experience. If that is true, then I would have to say that we have 5 seasons that overlap somewhat: hot, cold, wet, dry, and windy. Because we live in a desert we cannot count on having a pleasant fall or spring. Over the course of a few weeks in “the spring” it can go from the 60s and low 70s to the mid 90s while in “the fall” it may go from 90 and 100 to the low 70s in under a fortnight (2 weeks). Though the dramatic swings in temperature do nothing good for the tomato plant the long stretches of cold and hot favor a long growing season for both cold and hot loving plants.

After the unbearably hot dry summer comes the Monsoon weather

During the long winter spinach, lettuce, carrots, peas, garlic and other greens do very well. Broccoli, cabbage and onions also flourish but need to be started early if growing from seed. The long hot summer benefits crops such as okra, eggplant, Chinese Long (or Asparagus) beans, Black-eyed peas, hyacinth beans, Asian and Armenian cucumbers, sunflowers, corn, watermelons, cantaloupe, peppers, butternut squash, sweet potatoes, and zucchini. Oh- and tomatoes- if you can figure out how to save them from destruction. Certain limitations guide my selection in summer crops. My family doesn’t care for okra or eggplant, corn needs big blocks to pollinate well, Squash Vine Borers destroy my zucchini, lace bugs are determined to destroy my sunflowers, while cucumber beetles are always more work then the number of cantaloupes I get from my plants. So that leaves me with beans, watermelon, peppers, sweet potatoes, butternut squash, cucumbers, and – if I plan right – tomatoes. As most gardeners, I try not to look at the calendar as much as the soil temperature when determining what and when to plant.



Snow is a not too common - from February 2011




The kids are excited for snow while my garden is excited for water.



Research - An Informative way to select cultivars that will Beet the competition

A Cylindra Beet in my garden

I love beets. Especially butter beets. It took me a while until I found a beet variety that I liked. Most were round and became hard quickly. Being a gardener that does not like to take chances, I prefer to research my vegetable varieties before growing them. Some vegetables, such as finicky tomatoes and cucumbers in the summer must be researched based on an individual’s climate. However, I can use information about other more forgiving crops, such as beets, from researched conducted in another climate. That is why I like the following websites. The first is Cornell’s Vegetable Varieties for gardeners, which gives individual gardener’s advice on specific crops from various regions. The second is Dave’s Garden Plant files, which also gives gardeners the opportunity to rate a crop. And finally, the grand finale is a searchable database of results of test growing of individual vegetable cultivars from The University of Saskatchewan in Canada. In any case, it was from the Saskatchewan searchable database that I learned about the incredible productivity and taste of the Cylindra, Formanova, or butter beet. And I am so glad I did.

To those who ask about gardening in Tucson I say, "It is a science". That is yet another reason for my blog title. Though this is true for growing many things here, growing beets is a cinch. If you give beets enough water when they are starting out you can start them in early September-October when it is 90 degrees outside and they will happily grow until March- April when it is 90 degrees outside again. How I wish my other crops grew as easily as beets! Another plus about beets is that you can eat both the top and the bottom- though we usually give away the tops to another family (whose children appreciate them more) after my family has our first serving of them.

Think tender buttery texture in the form of a beet.

Even this beet possessed a smooth texture.