Monday, July 21, 2014

Bringing Veggies back from the Garden Bed

This post is to follow up the terrible blight I had that destroyed the majority of the plants in my garden this summer.

What I felt I did right with this last disease outbreak: Each year I anticipate that something will get diseased and I plan for combating this in a variety of ways. By watering once every 4 to 5 days I reduce the amount of water that collects on the surface of the soil. Where there is no water interaction between the soil and the leaves of plants there tends to be much less disease. Every time I see dead or dying leaves on my tomato plants I pull and discard them in the trash. Instead of irrigating the plants by overhead watering, I water with a soaker hose. When diseased-looking beans were encountered, I pulled the majority of the leaves off the plant and discarded them in the trash.

Solarizing my Summer Garden

What I felt I did wrong: The local seed company I purchased my seed from is a nonprofit organization, and probably does no testing for disease. They most likely plant these beans in isolation and are not alarmed when plants wilt or die early. It is doubtful that this company treats seed with anti-bacterial agents or fungicides.

While I did pull diseased leaves from bean plants I did not ensure that the dead leaves that had fallen were discarded quickly enough.

Trying all sorts of things to get rid of the blight

How I reacted: Ripping out the majority of a garden is probably the best long term way to deal with rapidly-spreading disease. After pulling the plants, I added some fish meal to the soil, soaked the area by watering for hours before laying down a sheet of 5 mil plastic over the affected area of the garden. By watering and covering the affected area I am essentially “pasteurizing” the soil with a method called Solarization. This method kills both good and bad bacteria in the soil and requires weeks of furloughing the soil.

Another view of my summer garden while solarizing

Future Plans: Because the Rattlesnake pole beans I bought were very heat resistant and tasty I believe I will give this variety another try. However, next time I will be purchasing seed from out of state and putting them in a corner of my garden that is far from my tomato and cucumber plants.

Saving the diseased Rattlesnake beans to give back to the seed supplier

Though a spray application of diluted EM-1 was able to save the majority of my sweet potato plants (and reverse some of the effects of the blight) much like I had experienced before, EM-1 had less of an effect on the rest of my plants. I began a batch of activated EM-1 in an insulated very warm place and plan on applying this in water to my garden immediately after solarizing the garden. The philosophy behind this is similar to taking a probiotic (such as acidophilus and other healthy bacteria) shortly after taking an antibiotic intended to relieve a bad infection.

Unripe tomatoes in a bucket

A Legend or Celebrity Tomato

Some thoughts about treating bacterial diseases in the garden: Though there are many anti-fungal sprays on the market (such as those which contain potassium bicarbonate) antifungal does not always mean antibacterial. While it is possible to treat the leaves of some plants with an anti-bacterial spray, such as highly diluted rubbing alcohol, this is only a short-term solution to a larger problem. Just as a patient would be unwise to take only antibiotics every time he had a stomach ache, treating garden diseases with mainly anti-bacterial agents is, in the long run, bound to backfire - because some form of bacteria is always present in healthy soil. Introducing healthy bacteria into the soil on a regular basis is probably a more effective means of controlling disease.

Delicious Slices of Tomato

Friday, July 4, 2014

The Beans that Killed my Summer Garden

The pretty color of the Rattlesnake Pole Bean
For years I have been looking for a Phaseolus vulgaris pole bean variety that does well in our summer environment. Many other bean varieties do incredibly well in the Tucson Heat, such as the Chinese Long Bean (Vigna unguiculata subsp. sesquipedalis) the Tepary bean (Phaseolus acutifolius) and the Purple Hyacinth Bean (Dolichos lablab L.). Unfortunately, the Chinese Long Bean and Purple Hyacinth bean take a lot of effort to prepare while the Tepary bean is a natural carrier of bean mosaic virus - a disease I do not need to expose my garden to. The Phaseolus vulgaris or common bean tastes good for my family no matter how we prepare it (baking, boiling, stir-frying, steaming, eating raw).

Rattlesnake Bean Flowers

Having heard that Rattlesnake pole bean grows quite well in Tucson and knowing it to be a a Phaseolus vulgaris variety I obtained this variety from a local seed source this last winter.

Rattlesnake Pole Beans are quite productive

Top left leaves showing the first Signs of Diseased Bean Leaves

Without considering the potential consequences of planting a “native grown” variety in my garden, I planted out all the seeds in the packet. The purpose of a pole bean variety in my garden is to provide west-side shade for my tomato plants. This requires that the beans that I plant be completely disease-free, as any disease such as mosaic or leaf curl can spread like wildfire among some of the most virulent tomato plants. Out of the 50 plants Rattlesnake bean plants that popped up about 5-8 had leaves that looked wrinkled and deformed. These were immediately pulled from the garden and discarded. As the remainder of the plants grew, I noticed that many of the lower leaves died off. Though the premature leaf death of lower leaves is very similar to the Tepary bean the yellow leaves with brownish-gray spots was not.

Rattlesnake Beans Spreading Blight to Tomato leaves

Rattlesnake Beans (dead leaves) next to dying tomato leaves

Another look at the Rattlesnake Pole Beans next to Tomatoes

By the time I noticed the yellowing leaves and brownish-gray spots on my tomato plants it was too late. A bacterial blight spread like wildfire directly from the Rattlesnake beans to my Tomatoes and Purple Burgandy Bush Beans (also Phaseolus vulgaris) then to my cucumber-melons. Normally, it can be difficult to trace the direct cause of a garden disease. However, in this case there was a direct correlation between where these beans were growing and where the disease spread to other plants. Every day I went outside to pull branches, leaves, and plants from my garden. 

The characteristic circles and yellowing associated with Tomato Blight

Leaves of Tomato Plant experiencing Blight

Tomato Blight leaf remains exhibit wilted yellow/grayish leaves

When the disease finally began to spread to my sweet potatoes I knew that this was truly a bacterial blight and that the only plants I had a chance of saving were my sweet potatoes and Sunchokes. 

Blight effecting Sweet Potato Leaves

Once I was certain I had ascertained the problem I spent the entire next week measuring my progress not by how fast my garden plants grew, but by how fast I could tear my garden out.

After pulling Blighted Leaves

Ripening Tomatoes Under Shade cloth before pulling out the stems.