why are my plants dying?

Asked July 29, 2017, 9:46 AM EDT

After receiving my soil test results (#6E2CZ4)I still do not know why my plants died for the past 2 years. I planted tomatoes, peppers and broccoli which slowly wilted and died even with plenty of watering. I replanted with fresh potting soil around the plant and last year they did ok. This year I still lost about 8 of 36 tomato plants. The soil test showed high potassium and magnesium (above optimum) and slightly above optimum in phosphorus. the fertilizer used was meant for lawns, 29-0-4 formula. How did the P, K, & Mg get so high? Is this why my plants died and what can I do to correct the problem? I have had gardens in this area for the past 20 years with no problem like these past 2 years.

Lapeer County Michigan

6 Responses

After looking at the soil test information, other than the high values of Potassium and Magnesium, the high pH stood out. The pH is very high and can affect the uptake of certain nutrients. A pH of 7.9 is above the preferred pH of the crops you indicated, especially broccoli. Nutrient toxicity is definitely a possibility. Not knowing the symptoms of the "dying plants" it is difficult to assess.

How your values of pH and potassium, and magnesium got so high may be a result of soil amendments. Some amendments can take time (months, years) to built up certain nutrients in the soil. These can cause values to slowly creep up to unfavorable levers. Natural amendments can vary greatly in the nutrients they supply.

Here are a couple of links that may be helpful.:

https://content.ces.ncsu.edu/extension-gardener-handbook/1-soils-and-plant-nutrients

http://pss.uvm.edu/ppp/pubs/oh34.htm

http://articles.extension.org/pages/63501/solutions-to-soil-problems:-soil-acidity

I hope this is helpful

To add to the information I previously supplied, the plants in question simply started to wilt the day after planting. They continued to wilt and turn brown & dry in spite of daily watering. I watered them extensively using the hose so I doubt it was due to drying out. The water from the hose is post water softener. Also each spring before rototilling and planting we burn the yard debris in the garden. Things like leaves, branches, dead material off of the previous years plants. Sometimes lumber scrap are also burned. Could any of these practices cause a cumulative problem?

trying to repost with better picture.

This is my garden now. You can see the two plants that died after a second planting with new soil.

The samples I submitted were all taken from areas where the second plantings had died. As you can see, after a slow start many of the second plantings are doing very well now.

There are several things to be concerned with. The "post softener" water along with the ash would explain the high potassium levels. The ash can also add to the magnesium and can rapidly push the pH up. The water softener is probably the bigger issue. This will increase the salt levels in your soil such that the plants will not take up water and die. Ruling out problems with pests and disease this could be your main problem. If the you had significant rains since your second planting (it doesn't appear that all the pictures came through), the rain could have leached out some of the salts allowing your new plants to thrive.