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  • Mold on Potting Soil

    Created by joanna517 on

    I am new to gardening and bought 2 green houses. I live in the Lancaster, Calif desert where it is either very hot or very windy.

    My plants (tomatoes,peppers and misc herbs were doing very well inside the green house until I had to remove the tomatoes since they were so full and so high. I put them outside the greenhouses and now my thick tomato plants have thinned out and look terrible plus no tomatoes.

    That is a problem in and of itself but my herbs which I left inside the greenhouse looks like there is mold growing on the top soil of all my herbs as well as the onions, carrots and peas I planted that are all still left in the greenhouse. These plants are in direct sunlight from 6 am though 5 30 pm. I water once a day for the plants inside the greenhouse and twice a day for the tomatoes and peppers unless the temperature is above 80.

    What can I do for the mold on the plants inside the green house and what is happening to my beautiful tomatoes to make them so thin and sickly looking? Should I put them back in the green house? Is it too windy for them (some days about 20 mile an hour winds) most day between 75 and 90 degrees .

    PS…I used organic soil and fertilize every 3 months with miracle grow and had to use neem oil for something that was eating holes in the leaves. Pus I have a lot of white moths that keep coming back as well as a few flies. I know flies sometimes leave eggs but I am watching for bugs hence the Neem oil.

    I just don’t know why my luscious plants look so thin and sickly now. Can anyone help me with these two problems?…Thank you…Jo Ann

  • Author
  • #200351

    Eric Vinje

    I’d think that the change in light, heat or humidity is likely causing the legginess in your tomato plants. Tomatoes like pretty even temperatures, if it gets quite cold at night, 90 degree weather can stress out your plants. The soil/fertilizer you are using may also be the culprit if it contains high amounts of nitrogen. The miracle grow you are using likely contains high amounts of nitrogen, I’d refrain from using it on plants which you are trying to improve fruit or flower production. Consider adding a liquid fertilizer that is low in nitrogen and high in phosphorus to your weekly or bi-weekly watering regime.

    Wind would not be the culprit of legginess. With proper support structures, wind can actually help build the resiliency of tomato plants by strengthen the stems. These winds may actually be helping your tomato plants.

    The mold on your potting soil would not be of concern to me unless you noticing negative side effects on your plants. If anything, the mold indicated to me that your soil is “living” and a thriving ecosystem that’s encouraging healthy vegetative life. If you still would like to get rid of it, consider decreasing the humidity in your greenhouse. What kind of ventilation do you have in your greenhouse? Adding fans that will blow air below the plants can help decrease residual humidity near the soil surface. A top dressing of a copper sulfide based product would also help the problem. Bonide Garden Dust should fit your needs perfectly, find it here! https://www.planetnatural.com/product/garden-dust/

    Good luck growing!

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