It’s the last thing a gardener wants to see. Some foreign body growing in there with your tomatoes or other garden plants. Unfortunately, there is always a chance of local life forms finding its way into your garden. It blows in with the wind or washes in with the rain. There isn’t anything you can do to prevent it from getting in there. But what if only a certain plant variety has mushrooms growing right up next to it?
While every care is given to make sure seeds you purchase are free of spores, bacteria, molds and such, it can happen. For instance, this picture shows only beefsteak tomato plants suddenly sprouting mushrooms. Since the person is container gardening, and since all the soil was purchased in bags and produced by a reputable producer, it is fair to assume that the contamination came from the seeds. Or is it?
Upon examination of the remaining seeds, likely the unskilled eye could not tell if they were contaminated. There in lies the crux of the problem. As seed buyers, we rely on the seller to guarantee seeds are free of all manner of disease and infestations. This problem was the beginning of commercial seed companies research into how to prevent these issues.
There are regulations requiring testing of seed lots for contamination, but even if there weren’t, producers would probably test seed lots because their reputation is their business. Testing a seed lot does not guarantee seeds are free of contamination, but it is helpful. If seeds test positive for infestations, the entire lot is usually destroyed and an investigation as to where the contaminated seeds were produced. Which leads to the grower taking the necessary action to eradicate the contamination from the soil.
Not all seeds are sold by large producers. There are many other seed suppliers who offer seed catalogs online and by mail. Considering the amount of work that goes into producing seeds to harvest, and that they rely on return customers for their livelihood, it is doubtful sellers would knowingly sell bad seeds. Good intentions do not always lead to good results. Therefore it is important to pay attention when purchasing or ordering seeds.
Choosing organic seeds over “regular” commercial seeds. The only “organic” seeds planted this year were the beefsteak tomato seeds. They came from a national reputable grower whose seeds are sold in places like Wal-Mart and Lowe’s. Since this is a large company, it seems likely they tested the seed lots before packaging. None-the-less, we still have a contamination problem.
Purchasing seeds from a seed saver can be a way to get rare seeds. It can also be a way of importing any number of diseases and infestations. If you decide to take this risk take precautions with the seeds before and when you use them. Inspect the seeds carefully under a bright light. Compare them to commercially produced seed. There shouldn’t be a visible difference. Improper seed saving is evidenced by left over plant residue attached to them. They should not be discolored or misshapen. If you find any of these issues, ask for a refund. Or, if you decide to plant them anyway, choose a location far away from the rest of the garden to minimize the chance of contaminating your whole garden. (Remember contaminants can be carried a long way by insects and wind.)
When saving seeds from year to year, it is important to be sure you follow rigid standards and processes to insure the quality of your seeds. Make certain to remove all plant particles from the seeds and dry them according to best practices for that seed variety. Store them carefully. Seeds, as with everything else, can become contaminated while sitting on the picnic table uncovered.
In the event your garden is contaminated, depending on the type of contamination, you may be able to finish the growing season and harvest crops. It might be a bit more work. If you do this, it could be best not to save your seeds for that harvest. Instead rely on reserved seeds for the next season.
Fixing a contaminated garden can be accomplished by composting which allows the temperature to rise above 110 degrees. That should kill off anything you don’t want. This will likely mean you will lose whatever plant is in the section of garden since it is already contaminated.
This particular infestation is a mushroom found in the potting soil purchased by the gardener. The choice of seeds was not the culprit. The potting soil was produced by a national company that promises bigger plants guaranteed. The mushrooms are not harmful to the tomato plants, but could interfere with plant growth if they get too big.
If an entire garden plot needs treatment, perhaps the black plastic method will work for you. In this method you cover the entire area with heavy black plastic and weight it down. During the summer the heat intensifies and kills everything under the plastic from heat and lack of light. After removing the plastic, check for infestations and molds. Prepare the garden with treatments of mulch, fertilizer and so on as you would a new garden. This method is popular in arid and semi-arid climates and may not work for everyone in some climate zones.
Prevention is easier than fixing. Don’t use new mulch in the garden. Inspect compost before putting it on the garden for mold or other unwanted things. Only apply about two inches of compost to the top of your garden. Hopefully these methods will work for you.