Soil splash is just as it sounds ... soil that splashes up onto your plants’ leaves. For plants like tomatoes, this can be the eventual kiss of death. The good news is, it’s almost entirely avoidable with just a little preventative effort.
When you first plant your tomatoes out in your garden, if you’re doing things right, you’re burying that main stem as deep as possible (or “trenching” the entire stem, if that’s your preferred method).
Burying tomato stems deeply is one of the practices that will give your plants the best start to a vast and healthy root system, and for becoming fantastic producers of that wonderful summer fruit. However, it also positions the leaves very close to the soil.
Soil-borne diseases like blight and leaf spot live in (you guessed it) the soil. When it rains, these diseases are being splashed up and onto the leaves and stems of your plants. Furthermore, muddy leaves cannot breathe.
The solution is simple: Bottom prune and mulch! About 2 weeks after transplanting your tomatoes, the main stem will likely have grown at least a few inches taller, and additional foliage will have grown as well. At this point, as long as you have ample foliage on the plant (see my video on Soil Splash below for a demonstration and example), remove the bottom 6 or so inches of leaves and stems (“bottom pruning”), as well as some of the inner growth.
Bottom prune any damaged or yellowed leaves/stems, any stems that are pointing down, and any stems that are touching the soil. Remove a few of the stems that are growing in toward the center of the plant as well.
Next, I highly recommend laying down a soil splash preventative mulch, such as weed-free straw.
This practice of “bottom pruning” will provide 3 immediate benefits to your tomato plant:
DAMAGED LEAVES: The bottom stems and leaves on a mature transplant will likely be “old” and perhaps yellowed and/or damaged. You will be doing your plant a tremendous service by removing these lower yellowed and/or damaged leaves, lest your awesome plant tries to be heroic and expends precious energy trying to fix them. Removing these lower stems lets your plant get on with the big, important job of flowering and producing.
AIRFLOW: Removing the lower 6 inches of stems (and later, once they’re bigger, the lower 10-12 inches of stems) will also provide a lot more air flow for your plant. Good airflow is critical to the health of your plant, whereas humid conditions are the perfect environment for bacteria and other diseases to grow and spread. Make sure to provide adequate air flow for your tomato plants all season long by staying on top of “bottom pruning.”
RAISING THE CANOPY: Removing the lower 6 inches or so of stems and leaves from your tomato plant will “raise the canopy” and make it much less possible for muddy soil to splash up onto your plant. (Thus, avoiding soil splash.)
Mulching around your tomato plants may not be something you normally think of doing, but if you do, you will reap 3 major benefits, both immediately and throughout the growing season:
STOPS SOIL SPLASH: Now that you’ve removed the lower stems and leaves of your plant, take it one step further and lay down a few inches of a preventative mulch, such as straw. (I recommend certified weed-free straw.) With a layer of mulch in place, when it rains, the muddy soil will have a very hard time splashing up on to your plants since the soil will be covered.
SOIL TEMPS & MOISTURE: A nice layer of a straw will keep the soil temperatures cooler as we head into the hottest part of the season. It will also help retain moisture, which is critical in drought-suffering areas like California.
WEED CONTROL: I can’t promise you won’t see a single weed if you have a layer of mulch in place, but I would be willing to wager a tall glass of lemonade that you will see significantly fewer over the course of the growing season. Plus it looks pretty.
Before we all head out to bottom prune and mulch our beloved tomato plants, I wanted to point out what will be obvious to some, but not so obvious to others. When bottom pruning, don’t go crazy. Don’t remove so much foliage that your plant has to nearly start all over growing leaves. Basically, don’t remove any more than about 25% of the bottom foliage because, remember, the leaves are where most photosynthesis takes place, which is critical for plant growth. You can always trim off more, but you can’t put it back. Kind of like a haircut.
And one last tip to avoid soil splash and spreading not only soil-borne diseases, but any disease that may already have found its way onto the foliage in your garden: Avoid overhead watering. Install a drip system, use a soaker hose, or simply be a very gentle hose-waterer. But at all costs, do not be an overhead-waterer.
As always, Happy Gardening! ~Karen/Love Your Land
Karen is a wife, mother, business owner, gardener, canner, and the owner of “Love Your Land.”
Karen understands that gardening in Northern Colorado is seemingly a fleeting moment in time, so join her on Facebook for daily tips, tricks, and discussions, and on Love your Land You Tube for weekly how-to videos on how to extend a 3-month grow season into a 9-month grow season!