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Q. I live in Maryland. We have had a lot of rain in the past week. I have 2 different type tomatoes planted in containers on my deck: "Beefsteak" and "Early Girl." My Beefsteak started growing little root-looking or potato-eye-like things up the stem. I moved the plant away from the Early Girls, but sure enough my Early Girls are growing the same thing right now. I have no idea what this is. HELP! Can you tell me what these root-like growths are on my tomato plants?
A. You're describing root initials, also called adventitious roots, tomato stem primordial, or (our personal favorite), bumps on stems.
They start as hundreds of tiny hairs up and down the stalk. Hairs can turn into roots when buried underground. Above ground, they form tiny bumps which are the beginnings of roots.
Root initials emerge on a tomato stem as a result of stress – most often when there’s a limit or blockage in the stem’s vascular flow.
Blockages are caused by a number of things, including high humidity, overly wet weather, over-watering, internal injury, poor drainage, or other root injury. Often the blockage is water-related. So your recent wet weather explains the sudden onset of root initials.
The good news is that root initials pose no harm to plants. You can even mound extra topsoil or compost around the base of your plant, covering the lower root initials, and they will push deeper into the soil, creating a stronger root system.
You can prevent root initials next year by planting tomatoes in well-drained soil or raised beds.
Learn more about root initials or bumps on stems.
Good Luck and Happy Gardening!
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