The leaf of a potato leaf tomato. Photo: xwildflowers, garden.org
Question (from April 2019): A strange phenomenon occurred in my light garden. I sowed seeds of a heritage tomato called ‘Matina’ I picked up at a seed exchange and instead of tomato plants, potatoes came up. Does this mean the plant is a cross between a potato and a tomato? I know that potato fruits are poisonous, so will the fruits be poisonous or edible?
Answer: Your question threw me a first. I was about to answer that potatoes (Solanum tuberosum) and tomatoes (S. lycopersicum) don’t cross, even though they are both in the same genus, and that there had probably been a mix up at the seed suppliers. However, then I thought, isn’t ‘Matina’ one of “those” tomatoes? I’m referring to so-called potato leaf tomatoes.
Yes, not all tomatoes have the leaves with the multiple, deeply serrated lobes we’re used to. Some produce leaves with broader, smooth-edged and thicker leaves, often darker green as well, called potato leaves. Obviously, they aren’t potato plants, they just have leaves that look like potato leaves. ‘Matina’ is one of those tomatoes.
They’re not even such a rare phenomenon. Some very popular tomatoes, like ‘Stupice’ and ‘Brandywine’ are potato leaf varieties. I even found a web site that lists hundreds of potato leaf varieties: Tatiana’s Tomatobase.
And don’t worry that your “tomato that looks like a potato” will attract Colorado potato beetles (potato bugs). Its leaves may look like potato leaves to us, but they smell like tomato leaves and potato bugs are attracted by the odor of the leaf, not its appearance. They can smell a potato plant from nearly a half a mile (800 m) away, but aren’t attracted to tomato plants.
So, just plant your potato leaf ‘Matina’ tomatoes and enjoy their fruit: they won’t be poisonous.
The potato leaf gene is recessive: the plant has to inherit one from each parent for it to have potato leaves. If your plant self-pollinates, its seeds will have two copies of the gene and will produce plants with potato leaves. If ever it cross pollinates with a regular leaf tomato, it will likely produce tomatoes with regular tomato leaves.
Response (from October 2019): I did as you said and planted out my ‘Matina’ tomatoes and they were a huge success: the earliest tomatoes in my garden, yet they produced trusses of smallish, juicy, very tasty red fruits over the entire summer and well into fall. I’m very satisfied with the results.