Have I ever mentioned how important it is to keep good records of your garden experiments? ‘Cuz I sure wish I had ’em right now. This spring, on some now-unknown date, I planted an unrecorded variety of potatoes, very carefully, in two identical Potato Grow Bags. In one container, I planted a single seed potato. In the other container I planted three seed potatoes of that same variety. Now, the directions call for five seed potatoes in each 15 gallon grow bag, but that seemed crazy based on what we saw with the spacing of the All Blue potato plants last year. If we grew them that way, the potatoes would probably be tiny. But, if we cut back to just three seed potatoes, would that give us a better yield of good sized potatoes, or did we really need to go all the way back to just one seed potato per pot to get the best potatoes? Only one way to find out, so we grew some.
The bags were placed side by side and given the same amounts of compost and water. The two grow bags ended up with similar amounts of foliage, though the three-in-one bag flowered first and drooped earlier. I thought the potatoes were Rose Golds, and wanted to save some of them for seed, so I pulled the potatoes when the singleton had just started to droop in earnest.
The three-in-one bag had a dozen nice-sized potatoes and a handful of small ones, too small to save for seed, if I had been planning to save from that bag. This might be a fine harvest from this variety of potato, which I am now thinking is a California White. But I don’t honestly know. The label from the California Whites says, “Cal White is a long white-fleshed potato with brilliant white skin. Produces heavy yields of large potatoes.” Would you call this skin ‘brilliant white’? It’s certainly the whitest one we’ve pulled out of the ground here at Dirt to Dinner.
The singleton bag had seven big potatoes, and one tiny one, which together weighted 3 and 3/4 pounds, almost a pound more than the dozen potatoes from the three-in-one bag. Now, how many square feet is 15 gallons? The over-wintered potatoes produced just under 1 and 1/4 pounds of potatoes per square foot. The 15-gallon bag has an 18″ diameter…any math geeks out there? Ah, what the heck, even if we call it two square feet, they are doing well. In fact, it should have taken us over 3 square feet to get those 3.75 pounds of potatoes over the winter so I’m calling that bag a success. And the other bag is good too. It all depends on what you want. If you want big fat baking potatoes, or even just all the potato you can get out of a square foot, you might want to give the potatoes more room. If you want lots of small potatoes, you might purposely crowd them into the bed even though it may reduce your yield slightly.
Either way, it’s time for me to make some potato salad.
The experiments are fascinating. I love the tiny potatoes, and I’ve always wondered how the growing difference works. Even though I don’t have the space to grow my own potatoes, following your thoughts is neat to see. Do you think there might be a different result if the spacing tests were done on different varieties of potatoes?