There they are – straw bale garden potatoes, which at first sight are amazingly clean compared to tubers grown in the ground. The first bale out of seven harvested was disappointing. Almost every potato had developed deep cracks long before the plants started dying back, and all of what had been attached to one plant’s roots were a rotted, gooey mess. Obviously, that one got too much water, and I know exactly when and how it happened. Never grew potatoes before, so I wasn’t aware that the plants died when the tubers were ready. Yep, I thought that particular plant was somehow not getting enough water. Fixed that problem fast and thoroughly… only to experience hindsight in HD.
But why are the potatoes cracked?
I suspected a fertility issue, but it seems that at some point they got too dry, and since the fissures are well scabbed over or even covered with skin, this must have happened quite some time back. They’re still edible, just weird. There’s always a lesson in every garden season, especially when you try growing something new, or test out different growing methods, and here we’re doing both at once. Overall, I’m pretty happy at harvesting over a bushel of potatoes out of 9.5 bales. How many seeds did it take to grow this much? Including the one that was a total loss – 21, though there were a few other tubers with rotted spots thanks to my feast and famine watering of this crop.
The book says to plant 2 per bale, but 3 were a lot smaller than the other seed potatoes, so I put all those in one bale and broke the rules. Some people claim that planting large seed potatoes is the key to harvesting large tubers, so the little ones were planted separately to see if that belief is true. Not really. Even those undersized seeds produced at least one huge potato, though the rest on the root were smaller than those in the other bales, which is more likely due to crowding them more than it is to seed size. Odd, because they didn’t spread out in the bale – just grew straight up with loads of empty space between the two planted. Plant communication?
I was expecting potatoes on the small side, because Yukon Golds are always like that at the store, but I had potatoes so large that just one is a meal for two. Seriously. This one in the photo is about 6 inches wide. It’s not the only mega potato found in the bales. There were 1-3 on a root, mixed with a few average sized tubers, and a bunch of teeny weeny ones. Why not more uniform development? I learned that early nutrient levels are critical to potato size – like in the first weeks that the seed potato is sending out sprouts. And I was late in realizing the straw had hogged all that fertilizer used in conditioning the bales, and no Ocean Forest was used for planting the potatoes.
Still pondering how to best accomplish uniform fertility for potatoes in straw bale gardening…
Liquid fertilizing from the top is no doubt draining down to the bottom causing the deepest potatoes to have more of it available. I’m almost tempted to try popping the bales open to plant so some slow release nutrients can be applied between two wafers so the entire length of the root has those crucial nutrients when it needs them. Tying them back up tight enough might be tricky, but it’s worth testing. The only other way that comes to mind so far is some potting mix that contains nutrients to the hole before inserting the seed, though you might need to stuff a little loose straw in after the potato so the media doesn’t all fall out when you roll the bale back over after planting the potatoes. But that second idea still puts all the nutrients in the bottom of the bale.
Talk about an effortless harvest of root veggies! Just cut the twine, separate the wafers of straw closest to the main stem of the plant, and then pull the stem up to dislodge the tubers. Some will need picking of the root, and others you’ll have to search through the surrounding straw for to make sure you don’t miss any. Brushing them off works fine on some, but not all. At this stage the skin is very fragile too. It doesn’t take much friction and the skin rolls off super easily.
They say not to wash potatoes when you harvest them, and these are far cleaner than any other method of growing. Seems not necessary, except… there might be bits of moist decaying straw stuck to your harvest. Don’t assume you’ll be able to brush those off when the potatoes dry! It becomes one with the skin, and may possibly influence the flavor as the freshly ‘dug’ tubers cure.
The few days that passed between opening bale 1 and finishing the ‘picking’ was long enough to show me you can’t just leave the straw bits in place like dirt. So, yes, I washed the freshly harvested taters from 9 bales out of 10 to get all bits of straw off before letting them cure. It allowed me to gently roll it off with very little skin damage, and then left them on the mesh table to dry off on both sides. Probably an hour, before moving them inside onto spread out newspapers for curing.
Will the bath affect the storage life? Only time will tell, but I know they won’t taste like rotting straw. The potatoes taste great by the way. All those baby ones went into a huge pot of harvest vegetable soup. Growing them in straw didn’t change their flavor or texture, at least not unpleasantly. To tell for sure if they’re better tasting, a side-by-side comparison is called for.
Kind of glad all the red potato seed was gone when I got this far in planting. Yukon Golds have better shelf-life, and are an all purpose potato. Red potatoes are too moist for some recipes, and don’t store as well, still I’ll grow some reds too next year.
I’d be willing to bet that the cracks you’re seeing doesn’t have to do with water but actually Potato virus Y (PVY). New strains of PVY can cause significant suberized (“scabbed over”) cracking on many cultivars of potatoes. Where did you obtain your seed stock? Did you purchase certified pathogen-free seed? If seed isn’t obtained from a clean source, there is a much higher likelihood that it has accumulated virus levels in propagation (although, PVY can also be present in certified stock as well).
I’m happy to comment more on this!
-M.S. student in Plant Pathology studying PVY
Hi A.B. –
There’s an interesting concept. Especially given that my dad had the same problem in soil last year with only 1 out of several kinds of potatoes. He too decided it was bad seed. I just bought what was available at a local garden supply place. I wasn’t worried about it being certified pathogen-free… had no idea they should be!
Incidentally, does this also cause the brown spots or cavities in the interior that most of these potatoes developed? Or is that some other issue?
Yep it can