Southwest Ohio - planting zone 6a
In this video we will discuss our strategy for growing sweet potatoes in straw bales and harvest the two straw bales in which we grew sweet potatoes. We prefer growing sweet potatoes in straw bales for two main reasons: 1. the straw initially heats up when it is being conditioned, so is generally warmer than even our raised bed soil in late Spring when we plant our sweet potato slips and 2. harvesting is so much more fun and easy, just break apart the bales!
The straw bales are conditioned in a similar way to all our other straw bale plantings. We start with straw that was verified free of persistent herbicides. Make sure it is straw, not hay as hay has weed seeds. We purchase our straw from a local farm so we can monitor what is sprayed on it prior to baling.
Conditioning the straw is the process of charging the carbon rich straw with nitrogen and beginning the composting process. We use large bags of lawn fertilizer, just make sure it is ONLY fertilizer and has no other additives. The schedule for conditioning the bales we use is: Day 1: completely saturate the bale with water only. Day 2: apply about 1 cup of fertilizer and water in with about 3 gallons of water. Day 3: 3 gallons of water only, no fertilizer. Repeat the every other day cycle for 7-10 days. You will see the bales heat up and then come down in temperature, usually within 2 weeks of starting the conditioning. The bales are then ready to plant in.
Even with just two straw bale plantings sweet potatoes do command a lot of space in your garden. So place your straw bales off in a corner and expect about a 10ft radius of sweet potato vines coming off of them.
Harvesting is easy, just break apart the bales! No digging and the sweet potatoes are mud free when they come out. The only down side we saw this year is many of the sweet potatoes wrapped around each other and were hard to separate, but this is likely just because so many grew in such a small space! Perhaps in the future using a large square bale rather than two small bales would work better.
If you have any questions, please let me know in the comments!
-Peter