Sweet potatoes very skinny
Red fingerling slips. Soil mostly fully composted horse manure. On a hill so good drainage. Planted 8” apart. Most look like orange roots. A few 1” in diameter. Last year had large ones in a different location and planted this close together. It last year most eaten by voles. Discouraged. Planted over 20 slips. What would you suggest for next year?
There are a number of factors that may contribute to thin roots:
Sweet potatoes need 80-90 days from transplanting slips to full size roots (depending on cultivar).
If the soil is mostly composted manure it's possible that excess nutrients produced leaf growth at the expense of storage root growth.
Although the garden soils drains well we had an extraordinary amount of rain during the growing season. Organic matter holds moisture, so it is possible that plants suffered from excessive water.
We understand that you had better luck last year with your sweet potato harvest with the same 8-in. spacing. However, we recommend at least 12 inch es between plants.
Don't give up! Sweet potato is a wonderful and versatile plant.
Thank you. Appreciate the response.