A few years ago when I began working with sweet potatoes, I preferred to grow out the slips from sweet potatoes cut halfway in a jar. However, as I have experimented with different techniques I have found that starting sweet potatoes in sand or soil is much faster, howbeit a bit more complicated.
|Putting Sweet potatoes out for transplants
|Placing the sweet potatoes in the Garden
|Purple Sweet Potatoes for Slips
So – what makes starting sweet potato slips in the garden tricky? Disease, nematodes, and various other factors have led to farmers to grow out small plants (or slips) from sweet potatoes rather than planting the tubers themselves. Transplanting sweet potato slips can be a rather simple process in a very moderate climate (where sweet potatoes do not grow well). In contrast, in hot southern climates (where sweet potatoes grow very well) transplanting can be much more difficult. This is because by the time the slips are ready to plant in May the 100ᵒ Fahrenheit (38ᵒ Celsius) daytime heat cooks the roots of the sweet potatoes down through the first 6 inches of soil. This means that either the roots must be very long or the plants must be given additional care until they establish themselves.
|All Purple Sweet Potato Slips
My experience this last month with growing and transplanting sweet potato vines has taught me that transplanting slips requires timing, hardening off, and recovery time. By timing I mean that I have found that it helps to transplant the slips in the evening. By doing this, it gives the roots a little more time to enjoy cool soil before the sun and heat begin to stress the plant. In very hot climates sweet potato slips need to be hardened off before they are exposed to the full sun. Until the plants stop wilting, temporary shading really helps to give the roots time to grow and helps to “harden off” the plant. Even with planting at night and shading, it may still take several weeks until sweet potato slips are ready for the intense heat of the Arizona sun.
|Sweet Potato Slips recovering
|More recovering Sweet Potato Slips
One other nonconventional means of transplanting sweet potatoes is the growing of sweet potato slips from tubers in the garden, then removing the tubers from the garden. This is the opposite idea of transplanting slips. With this method I mark (with a stick or some other marker) where I want to plant a very healthy disease-free sweet potato. Then, I put the sweet potato in the ground and cover it with garden soil. I then water it, just as she would any other plant in the garden. Next, I wait until the sweet potato grows out and the plant becomes established. Once the plant is about 18” long, then you carefully poke around for the potato and (with a fingernail or another sharp object) I remove any vines from the potato. Then I pull out the original sweet potato and fill in the hole with soil. With this method, you have to be very careful to keep from disturbing the roots of the growing slips. By doing this, you can keep from losing the 2-3 weeks of shock and recovery required when transplanting the sweet potato slips.
|Several weeks later - the vines have recovered
|Sweet Potatoes Started in the Garden - with tubers removed