In The Garden: Growing Sweet Potatoes

This is a great time to be growing Sweet Potatoes in the garden. They don’t mind the weather this hot,and as long as they are in well drained soil they can take whatever rain we are getting. Sweet Potato slips planted now (July) here in S. Florida would be ready in time for Autumn dinners, and if you started some slips now you could be making home grown sweet potato pie for winter holiday dinners with friends and family.

Sweet Potato, Ipomea batatas is native to South and Central America and is in the Morning Glory family. It is not related to the yam. Sweet Potato slips can be started at home. You need a Sweet Potato that will grow. For that purpose I bought Organic Sweet Potatoes, but my neighbor who did not buy an organic sweet potato brought me one that was full of slips that had sprouted in her cabinet (It’s been hot here, so that doesn’t surprise me). A slip is a stem with leaves that grows out of a sweet potato that is growing. To stimulate growth in a Sweet Potato lay it down in a bowl of water or wet coconut coir, or stand it up in a jar of water on a sunny counter top. I have done all three and I think laying the potato down in water has given me the most slips so far, although I am getting slips from all three methods. Once a slip is grown about four or five inches long I snap it off of the potato at it’s base and either put it into water or a 4″ pot of loose potting mix, or directly into the garden. You will lose fewer if you root them first, but you should not wait too long after potting to plant them. We just want them to grow a few roots, but we don’t want them to be pot bound when we plant them. When potting or planting the new slip allow the soil to cover a great deal of the stem.

Sweet Potatoes like sandy well drained soil and warm weather. Slips should be planted every 12″. They will make vines that grow along the ground, and where the nodes touch the ground new roots (and potatoes) will form. Nodes are the bumpy part of the stem where the leaf comes out. Most people hill or mound the soil they plant into, and leave about 3′ from the center of one mound to the center of the next. If it is not raining you will have to water them daily for a week or so until, they are established. This is also a good time to pour on a little fish emulsion or worm manure tea. Those liquid feedings will help to stimulate healthy root and leaf growth. Once established sweet potatoes should only be watered in the case of drought. Over watering will ruin the root crop.

Sweet Potatoes need 100 to 120 days of growth before harvest. They should be grown here well before any threat of frost as they are not likely to survive a frost . Mine are growing in a (straw mulched) mound which is a good idea for drainage, and when it is time to harvest it will be easier to find them without damaging them with a garden tool. Several weeks before harvesting the potatoes should not get any watering which will work well if you plant now. By harvest time we should be well into our dry season.

The sweet potatoes once harvested can be left out on the soil in the sun for a couple of hours to dry and then will need 10 to 14 days of curing in a warm room (85 degrees warm) before you can store or use them. It is best to harvest before any threat of frost because exposure to frost can damage the crop. If the plants are burned down by a frost cut the vines away from the roots as quickly as possible and begin curing the sweet potatoes. Curing as suggested helps to build the sugars in the sweet potato and hardens it for storage. Potatoes that have been exposed to frost are not likely to store well, so they should be cured and used quickly. Once they have been cooked into something they can be canned or frozen just fine. Ideally Sweet Potatoes are stored at 55 degrees f. We don’t have basements here in S. Florida, so we don’t have a good household environment for cool root storage, fortunately baked mashed sweet potato stores beautifully in the freezer and will make great pie once thawed.

Sweet Potatoes are lovely vining plants with heart shaped leaves. They will make a real nice house plant or outdoor potted plant if you have some extra slips.

Best of luck with your sweet potatoes.