Sweet potatoes rate the attention of home gardeners wherever they can be grown. That includes territories beyond their range as an important farm product, such as Connecticut and southern New York.
During the last 25 years, we have grown them in various kinds of soil. Though the vines grow luxuriantly in the Summer rains or were stunted by drought, they never faded to produce a crop.
Differences in Moisture Content
One of how sweet potato varieties differ most is in their moisture content when cooked. Some are rather juicy, others almost as dry as Irish potatoes.
We have been growing three varied kinds to suit most tastes.
Moist Type Varieties
- Puerto Rico, with red skin and orange-colored flesh
- Nancy Hall, a rich golden yellow when cooked
- Yellow Jersey, a dry-fleshed, light-yellow variety
All three make excellent candied sweet potatoes. However, we prefer Yellow Jersey for baking in the skin and serving hot, with butter.
Methods of Planting
Sweet potato plants are not set out until all danger of frost has passed. We always set ours on ridges, a common practice in commercial culture, but they do well on level ground where there is no soil drainage problem. Rows should be spaced 3 to 3 and ½’ feet apart.
Fertilizers containing a high percentage of nitrogen are not satisfactory for sweet potatoes. because they result in excessive vine growth and a smaller number of potatoes, many of which are overgrown “jumbos,” decidedly inferior to those of moderate size.
A good fertilizer to use is one containing 4% nitrogen, 8% phosphorus, and 8 to 12% potash. This may be used at the rate of five pounds to 100 feet per row.
Set Plants on Ridges
When the plants are to be set on ridges, the location of each row is marked with a shallow drill in which the fertilizer is placed, and a ridge is then made above it by moving soil toward the row from both sides.
For plants to be set on level ground:
- A furrow at least 6” inches deep should be made.
- Mix the fertilizer with the soil in the bottom, where the roots of the plants will not come in contact with it when they are set, and the furrow can then be filled to the top with soil.
These preparations should be made a week before the plants are to be set.
The tops of the ridges are raked off before setting the plants, leaving a flat surface some six inches higher than the surrounding ground. Plants spaced about a foot apart are set in holes made with a dibber or pointed stick.
In pressing soil to the roots, be sure the hole is filled to the bottom. The plants must be watered unless rain is imminent at the time they are set.
Cultivate the soil between the plants lightly with a hoe after rains until this can no longer be done without injuring the plants. Then, deeper cultivation between the rows is continued until the vines meet between them.
Proper Digging Time
In sections where the growing season is long enough for sweet potatoes to mature fully before frost, they should be dug when the leaves start to turn yellow, indicating that underground growth has been completed.
Where the season is so short that the potatoes must be left to grow as long as possible, they may remain in the ground until the foliage has been blackened by frost, but the vines should be cut off at the earliest possible moment thereafter, and the crop dug the same day.
Use Spading Fork
A spading fork is the best digging tool for the average home garden crop. However, the potatoes must be handled carefully to avoid bruising or breaking the skin, which is very tender after digging. Hard, dark spots form in the skin wherever it is broken.
As the potatoes are taken from the soil, they can be spread out to dry in the sun for a few hours, after which a gentle brushing will remove most of the clinging soil. Then place them in slatted crates to move indoors and store them where the air is warm and dry.
Curing Takes a Week
Sweet potatoes are not at their best for cooking until they have been cured for a week or so. They will remain in good condition most of the Winter, but toward spring, they are apt to start getting “pithy.”
When more have been produced than can be used before they reach that stage, the surplus may be canned, after curing thoroughly, for use during the Spring and Summer.
Once you have started growing sweet potatoes, you may want to propagate your plants. Healthy, well-formed potatoes of average size are considered best for propagating stock. However, it is satisfactory to use some that are smaller, though they should not be the immature “strings.”
Start Early in the North
In Northern states, where an early start is needed to take full advantage of the growing season, the sweet seed potatoes are planted in hotbeds about a month before the last killing frost is expected.
It is also possible to start enough plants for a few rows from potatoes bedded in garden flats in the house.
In Southern states, where for general purposes, there is no advantage in starting the plants before the weather is warm and settled, the seed potatoes may be planted in beds without sash protection or bottom heat.
The potatoes are laid flat, with a little space between them, so the plants will not be too crowded. They should be covered with about three inches of soil, which may be a sandy loam or leaf mold; we generally use the latter. The type of soil under the potatoes is less important than that it be well-drained.
Best Stage For Pulling And Setting
The plants are at the best stage for pulling and setting when they have four to six joints, well-developed leaves, and a good supply of roots on the underground part of the stem. They should be grasped low and removed from the parent potato with a quick sidewise jerk.
44659 by Richard Leon Spain