How to make seedlings of the sweet potato

Sweet potato

In Japan, sweet potato seedlings are sold in the home center from around the end of April.

Are they selling the seedlings at the home center abroad?

Sweet potato seedlings mean grown vine of the potato.

The vines of sweet potatoes are growing up and making seedlings from harvested sweet potatoes in your kitchen garden of the last year.

You can make seedlings of sweet potatoes by growing the vines from harvested sweet potatoes in your kitchen garden.

That’s why, I will introduce how to make seedlings of the sweet potato.


Making the sweet potato seedlings by growing the vines


In Japan, the seedlings of sweet potatoes are sold only vine of it at home centers.

This means that Seedlings shop grows sweet potatoes in the greenhouse, and cuts out the growing vines from planted sweet potatoes.

When we cultivate sweet potatoes in your kitchen garden, sweet potatoes make it grow the vines that can used as the seedlings of sweet potatoes.

  1. Plant the sweet potatoes before the cultivation season in the greenhouse
  2. Sprout the sweet potatoes as vines
  3. Cuts the vines growing from sweet potatoes
  4. Plant the cut vines of sweet potatoes

If you think about the landscape of sweet potato cultivation for a moment, you’ll understand, but if you grow it casually, you’ll easily overlook where it comes from.

Germinate the sweet potato


Now, I’ll start to introduce how to make sweet potato seedlings.

The above photo is harvested sweet potatoes in my kitchen garden last autumn, the sweet potatoes have already started to sprout.


When planting the sprouted sweet potato, it makes vines to grow.

These vines can be used for the sweet potato seedlings as I already introduced and so many vines are sprouted from sweet potatoes, that you can take care it many seedlings from one planted sweet potato.

Incidentally, sweet potato grow the vines not using own stored nutrients but it grow the vines by supply from nitrogen-fixing bacteria like legumes.

So, you can plant only the sprouted part of the sweet potato by cutting it and you can take it to enjoy deliciously dividing the rest part.


Recommend sterilization of sweet potatoes before the sprouting process

Sweet potatoes have a disease called Alternaria leaf spot, which is caused by a type of thread-like mold that causes the potatoes to turn black.

If sweet potatoes for seedlings have an Alternaria leaf spot, it will be contagious to growing vines of sweet potatoes, so I recommend sterilization of sweet potatoes before the sprouting process.

The time for sterilization is as follows;

  1. Alternaria leaf spot: keep 47~48 degrees for 40 minutes as seed potatoes and 15 minutes as seedlings
  2. Black scurf: keep 47~48 degrees by 40 minutes as seed potatoes and 15 minutes as seedlings 

You can sterilize to seedlings after cutting them from vines of sweet potatoes when you have forgotten the sterilization before planting.

I think it is a little difficult to keep the temperature by 47 to 48 degrees for sterilization because it should be kept at a delicate temperature that does not boil.

Cut the sweet potato that it sprouted and grow the vines


The sweet potatoes will be sprout when it a long time holding after harvested.

The sweet potatoes already sprouted because I held them in the cardboard for three months that they harvested in my kitchen garden, so I planted them in the plastic bottle planter filled with thin water.

I will grow them in plastic bottle planters until becomes spring because the season in Japan is just winter now.

As a side note, sweet potatoes are categorized in Convolvulaceae which do not have poison in their vines and they can be eaten with no problem.

But not all Convolvulaceae plants are nonpoisonous, at least sweet potatoes with sprouted can be eaten safely.

Buds tend to emerge from the top and are difficult to emerge from the bottom

The buds of sweet potatoes tend to emerge from the top which means topside of planting in soils.

Conversely, the bottom side is difficult to sprout from them.

I was surprised there is a distinction of sweet potatoes between top and bottom.


Regarding the above photo, the top of sweet potato is left side of photo and the bottom is right side of it.

I have compared the bud direction with some of the sprouted sweet potatoes but I could not find the buds from the bottom side.

I think not all of the bottom of sweet potatoes are not to sprout but the probability of buds are very low, so I recommend eating the bottom side of sweet potatoes by cutting it off.


The leaves are opening after planting the planter for a week


After being planted in plastic bottle planters for a week, the leaves of sweet potatoes are opening.

It looks like cute red colored stalks and leaves of brilliant green.

I don’t remember the variety clearly, but I believe this potato is Kintoki.


And this potato is Anno sweet potato which has red stalks and leaves.

Kintoki has a red color similar to that of sweet potato, but Anno sweet potato is more like a sweet potato with a slightly lighter pigment and is characterized by its orange cross-section.

  1. Kintoki: Sweet and orthodox sweet potato
  2. Anno sweet potato: Characteristic orange colored cross-section and so sweet

Both sweet potatoes are very delicious but our family favorite Anno sweet potato than Kintoki because it is sweeter than another one.

In terms of sweetness, Anno sweet potato is stronger, so I think Kintoki would go well with things like tempura.

Replanted in the ground after growing a month by a planter


The leaves of seedlings smoothly grow after sprouting for a month.

I have replanted the sweet potato seedlings to the hotbed of stepping because it’s a hassle to grow in a plastic bottle planter.

Anno sweet potato is in the front, and Kintoki is in the back.

I hope it grows well, but what will happen?

Cut off the vines of sweet potato seedlings after growing on the hotbed since two month


Passed the two months after replanting the sweet potato seedlings to the hotbed of stepping.

It was still cold when I planted them in early March, but thanks to the warmer weather in May, the trees are now thriving.

The season becomes enough to warmer to plant the sweet potato, so I cut off the vines growing sweet potato.

Even so, the red leaves of Anno sweet potato have become completely indistinguishable.

Cut off the vines of sweet potatoes from the root


Pushing through the thick leaves, cut off the vines of sweet potatoes from the root.

I recommend cutting off the vines above the root node to harvest several times of the vine seedlings.

This time, it seems enough vine seedlings could be harvested, I have cut off the vines from the root.


I have got the sweet potato vines about ten after finishing cut off.

The vines that are sold in the home center, typically seem a little wilted but these vines are so fresh.

I was able to successfully complete everything from sweet potatoes to making seedlings!


Planting the sweet potato vines in soil under until the three nodes


Let’s plant the sweet potato vines in the kitchen garden.

The sweet potatoes can grow well even in poor soils, I have planted the vines not adding the manure.

The method of plant, I have chosen the diagonal planting to harvest many sweet potatoes.

If you would like to harvest big sweet potatoes, I recommend planting them by vertical planting.

The reason why influence planting method for the harvest of sweet potatoes size is based on the distribution of nutrition to adventitious roots coming out from a node from the nodes.

  1. Diagonal planting: soiled the nodes of vines about 3~4.
  2. Vertical planting: soiled the nodes of vines about 2.


First, plug in the rod in the soil, then plug in the vines of sweet potato in the hole by plugging and covering them with soil.

I think planting sweet potato seedlings is very simple and easy any other vegetable seedling.

The sweet potato seedlings can be taken roots not so much watering, I have watered them moderately.

After planting the sweet potato seedlings, I will only wait for the harvest season of them.

I think the cultivation of sweet potatoes is very easy with no management effort to grow.

Let’s make seedlings from sweet potatoes

This time, I have introduced how to make seedlings from sweet potatoes.

I have used the sweet potatoes that were harvested last year, but you can start to make seedlings from what you bought them.

When you start to make seedlings from the sweet potatoes that you bought, I recommend keeping them warmer place until sprout the buds.

Sweet potatoes are planted around May to June, so if you want to start making seedlings, you’ll want to start around March.

It will taste more delicious when you harvest the sweet potatoes which make seedlings from sweet potatoes yourself.

If you are interested in how to make seedlings from sweet potatoes, please give it a try.