Are Your Sweet Potatoes Determinate or Indeterminate? Here’s How to Find Out

Potatoes in general can be of a lot of varieties and can be classified into either the determinate or indeterminate type. Determinate potatoes mature early and indeterminate potatoes mature late and have higher yields.  

So, that brings us to the question, “Are sweet potatoes determinate or indeterminate?”.

Sweet potatoes are the indeterminate type of potatoes. This means they grow for prolonged periods of time and keep producing throughout the season. The most common sweet potato types Beauregard, Bush Porto Rico, Centennial, Georgia Jet, Jewel, Vardaman and White Yam are all indeterminate types. 

But that is not all, to read more about sweet potato types, and how to properly grow them, read the article below. 

Basic Difference Between Determinate And Indeterminate Potatoes

Let’s discover whether sweet potatoes are determinate or indeterminate as we discovered what is brown balls in soil previously. Indeterminate potatoes have a prolonged growing season( 110 to 135 days)  and they produce all along this season. As a result, they have much higher yield than determinate potatoes. 

They also require “hilling” or mounding layers of soil on them. Thus, they need more maintenance work while growing. They have distinguishable  vines longer than seven feet. Below are shown indeterminate potato plants.

Determinate potatoes on the other hand, have a much shorter growing season ( 70 to 90 days). As a result, the yield is less than indeterminate potatoes. These potatoes are smaller in size than the other type and do not need to be “hilled”. 

Usually, these potatoes are red or white in color. The short bushes of this type of potato plant are shown below.

Sweet Potato Varieties- Whether They Are Determinate Or Indeterminate

Sweet potato variety	Time taken to mature
Beauregard	90 days
Bush Porto Rico	110 days
Centennial	100 days
Georgia Jet	110 days
Jewell	120-135 days
Vardaman	110 days
White Yam	100 days

Now let’s explore all the sweet potato varieties in details.

Beauregard:

This type of sweet potato is known to grow for a period of 90 to 100 days, and form short bushes. They have a rich, red skin, and can be harvested in spring, summer, fall and winter. In order to grow, it needs a tropical or subtropical climate. Thus, it can be classified as an indeterminate type of potato. 

Bush Porto Rico:

This sweet potato type has a slow growth rate of 110 to 120 days and only grows in spring or summer. The growing conditions require 65 F to 95 F degrees, and avid sunlight. The plant of Bush Porto Rico potato grows as tall as 1 to 2.5 feet. Having a high yield of 100 lbs per 100 foot row, this type of potatoes match all the major characteristics of indeterminate potatoes. 

Centennial:

These potatoes only grow in warm temperatures and take long periods of time to mature- 90 to 110 days. Their plants have vines and have to be planted in mounds of soil for good growth( this is called “hilling”. The outer skin of these potatoes are carrot colored and the potatoes themselves are large in shape. Thus, these potatoes are indeterminate potatoes. 

Georgia Jet:

The Georgia Jet potato plant is long and viny and takes about 90 to 110 days to mature. It tends to grow better in warm climates and has a high yield up to 100 lbs per 100 foot row. They will have a height up to one feet and are orange in color. All the criteria of this variety suggest that they are indeterminate type potatoes.

Jewel: 

This high yielding potato variety takes a very long period of time to mature, from 120 to 135 days. It grows best in a tropical climate and consists of vines. It does not have very long stems or vines, but the extremely long growth period confirms that it is an indeterminate type. 

Vardaman:

This potato type has a moderate growth rate of about a hundred days and high yield. However, it has a compact, bushy foliage and can be grown inside a container. It grows well in a warm environment, and has a short height of 6-10 inches. 

It has a yellowish-orange skin and can be grown in almost any soil. Although it does not have long vines, Vardaman sweet potatoes have more similarities with indeterminate potatoes than determinate. So, it is an indeterminate type as well. 

White Yam:

This potato variety grows in the form of compact vines, within a period of 90 to 110 days. And, they can stay on the vines like this for a while. But some vegetables like fully ripe tomatoes stay on the vine for few days only. 

They require a warm environment to grow and can grow from 10 inches to one feet. It is very different from other sweet potato types in terms of appearance and taste.

It has a pale skin compared to other orange colored sweet potatoes. This also falls under the indeterminate time due to maturing time and growing habits. 

Thus, all sweet potatoes fall under the indeterminate category. Hence, while planting it, it must be ensured that the procedure for planting indeterminate potatoes is followed.

Sweet Potatoes Growing Guide?

As discussed earlier, almost all sweet potatoes take considerable time to grow. So, you must have proper growing guide on hand. Additionally, the deeper the roots grow, the more produce you get. Hence, you have to bury the plant in layers of soil overtime.

When you plant your slips, make sure the temperature is at least 50 F at nightime. 

Firstly, you start by covering the potatoes with 4 inches of loose soil. Next, add about 3 inches of soil mixed with dead leaves and straw when the plant has grown up to 6 inches. Leave a small part- about 2 inches of the plant above the soil.

Sweet potatoes grow best in acidic conditions, in a pH of 5.5 to 6.5. Thus it is advised to add peat moss to the soil to make it acidic. You can use any organic granular fertilizer for plant growth. 

The soil has to be watered frequently for the first week at least,  until the roots are developed. However, keeping the soil watered well- an inch of water per week,  throughout the harvest will give better yield. 

You can harvest your potatoes after a maturing time of 90 to 120 days, depending on the potato variety you have chosen. It is recommended to harvest when the soil is dry and there is a lot of sunlight. 

After harvesting, you have to let the potatoes dry out but do not wash them with water. It has to be stored in a furnace room with open water pans to maintain a relative humidity of 90%. The temperature should be 85 F and under these conditions, the potatoes have to be kept for a week to cure. 

After the curing is complete you need to store the sweet potatoes in a dry, airy space at 

55 to 65 F. Do not refrigerate the fresh sweet potatoes as this will ruin their flavor. 

Frequently Asked Questions (FAQs):

What type of soil is best for sweet potatoes?

Sweet potatoes grow well in fine and deep sandy loam soil. The best growth comes from loose soil that is highly rich in organic matter. Therefore it is best to mix broken down compost and manure in the soil for planting sweet potatoes. 

How do you increase sweet potato yield?

You can increase sweet potato yield by creating conditions in your soil that increase sweet potato growth. Three weeks before starting plantation, you can set out silage or black plastic tarps to increase the temperature of the soil. In cold regions, it is advised to plant the potatoes under plastic tunnels in the soil. If it is clay soil, make ridges as high as 8 to 12 inches to heat up the soil and prevent floods. 

What makes sweet potatoes bigger?

In order to make the sweet potatoes bigger, the plant needs to be watered very well. However, watering techniques are also important. It is advised to water deeply with a gap of a few days in between instead of watering lightly everyday. You need to be mindful of how often it is raining. If it hasn’t rained for a long time and the soil is getting dry, you need to do extra watering. 

Conclusion

That is all you need to know to answer the question- “Are sweet potatoes determinate or indeterminate?”. Since they are of the indeterminate type, you need to be careful of the conditions that you are growing the sweet potatoes in. Follow the instructions provided to get the best yield and growth of sweet potatoes.