Many plants can be either determinate or indeterminate. In terms of potatoes, determinate and indeterminate growth as a lot to do with how the foliage, flowers, and berries grow (yes, potatoes have berries). It has very little to do with the actual tubers themselves. While this distinction may make little difference in the garden, it is fascinating to look at how potatoes actually grow.
Determinate potatoes generally mature quite quickly so they are usually early- to mid-season varieties. The plants are fairly short and produce most of their flowers at one time.
Indeterminate potatoes are often late-season varieties that need longer time to mature, and the plants continue to grow bigger with longer stems and lots of flowers. While they can produce a slightly larger yield, their continuous growth refers to the plant itself and not the potatoes underground.
Unfortunately, there is a lot of misinformation circulating about how the determinate and indeterminate plants will produce potatoes differently. But these two types of potatoes grow tubers the same, and you can cultivate them the same, too.
To better understand the difference between determinate and indeterminate potatoes, we need to first look at how potatoes grow.
How Potatoes Grow
When you plant a potato in the ground, the eyes sprout into long stems which become the above-ground foliage of the plant. When it matures, the plant flowers and produces berries. These berries contain seeds that you can use to grow more potatoes.
Underground, the plant sends forth roots to draw nutrients and water out of the soil. Potato plants also send out underground runner stems called stolons. The potatoes that we harvest and eat are not actually roots. They are tubers, which are swollen members of these stolons.
When distinguishing the difference between determinate and indeterminate potatoes, it mostly has to do with the growth of the foliage, the flowers, and the berries.
Determinate potatoes are relatively new in the world of agriculture and were only introduced in the last few hundred years.
The main characteristics of determinate potatoes are:
- Plants are usually only about 1 meter (3 feet) tall.
- Early season varieties.
- Flowers are produced at end of each stem, and then the stem stops growing. This is why determinate varieties are often shorter.
- Fewer flower clusters.
- Will only produce one crop of berries for a short period of time.
Many gardeners unknowingly grow determinate potatoes because they want potatoes that have a shorter maturation and produce tubers earlier.
Indeterminate potatoes have been around for a long time. Some of them will grow to be over 2 meters (6 feet) tall.
Because of the tendency for indeterminate potato plants to grow very long and sprawling, this may be why potato plants are commonly referred to as ‘vines’.
Indeterminate potatoes are generally defined by:
- Long maturation time. Most late-season potatoes are indeterminate.
- They produce flowers on lateral stems, and then the main stem continues to grow and produce more laterals.
- They will grow and flower for a long season and produce new berries all the time.
- Potential for higher yield and larger potatoes
Many claim that as an indeterminate variety grows more and more laterals and berries, it will produce more and more potatoes. Other sources will often use generic terminology like “continue growing indefinitely” to give the appearance that indeterminate varieties will continue to produce additional layers of potatoes. This is not the case.
Determinate VS Indeterminate
The main difference between determinate and indeterminate potatoes is foliage growth. Determinate potato stems stop growing once they produce berries, while indeterminate potato stems can continue to grow.
How Determinacy Affects Tubers
In short, whether a potato is determinate or indeterminate has little affect on the tubers.
As a potato grows, its solons will continue to produce tubers but will stop once it reaches maturity. This is true for both determinate and indeterminate. Many of the late tubers do not have time to fully mature as harvest approaches which is why there are those little tiny potatoes hidden underground at harvest time.
An indeterminate potato may have a higher yield as it has a longer growing season which allows more of these potatoes to reach a harvestable size. Consequently, an indeterminate potato has more foliage for photosynthesis which, coupled with the longer season, can help some of the later potatoes to grow larger. Unfortunately for most of us, our season is not nearly long enough for this to make any significant difference.
Does Determinate or Indeterminate Make A Difference In The Home Garden?
Whether you are growing determinate or indeterminate potatoes makes absolutely no difference in your garden (unless, of course, you are interested in producing potato berries).
Both types of potatoes are grown the same, and they can benefit from planting in trenches and hilling. Also, all potatoes grow very well in the garden or in grow bags.
Deciding Which Type To Grow
When deciding which type of potato to grow, choose a variety based on the flavour, texture, and storability that you prefer, and don’t worry if it is determinate or indeterminate.
Of course, the ‘days to maturity’ is an important factor in determining which type of potato. In our Zone 2b garden, our season runs from about May 21 to September 15 which barely gives us enough time to make the most of a late-season potato, so most of the varieties we grow are incidentally determinate.
It is rather difficult to classify a potato variety as determinate or indeterminate. This is because most varieties are intermediate, meaning they are neither one nor the other and share characteristics of both.
Because the differences are not easy to define, most seed companies will not mention if a variety is determinate or indeterminate.
While there is no way to create a definitive list, we have included the common varieties that are usually defined as either determinate or indeterminate.
|Determinate Potato Varieties||Indeterminate Potato Varieties|
Does It Really Matter?
There is a lot of debate over whether potato plants should be left to flower or not. The disadvantage of removing them is you never get to see a potato plant in all its glory. Whether your potatoes are determinate or indeterminate, the flowers are beautiful, ranging from white to subtle shades of pink, and fragrant.
The difference between determinate and indeterminate potatoes is purely academic and makes little difference to the grower. So rather than get caught up in what you are growing, just get out there and enjoy the beauty, and bounty, of your garden.
This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.
© 2022 Bellwether Farming