What Is The Best Temperature For Growing Potatoes? (3 Tips)


Potatoes are a cool-weather crop and a staple of many people’s diets.  Although potatoes serve a wide range of uses in the kitchen, there is an ideal temperature range for growing them, and extreme cold or heat will lead to poor growth or small tubers.

So, what is the best temperature for growing potatoes?  The ideal soil temperature range for planting potatoes is 45 to 50 degrees Fahrenheit (7 to 10 degrees Celsius).  After planting, the ideal temperature for growing potatoes is 60 to 70 degrees Fahrenheit (16 to 21 degrees Celsius).

Of course, if the temperature is too high or too low, tubers will fail to form, or the plant’s growth will be stunted.  Potatoes are a cool weather crop, but the leaves and shoots above ground cannot tolerate a hard frost.

In this article, we’ll talk about the ideal temperatures for potato planting and growth.  We’ll also get into ways you can improve your yield by protecting potatoes from extreme temperatures.

Let’s begin.

What Is The Best Temperature For Growing Potatoes?

The best temperature for growing potatoes will depend on the growth stage.  We’ll start with planting potatoes.

Ideal Soil Temperature for Planting Potatoes

The best soil temperature for planting potatoes is 45 to 50 degrees Fahrenheit (7 to 10 degrees Celsius). 

sprouted potato
The ideal temperature for planting sprouted potatoes (or pieces if you cut them up) is 45 to 50 degrees Fahrenheit (7 to 10 degrees Celsius).

To be on the safe side, the University of Maine suggests waiting until the soil warms to 50 degrees Fahrenheit (7 degrees Celsius) to plant potatoes.

Planting earlier in the season, when the soil is cooler, will leave more time for the plant to grow and for tubers to form.

This is especially important for late-season potato varieties, which take a longer time to develop.  It is also important if you live in an area with a short growing season – in that case, you might want to choose early season potato varieties.

According to Cornell University Extension, 40 degrees Fahrenheit (4 degrees Celsius) is the minimum temperature for potatoes to sprout and germinate.  However, the University of Idaho suggests that any temperature below 45 degrees Fahrenheit (7 degrees Celsius) slows wound healing in potato plants.

To get around this, you can sprout your potatoes indoors before cutting them into pieces.  Then, wait for the cut potatoes to “heal” (form a harder layer) before planting them outdoors.

You can learn more about how to plant sprouted potatoes in my article here.

The table below summarizes the temperature ranges for planting potatoes, in both Fahrenheit and Celsius temperatures, along with some notes on each range.

Temp
Range
Degrees
Fahrenheit
(Celsius)
Notes
About
Planting
Minimum40
(4)
Potatoes do
not sprout
well at or
below this
temperature.
Ideal45 to 50
(7 to 10)
Wounds on
cut potatoes
will heal
faster above
45 degrees.
Maximum95
(35)
Roots do not
grow well
and tubers
do not form.
This table summarizes the temperature ranges for planting potatoes.

Ideal Soil Temperature for Growing Potatoes

The ideal soil temperature for growing potatoes is 60 to 70 degrees Fahrenheit (16 to 21 degrees Celsius).  Potatoes are a cool weather crop, so they prefer cooler temperatures for growth and development of tubers.

potatoes soil
Potato tubers form best in cooler soil at temperatures of 60 to 70 degrees Fahrenheit (16 to 21 degrees Celsius).

However, when soil temperatures stay low for a long time, the potato plant will grow more slowly both above ground and below ground.  This means less green growth above ground and slower tuber formation underground.

Although their growth will slow, potato plants can survive cold, and they may tolerate a light frost.  Even if a hard frost in the spring causes damage to your potato plants, all is not lost.

According to the Iowa State University Extension, new shoots will grow within 2 weeks to replace ones that are damaged by cold.

On the other hand, warm temperatures will also inhibit the growth of potato plants.  At a temperature of 86 degrees Fahrenheit (30 degrees Celsius), fewer roots will grow, and tuber production will practically stop.

The table below summarizes the temperature ranges for growing potatoes (producing tubers), in both Fahrenheit and Celsius temperatures, along with some notes on each range.

Temp
Range
Degrees
Fahrenheit
(Celsius)
Notes
About
Growth
Minimum32
(0)
Potato plants
tolerate light
frost. Shoots
regrow after
hard frost.
Ideal60 to 70
(16 to 21)
Maximum
tuber growth
occurs in
this range.
Maximum86
(30)
Fewer roots
grow and
tubers fail
to form
above 86 F.
This table summarizes the temperature ranges for growing potatoes.

What Temperature Is Too Cold To Plant Potatoes?

As mentioned earlier, potatoes will fail to sprout in soil temperatures below 40 degrees Fahrenheit (4 degrees Celsius).  Even if the potato is already sprouted when you plant it, the growth will be slow in such cold temperatures.

In addition to slow growth, potatoes planted too early in the season are subject to late spring frosts.  Although a cold-damaged plant can still send up new growth, it will cost precious energy to do so.

frosted leaf
Even if a potato’s shoots above ground do not survive frost, it can still send up new growth within 2 weeks.

Sometimes, you need to risk planting potatoes in the cold if you live in an area with a short growing season.  In that case, there are some ways to protect your plants from the cold.

How to Protect Potato Plants from Frost and Cold

When a sudden hard frost looms on the horizon, your potato plants just might be able to survive with a little help.  Here are a few ways to offer some extra cold protection for your potato plants.

Use a Cloche to Protect Potatoes from Cold

A cloche is a cover used to protect plants from wind, cold, and pests.  A cloche is often made of clear plastic or glass to allow sunlight through.

A cloche is kind of like a mini greenhouse, since it traps heat from sunlight in the air and soil beneath it.

You can make your own custom cloche out of a clear plastic bottle.  However, you will need a large plastic container to make a cloche that is big enough for established potato plants.

water jugs
Cut the bottom out of a large, clear plastic container to make a cloche for a potato plant.

To turn a bottle into a cloche, cut out the bottom and put it over the plant.  You can remove the cap on top of the bottle, and the opening will act as a vent.

You can also use wire to form a cloche, but this will not provide cold protection on its own.  However, you could then put a frost blanket or a piece of row cover over the wire cloche to keep the plant warm.

You can learn more about cloches in my article here.

Use a Row Cover to Protect Potatoes from Cold

If you have lots of potato plants, cloches might not be the most efficient way to keep them all warm.  Instead, you can try row covers to save you some time and effort.

A row cover is a piece of fabric material that is used to cover an entire row of plants at once.  A row cover protects plants from cold, and it can also keep pests out if you close up the ends of the row.

Hanging a row cover on plants can still lead to frost damage where the fabric touches the plant.  One way to avoid this is to install supports along a row.

Then, wrap the row cover over the supports.  For instance, you can use a flexible plastic rod to form a half-circle and drive the ends into the ground.

row cover
Drape your row cover over half-hoops made of plastic to create a miniature hoop house for keeping potato plants warmer.

Place your half-circles two feet apart in a row and then put the row cover on top of them, giving you a miniature “hoop house”.

Row covers will provide a few degrees of cold protection for your potato plants.  This can help the top of the plants to survive a hard frost, which saves you at least a couple of weeks of lost progress.

Add Mulch to Protect Potatoes from Cold

Mulching around your potato plants has two benefits.  First of all, mulch helps to insulate the soil, retain heat, and thus protects plants from frost.

compost bin
Hilling, or piling up mulch around the base of a potato plant, insulates against cold and keeps tubers from turning green and toxic.

Piling up mulch (hilling) is also necessary to keep potato tubers from turning green and toxic.  “Hilling” means to pile up soil or mulch at the base of a potato plant.

Hilling helps to keep potato tubers underground and out of the sunlight.  This prevents them from turning green and producing solanine, which is a toxic substance.

When Is It Too Hot To Plant Potatoes?

According to Yara, potato plants will not produce many roots at temperatures of 95 degrees Fahrenheit (35 degrees Celsius) or above. 

Even temperatures above 86 degrees Fahrenheit (30 degrees Celsius) may be too warm for growing potatoes.  According to the Department of Primary Industries and Regional Development in Western Australia, tuber development in potatoes comes to a near standstill when soil temperatures reach 86 degrees Fahrenheit.

Part of the problem is that a potato plant can still grow well in warm weather, but it may not form large tubers.

large and small potatoes
The small potatoes in the bottom (yellow) bowl were exposed to too much warm weather (or not enough sunlight for the plant).

In that case, you will see beautiful green shoots above ground during the growing season.  However, when you go to harvest your potatoes, you will find only a few small tubers, instead of the basket of large ones you were expecting.

If you live in a warm climate, there are a few ways to keep your potato plants a little cooler to help the tubers grow better.

How to Grow Potatoes in Hot Weather

Growing potatoes in hot weather starts before you even begin planting.  The first step is to choose the right varieties, and that means finding potatoes that are heat tolerant.

Choose Heat-Tolerant Potato Varieties

Here are some heat-tolerant potato varieties you can try:

Use the Straw Method for Potatoes

One interesting way to grow potatoes is by covering the potatoes with straw instead of burying them in soil.  According to the University of Illinois Extension, this method can keep the potato plants as much as 10 degrees Fahrenheit cooler while also reducing water loss.

straw bale
A layer of straw helps to keep potato plants cool.

You can learn more about how to grow potatoes in straw bales in my article here.

Provide Shade for Your Potato Plants

Any potato plant that gets partial shade during the hottest part of the day will stay a little cooler, which can mean the difference between large tubers and none at all!

Here are two methods to provide shade for your potato plants.

Plant Potatoes Near Taller Crops

Try to plant your potatoes near taller plants.  The exception would be tomatoes, since they are in the same family (nightshade) and they share diseases in common (such as blight).

For example, if you are planting cucumbers to climb up a trellis, you could plant a row of potato plants behind the row of cucumbers (place them so that the cucumber plants provide some shade).

rows of potatoes
Plant your row of potatoes next to a row of cucumbers or other tall plants to provide some shade for cooling.

As the cucumbers grow, they will provide some shade for the potatoes.  Just remember that potatoes do need some sunlight to grow and produce tubers.

Lack of sunlight is just one cause of small tubers on potato plants – you can learn about the other causes in my article here.

Use Shade Cloth Over Potatoes

Shade cloth is another way to keep potato plants cool.  Shade cloth is made from a mesh-like material that filters out some of the sunlight before it gets to your plants.

Some light is still able to get through shade cloth (the amount of light depends on the grade of shade cloth).  This means that your potato plants will still be able to grow.

Depending on the type of shade cloth, it can provide up to 10 degrees of heat protection for your potatoes!

This shade cloth from Gardener’s Supply Company can be used with hoops for support.

If you combine shade cloth with the straw method for growing potatoes, you can keep your plants much cooler, even in a hot climate.

Conclusion

Now you know the ideal temperature ranges for planting and growing potatoes.  You also know how to keep your plants a little warmer or cooler, depending on the circumstances.

I hope you found this article helpful.  If so, please share it with someone who can use the information.

If you want to read some of my most popular posts, check out the “Best of GreenUpSide” page here.  Enjoy!

~Jonathon

jonathon.david.madore

Hi, I'm Jon. Let's solve your gardening problems, spend more time growing, and get the best harvest every year!

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