Temperature plays a critical role in the life cycle of a potato, especially during the sprouting stage. Understanding the temperature ranges at which potatoes sprout can significantly impact your growing success. In this comprehensive guide, we’ll explore the various stages of potato sprouting and how temperature influences each stage.
Armed with this knowledge, you’ll be well-equipped to optimize your growing conditions for a bumper crop.
Stage 1: Initial Sprouting at 39°F (4°C)
This is the temperature where biochemical processes in the potato tuber kick in. Cellular respiration starts, converting stored sugars into energy for growth. However, it’s a minimal response and can often go unnoticed. The eyes, or buds, of the potato, may show a slight swelling. Given that many other factors like soil humidity are controlled, this temperature can initiate the sprouting process, albeit slowly.
Stage 2: Visible Sprouting at 45°F (7°C)
In this range, you will notice the first real signs of sprouting. The eyes that started to swell in Stage 1 now begin to elongate into discernible sprouts. The starches in the potato begin to convert more quickly into sugars that feed the growing sprouts. It’s a sign that your potatoes are ready for more serious growth. However, this stage can still take up to two weeks or more for noticeable changes, depending on other growth conditions like moisture and soil quality.
Stage 3: Vigorous Sprouting at 50°F (10°C)
This is often considered the sweet spot. Sprouts not only grow but do so with gusto. You’ll see multiple stems and leaves forming from each sprout, a clear sign of a thriving plant-to-be. This robust growth ensures that once planted, the sprouts will turn into strong plants capable of a higher yield. The energy conversion from starch to sugar is at an optimal rate, and nutrient uptake from the soil is at its best.
Stage 4: Rapid, but Risky Sprouting at 55-60°F (13-16°C)
Here, you’re stepping into tricky territory. While sprouts do grow faster, they are not as sturdy and can become leggy, or long and weak. This means the plant is expending energy on stem growth at the cost of root development. Without a strong root system, nutrient and water uptake will be compromised. Additionally, the higher temperature makes the potatoes more susceptible to diseases like soft rot and other bacterial infections.
Stage 5: Declining Quality at 65°F (18°C) and Above
Past this temperature threshold, sprout development becomes erratic. The sprouts that do grow are generally weak and more vulnerable to disease and rot. This is not an ideal temperature range for sprouting potatoes. The high temps accelerate metabolic activity, but this often results in “burnout” where the potato exhausts its stored energy quickly, resulting in poor-quality sprouts.
Do Potatoes Stop Sprouting Below 4°C?
Potatoes generally do not sprout below 4°C (39°F). At temperatures below this threshold, metabolic activity in the potato is significantly slowed down or virtually halted. Sprouting is inhibited because the cellular processes required for growth are dormant or sluggish. This is why it’s crucial to store seed potatoes in an environment that doesn’t drop below 4°C if you intend to sprout them.
What Temperature Does Potato Seed Die?
Potato seeds can die if exposed to temperatures below freezing, generally around 0°C (32°F) or lower. When the water inside the cells freezes, it leads to cellular damage, often rendering the potato unviable for future growth.
Similarly, extremely high temperatures above 30°C (86°F) can also kill potato seeds due to heat stress. It’s crucial to store seed potatoes within a safe temperature range to ensure their viability.
What Is The Safe Storage Temperature Range?
The safe temperature range for storing seed potatoes is between 35°F and 50°F (1.7°C and 10°C). Within this range, the potatoes remain viable and are less likely to suffer from diseases or spoilage. This temperature range also helps maintain the potato’s internal moisture and sugar levels, ensuring better sprouting when planted.
For more information on how to successfully encourage sprouts for planting see my article “How to get potatoes to sprout eyes” or watch the summary video of the article below.
Summary
In summary, potato seeds have specific temperature requirements for optimal sprouting and growth. They start sprouting at around 4°C, with the rate and quality of sprouting improving up to 10°C. Temperatures below 4°C generally halt sprouting, while storage below freezing can kill the seed. For safe storage, keep seed potatoes between 1.7°C and 10°C. Understanding these temperature guidelines is crucial for successful potato cultivation.
