How Much Water Does a Potato Plant Need? Finding the Sweet Spot for Irrigation

Potatoes are a delicious part of most gardeners’ diets. Eat them baked, fried, mashed, stuffed, or with or without a big pat of butter. They taste good any way. There are also easy ways to grow them in your own garden if you know how to take care of them properly.

Once they plant potatoes, many gardeners have questions about the best practices for watering potatoes. As with all garden vegetables, potatoes need to be watered regularly during the growing season to make sure they produce a lot of food.

How and when to water depends a lot on the climate in which you live. In general, most vegetable plants need 1 inch of water per week. I’ve written an extensive article with lots of details on watering your vegetable garden. Here we’ll cover watering potatoes specifically.

A thriving potato crop starts with providing plants the right amount of water at each stage of growth Underwatering causes stunted plants and low yields Overwatering breeds disease and poor tuber quality, Striking the ideal balance takes skill and vigilance,

When it comes to irrigating potatoes, follow these best practices on how much water potato plants need to stay happy and healthy

Water Needs of Potatoes Throughout the Growing Season

Potato water needs fluctuate depending on the plant growth stage. Tailor your irrigation approach accordingly:

Planting to Emergence (0-30 days)

  • Keep soil evenly moist but not saturated until sprouts emerge

  • Water immediately after planting to spur germination

  • 1⁄2 to 1 inch of water weekly prevents soil from drying out

Vegetative Growth (30-60 days)

  • Water needs peak during rapid foliage growth

  • 1-2 inches of water weekly keeps plants thriving

  • Let top inch of soil dry before irrigating to avoid oversaturating

Tuber Bulking (60-90 days)

  • Consistent moisture essential for maximizing tuber size and quality

  • 1-1.5 inches of water weekly, adjust for rainfall

  • Uneven water causes growth cracks, hollow hearts, malformations

Maturity and Harvest (90-120 days)

  • As vines yellow and die back, reduce irrigation frequency

  • Avoid overwatering close to harvest which can delay curing

  • Stop watering 2 weeks before harvest to toughen skins for storage

How to Tell If Your Potato Plants Need Water

Gauge soil moisture to determine potato water needs. Here are signs plants require irrigation:

  • Top inch of soil is dry and crumbly

  • Stems appear droopy or wilted

  • Leaves curl or take on a gray-green cast

  • New leaf and stem growth is stunted

Ideally, irrigate just as the top layer of soil dries out, before plants show water stress symptoms. Dig down an inch or two periodically to inspect moisture at root level.

How Much Total Water Do Potato Plants Need?

On average, potatoes require about 1-2 inches of water per week. This equals roughly 25-30 inches over an entire growing season. amounts may vary depending on:

  • Climate and weather patterns

  • Potato varietal

  • Soil type – sandier soils require more frequent irrigation

  • Planting density – closely spaced plants compete for soil moisture

  • Mulching – retains soil moisture, reduces water needs

Adjust weekly watering based on rainfall. If Nature waters your crop, you can reduce supplemental irrigation accordingly.

Best Practices for Watering Potatoes

Follow these tips to maximize potato production through proper irrigation:

  • Water deeply and infrequently to encourage deep rooting

  • Time watering for early morning or evening to reduce evaporation

  • Use drip irrigation or soaker hoses to target water to the soil, not leaves

  • Monitor soil moisture and irrigate when top inch becomes dry

  • Avoid overhead watering which can spread fungal diseases

  • Reduce irrigation frequency as plants mature

  • Stop watering 2 weeks before harvest to toughen skins for storage

Signs of Overwatering Potato Plants

While potatoes crave moisture, too much water causes major problems:

  • Rotting seed potatoes

  • Poor germination and weak sprouts

  • Excessive foliage growth but stunted tubers

  • Cracking, hollow hearts, and malformations

  • Increased disease and pest pressure

  • Delayed skin set, poor skin quality, bruising

  • Poor storing potatoes with faster sprouting and spoilage

As a golden rule, err on the side of underwatering rather than overwatering potatoes. Their tubers will tolerate some drought stress better than wet feet.

When to Irrigate Potatoes Grown in Containers

Container-grown potatoes need more frequent irrigation than in-ground plantings. Their soil dries out faster. Follow these tips:

  • Use containers with drainage holes to prevent waterlogging

  • Check soil moisture daily and water when top few inches become dry

  • Apply enough water so it drains from the bottom of container

  • Reduce watering frequency as plants mature

  • Move containers to shelter if forecasting heavy rains

Takeaways on Potato Water Needs

Mindful watering keeps your potato crop bountiful and nutritious. Remember these key points:

  • Peak water needs occur during tuber bulking around 60-90 days after planting.

  • Ideal irrigation provides 1-2 inches weekly, adjusted for rainfall.

  • Stop watering 2 weeks before harvest to toughen skins for storage.

  • Monitor soil moisture and refrain from overwatering which causes disease.

With a thoughtful irrigation approach tailored to their growth stage, your potato plants will thrive and deliver a robust harvest of delicious tubers.

What’s the Significance of a Potato Flower?

Potatoes are in the Solanaceae, or nightshade family, along with tomatoes, peppers, tomatillos, and eggplant. Eventually, when your plants have gained significant growth, you’ll notice the plants starting to flower. The plants have flowers at the tips of them. The flowers can be white, pink, or purple, depending on the type you planted. You can tell the difference between potato flowers and flowers from other nightshade plants if you’ve grown them before.

The potato flowers are a sign that the plant has started to produce tubers underground. Pollinators like bees love to visit flowers to get pollen, so you can leave the flowers alone and let the bugs enjoy them.

Sometimes, if the flower is pollinated, it will produce a small fruit that looks like a green tomato. These are poisonous (remember the Deadly Nightshade from Roman Times?) and filled with seeds. Just leave them on the plant and make sure children and pets aren’t picking them.

Usually around the time my potato plants are flowering, I’ve hilled them as much as I can. Now, I cover them with a thick layer of hay or straw and make sure they get an inch of water every week until it’s almost time to harvest.

When and How Often Should You Water Your Potato Plants?

Some of the links below are affiliate links. This means that if you click on the link and then buy something, I will get paid a small fee.

Potatoes like consistent moisture throughout the plant and tuber growth period. But, they don’t like to grow in soggy or extremely dry soil, so watering is a balancing act.

Ideally, do not let the soil dry out completely between waterings. Watering potatoes too little later in their life cycle often results in a smaller harvest. I don’t advise watering every day either, since potatoes could rot if they’re sitting in wet soil.

If the soil is drying out quickly, you can water it twice a week if you live in an area that gets very hot or dry. This is especially true if the soil is very sandy. This is not as much of a problem as it was before because as the potatoes get bigger, they tend to shade the soil and keep it moist.

Again, approximately one inch of water per week is ideal.

During the week, I keep track of how much rain my garden gauge has picked up, and if I need to, I water on Monday.

In most weeks, I choose not to water my garden if it rains an inch or more during the week. You can always use a trowel to give the ground a little push to see how wet it is still.

One thing I’ve learned over the years is that I have no idea how much water a rainstorm brings. That’s why a rain gauge is a more reliable measure of how much rain your garden actually received. Don’t rely on your “sense” of how much it rained, gather the actual data instead.

Here are some options for simple rain gauges. I like plastic over glass because the glass versions break very easily. I prefer taller gauges that won’t get covered up by the plants around them later in the season.

HOW OFTEN TO WATER POTATOES

FAQ

How often do I water my potato plants?

Generally, potatoes need between 1-2 inches of water per week; this could be provided by rain events or you to make up the difference. Water needs for your crop throughout its life goes a little something like this…

Can you overwater potatoes?

Risks of over-watering potatoes Early in the season, over-watering can result in misshapen tubers. Later in the season, it increases the likelihood of powdery scab and lenticel growth. “Applying too much water to crops can be just as detrimental as not enough,” says Andrew Francis, Senior Farm Manager at Elveden Farms.

Do potatoes need a lot of water?

Water Requirements Potatoes are quite sensitive to moisture stress over much of the growing season, so they need relatively high soil moisture levels (60-80% of the available water capacity) to achieve high yields and quality.

How many gallons of water does it take to grow a potato?

As a rough guide each potato plant needs about 10 litres, that’s just over 2.5 US gallons, to grow into. Cramming your potatoes in is a false economy, the result being very small spuds, if you’re lucky enough to get any at all. A typical garbage can-sized container would hold around four plants.

How much water do potatoes need?

Generally, potatoes require at least 1-2 inches of water each week without allowing them to dry out. Water needs for your potatoes during their growing season are as follows: From planting to 30 days: Low water needs. 30-60 days: Water is critical for vegetative growth and early tuber formation. 60-90 days: Water is essential for tuber bulking.

How long should you water potatoes before planting?

After figuring out how many potatoes to plant then getting them planted and giving them a thorough watering if your soil is dry, wait up to 2 weeks before watering again, as long as the soil doesn’t dry out completely. Keep the soil moist but not wet during these first 2 weeks.

How often should potatoes be watered?

Potato plants should be watered deeply, especially if the weather is scorching and dry. The soil should always maintain a moisture level of 8 to 10 inches underground. You should also ensure that you do not overwater the potatoes 2 weeks after planting. During the first weeks of planting, water after every 4 to 5 days.

Can potatoes grow in water?

Tips for growing potatoes in water: Ensure that your potato plant leaves don’t grow out of control when planted in the water. Potato blight is often caused by constantly wet leaves when they are grown in water jars. This is a disease that will result in flawed growth and rotten potatoes.

Leave a Comment