What Potato Plants Look Like Through Their Growing Season

Learn how to identify a potato plant through its growing season and how to know when to harvest with this guide. 

Potatoes scientifically known as solanum tuberosum, are part of the nightshade family. It can be tricky to identify potato plants for home gardeners since the tubers grow underground and the green foliage on top has tomato-like blossoms. Learn the lifecycle of the potato plant so you can have a bountiful harvest in your own garden! 

Growing your own potatoes is easy to do when you learn about the lifecycle of the potato plant. Plus, you can continue to grow potatoes every year saving your own seed and you will no longer need to buy them at the grocery store! They can be stored for long periods of time and can last you all year with the proper techniques. Learn more about planting potatoes and potato varieties here.

Seed potatoes vs potato seeds

Planting with seed potatoes is the most common way to plant potatoes. Seed potatoes are when potatoes grow little sprouts on them. You can plant them underground and they will sprout a new plant and grow new potatoes. It is recommended to plant potatoes in the early spring, or about two to four weeks before the last frost. The ideal conditions for potato plants are well-drained soil and a cooler soil temperature, although they like full sun with at least 6-8 hours of direct sunlight a day. 

Potato seeds are very, very small. They come from the small green fruits, or berries, that are filled with hundreds of tiny seeds that grow near the potato flowers on the plant. They almost look like green cherry tomatoes! But, this part of the potato plant is not edible. This small poisonous berry has high amounts of solanine that can make humans very sick. The only edible part of the plant is the tubers that grow underground. You can plant potatoes from seeds this way, or you can plant them from seed potatoes. Most people will just plant seed potatoes, If you are interested in breeding your own variety of potatoes, that is likely the only reason you would use a potato seed instead of a seed potato. 

Potato sprouting

You will see your potato plants sprouting in about 3 to 6 weeks after planting the seeds. The sprouts will have small green leaves with one or two leaflets and will grow into compound leaves. At this point, there are no tubers being formed underground yet. 

Hilling during the leaf development

Once the potato plant is about 6 to 8 inches tall, you will want to do something called hilling. This is when you take soil or other organic matter, such as mulch, and “hill” around the stem of the plant on the soil surface so that only the top leaves are sticking out of the ground. This helps promote new tubers to grow underground and ensure higher yields. If you run of dirt to hill your potatoes add straw. Most gardeners will continue to hill potatoes hill the flowers produce. Once it flowers, there is no benefit to hilling. 

Flowering

Potatoes will reach their flower stage about 8-9 weeks after planting. During this phase of the plant’s life cycle, it will start tuber development underground. The potato leaves and foliage will start to reduce in height because it is now focusing its energy on the tubers in the soil. The flowers look similar to a tomato plant, but instead of being yellow, they are different in color. The colors of the flowers on the potato plant can vary depending on the type of potato. You may see bright pink, blue, or purple flowers, or they could also be white. The flowers are an indication that harvest time will be approaching soon. 

Dying

At the end of the growing season, the leaves and foliage will start to die or turn yellow. But don’t panic! This is a sign to know when it is the right time to harvest. If you harvest too soon, you may have underdeveloped or small potatoes. To make sure you get larger potatoes, you will need to wait until you start to see the plant dying. 

If your plant looks like all the leaves are missing but the plant is not dead, it is likely you have a problem with potato beetles. You should easily spot the beetles, but sadly since the pest will eat all the foliage, your crop will be drastically reduced if the beetles eat all the leaves, preventing the plant’s ability to photosynthesize.  

When to harvest potatoes

The easiest way to know when it is time for your potato harvest is at the end of the season when you notice the dark green leaves and foliage starting to die back and turn yellow. It is important to stay patient and wait until this time! You can harvest fresh potatoes anytime after the flowers are present, but they will not store well as the skins on the tubers are not hard until the plant has died back. Learn more about how to store potatoes with this post here. 

Troubleshooting and pest prevention

Some common pests for potato plants include Colorado potato beetles and green peach aphid. A common way to get rid of these pests is with Insecticidal soaps, but we like to hand pick pests here at Pleasant Grove Homestead.

We prefer picking Colorado potato beetles by hand, but it is important to find them as soon as you can because they are very vigorous reproducers. The yellow eggs under the leaves are hard to manage with sprays as well. We take out cups and pick them into cups and feed them to our chickens. we complete this task every other day. At the same time, we clip off any leaves that have eggs on the undersides. Our small children think it’s very fun to pick potato beetles and we make games out of it to see who can collect the most. We manage over 5,000 feet of potatoes with this method. 

You can also use specific sprays made for Colorado potato beetle like Captain Jack’s Dead Bug Brew,– but be early in your prevention. If you see five potato beetles there are already 100. 

Have questions?

Got questions about growing and storing your own potatoes? We may be able to help you troubleshoot! Send us a message on our contact page here!