What Do Potato Leaves Look Like? A Guide to Identifying Potato Foliage

As a home gardener who grows potatoes being able to recognize the leaves and stems is an important skill. Properly identifying potato foliage helps with monitoring plant health troubleshooting issues, and distinguishing potato plants from weeds or other crops. In this guide, we’ll explore the key characteristics of potato leaves to help you become more familiar with this important vegetable’s foliage.

Potato Leaf Shapes

Potato leaves are oval-shaped and can be either whole or divided into leaflets. Leaf shape can vary somewhat between potato varieties

• Whole, oval leaves are more common on wild potato relatives.

• Cultivated potatoes usually have divided, compound leaves made up of oval leaflets.

• Leaflets are arranged alternately along the stems and measure 1-6 inches long.

• There can be anywhere from 3 to over 12 oval leaflets per leaf.

• Leaf shape in potatoes is controlled by multiple genes, so there is considerable diversity.

Leaf Margins

The edges or margins of potato leaves can be smooth, toothed, or deeply lobed depending on the variety.

• Older potato varieties tend to have leaves with smoother edges.

• Many modern potato cultivars have leaves with toothed or jagged margins.

• Deep sinuses or notches between lobes are sometimes seen, especially on terminal leaflets.

• Leaf margins may be slightly ruffled or flat depending on genetics and growing conditions.

Leaf Color

The most common leaf color in potatoes is a medium to dark green. However, other colors are possible depending on phytochemistry.

• Wild potatoes exhibit more color variation like purple, blue-green, gray-green, and variegation.

• Cultivated potatoes are usually solid green, but can range from light to dark green.

• Anthocyanin pigments can produce burgundy, red, or purple coloration.

• Chlorosis results in light green, yellowish, or white leaves.

Leaf Texture

Potato foliage has a smooth, velvety texture. The leaves are thin, but not tender like lettuce or other greens.

• Densely hairy leaves are found on some wild potato relatives.

• Most cultivated potatoes have smooth leaves with few if any hairs.

• A waxy coating on leaves causes a velvety or shiny appearance.

• Leaves are delicate enough to tremble in a light breeze.

Leaf Arrangement

The leaves of potato plants emerge alternately from stems and branches. The leaf arrangement is staggered, not directly across from each other.

• Stems and leaves emerge from the underground tubers and rhizomes.

• As new shoots develop from the base, leaves unfurl alternately along the stems.

• Lower leaves are smaller and spaced closer together than upper leaves.

• Leaves become progressively larger up each stem.

Compound vs. Simple Leaves

As mentioned earlier, potato leaves can be either compound (divided into leaflets) or simple (whole).

• Compound leaves with multiple oval leaflets are more common in cultivated potatoes.

• Simple, unlobed oval leaves are typically seen on wild potato species.

• Some potato varieties have a mix of compound and simple leaves on the same plant.

• Leaf type is an important botanical identification feature for distinguishing species.

Identifying Potato Foliage Issues

Knowing the normal appearance of healthy potato leaves allows you to spot potential issues when they arise:

• Wilting, drooping, or curled leaves indicate drought stress or disease.

• Yellowed leaves may be from overwatering, nutrient deficiencies, or viruses.

• Brown leaf edges or spots can be sunscald, early blight, or flea beetles.

• Defoliation is caused by Colorado potato beetles, hail, wind damage, or herbicides.

How Potato Leaf Traits Influence Yield

Certain leaf characteristics impact photosynthesis and can affect the yield potential of potato plants. Here are a few examples:

• Plants with greater total leaf area absorb more sunlight for energy production and tuber bulking.

• Dark green leaves contain more chlorophyll for higher photosynthetic capacity and carbon fixation.

• Deeply lobed or divided leaves have a larger surface area exposed to light.

• Healthy, vigorous foliage that persists longer in the season supports higher tuber yields.

• Potatoes with superior heat or drought tolerance maintain leaves longer before senescing.

Variations Between Potato Types

There are some noteworthy differences between the foliage of cultivated potatoes, wild potato species, and hybrids:

• Wild potatoes typically have simple, oval leaves with smooth margins.

• Modern potato cultivars often exhibit compound leaves with toothed leaflet edges.

• Fingerling or heirloom potatoes may have a mix of simple and compound leaves.

• Hybrids can display unique combinations like deeply lobed leaflets.

• Foliage color, texture, and hairiness vary considerably between wild and cultivated types.