Hollow heart in potatoes
An open cavity in the middle of potatoes is a defect known as hollow heart.
Many gardeners grow potatoes in their vegetable garden, and some are dismayed to find they have some potatoes with a seemingly unexplainable problem. When they cut the potato in half, there is an opening or cavity in the middle that’s either angular-, star- or lens-shaped. Sometimes the cavity is ringed with a brown discoloration, and other times it is just a gap surrounded by normal potato flesh. Or, it may be just a dark spot in the center of the interior. Michigan State University Extension horticulture educators and Master Gardener hotlines receive questions about this when the potatoes are headed for the dinner table. Before this, nothing is visible.
This cavity in the middle of the potato goes by the interesting name of hollow heart. It sounds more like a romance problem than tuber trouble. Some gardener’s first thought is some kind of insect or disease caused the gap. Smart gardeners realize the exterior of the potato has no marks or blemishes and there is no damage to the flesh of the potato. This open area was created by a third classification of problems called physiological or abiotic problems. It was not caused by anything alive. Hollow heart occurs because of uneven amounts of moisture during tuber development or a combination of other environmental factors.
Hollow heart, sometimes called brown heart or sugar center, is found everywhere potatoes are grown and occurs when there is an abrupt change in growing conditions. It often has to do with lack of water causing slowed potato growth and stress, and then an abundance or overabundance of water. This allows the potato to grow too rapidly, causing the center to pull apart, or simply, the potato split its pants.
The single opening in the center is more common in round potatoes, but in large or oblong potatoes, there may be two cavities formed closer to each end of the tuber. Research has shown that nutrients and cold soil temperatures can factor in. Some research has shown that if the hollow heart has brown, internal edges, it happened early in the potato’s growth. Openings that are not darkened happened closer to the potato’s harvest. This is why it is important to keep moisture in the soil during dry periods. Checking soil moisture several times a week during dry weather and watering deep enough to keep the soil moist can eliminate or prevent separated centers.
Hollow heart does not affect the taste, quality or nutrition of the potatoes. It may affect their use because potatoes with hollow heart are not suitable for making potato chips. With plenty of butter, however, hollow heart potatoes make fine mashed potatoes.