Quality seed potatoes lead to a better potato harvest.

What to Dip Cut Seed Potatoes in Before Planting

by Benjamin Shorter

With their leafy green tops and underground harvest, potatoes (Solanum tuberosum) are simple to grow and provide a nutritious harvest. You grow them from cut pieces of potatoes saved for seed, called seed potatoes. Potatoes grow best in U.S. Department of Agriculture plant hardiness zones 1 through 7. Dipping the cut pieces in horticultural sulfur before planting them can help a late spring or early summer planting thrive. Planting in spring means a shorter growing season and colder, wetter growing conditions that make it difficult for potatoes to grow well.

1. Seed Potatoes

Seed potatoes are bred to be vigorous growers with many eyes that can take root, sprout, and become new potato plants. Seed potatoes are often bred, treated and tested to prevent transmitting bacterial or fungal diseases to your garden soil. As tempting as it might be, use only certified seed potatoes, not supermarket potatoes. In many cases, supermarket potatoes have been treated to never sprout. Certified seed potatoes are a step towards ensuring a healthy and problem-free harvest.

2. Preparation

After cutting the seed potatoes so there is one eye per piece of potato, you have the option of planting the pieces immediately, or allowing them to cure for a week. Both methods have benefits. Planting immediately reduces the risk of disease or rot forming on the cut sides, and the potato piece is of better quality and has a higher moisture content. Allowing the cut pieces to cure will give the chance for a callus to form, providing protection from damp, cold soil. Curing is suggested when doing an early spring planting, when the soil is wet and moisture-laden. If you cannot wait for the curing process, use horticultural sulfur to protect your cut seed potatoes.

3. Horticultural Sulfur

A powder more commonly used to lower the pH level of the soil, horticultural sulfur can be applied directly to cut seed potatoes. Horticultural sulfur will protect the pieces from diseases, particularly when potato pieces are planted when soil temperatures are below 40 degrees Fahrenheit. To apply, dip each of the potato pieces into a container of sulfur powder, ensuring all cut areas are covered. For large quantities, put several tablespoons of sulfur into a sealable plastic bag with the cut pieces and shake until they are all well coated. Be careful when using horticultural sulfur as the powder can lead to skin and lung irritation or problems. Wear gloves and a dust mask when using the powder.

4. Benefits of Sulfur

The sulfur powder will dry out the cut potato pieces, protecting them from wet and cold soils. The acidity of sulfur may help prevent potato scab from forming. Potato scab will lead to unsightly brown splotches on the potato surfaces.

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