Hardening Off Sweet Potato Slips Is Crucial Before Planting

Skipping this step can lead to high transplant mortality rates, experts warn.

Apr. 3, 2026 at 4:05pm

An abstract, impressionistic scene of blurred, colorful sweet potato leaves and vines in soft, warm light, conveying the gentle, nurturing process of hardening off plants before planting.Properly hardening off sweet potato slips before transplanting helps the tender plants adapt to outdoor conditions and thrive in the garden.Weslaco Today

Sweet potatoes are a popular homegrown vegetable, but experts say the crucial step of 'hardening off' the slips (rooted sprouts) before transplanting them into the garden is essential for a successful harvest. Failing to gradually expose the tender plants to outdoor conditions can result in high rates of transplant shock and plant death.

Why it matters

Sweet potatoes are a versatile and nutritious crop, but they require specific care when transplanting from greenhouse to garden. Hardening off the slips helps the plants adapt to outdoor sunlight, wind, and temperature changes, improving their chances of thriving once planted.

The details

According to Juan Anciso, PhD, a professor at Texas A&M University, the hardening off process involves gradually exposing sweet potato slips to full sun and wind over 3-7 days before transplanting. This transition from the greenhouse's protected environment to the open garden is crucial, as skipping this step can lead to high mortality rates as the plants struggle with transplant shock.

  • The hardening off process should take place in late spring, before transplanting the slips into the garden.
  • Anciso recommends gradually increasing the slips' outdoor exposure from a few hours per day up to 8 hours per day over the 3-7 day period.

The players

Juan Anciso, PhD

A professor in the Department of Horticultural Sciences at Texas A&M University and a vegetable specialist at the Texas A&M AgriLife Research and Extension Center in Weslaco.

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What they’re saying

“If you skip this process then several of potato slips may not survive the transplant shock and they will die. Not all will die but a higher percentage will if you had not hardened them off.”

— Juan Anciso, PhD, Professor, Texas A&M University

“Hardening off of any plant (edible or not) means a gradual exposure to the sun and wind as these plants are coming from greenhouse conditions with reduced sunlight and wind.”

— Juan Anciso, PhD, Professor, Texas A&M University

What’s next

Once the sweet potato slips have been properly hardened off over 3-7 days, they will be ready to transplant into the garden. Gardeners should monitor the plants closely and water them more frequently in the first few weeks to help them adjust to their new outdoor environment.

The takeaway

Hardening off sweet potato slips before planting is an essential step that home gardeners should never skip. Taking the time to gradually expose the tender plants to outdoor conditions helps them adapt and thrive, leading to a bountiful sweet potato harvest.