Sweet potatoes are one of the most rewarding crops to grow. They require very little attention during the season, spread into a lush ground cover of vines, and then surprise you with a hidden harvest underground. Even better, when harvested and cured correctly, they store for months, making them perfect for fall and winter meals.
As explained in the introduction on page 1, sweet potatoes are not actually related to regular white potatoes. They belong to the morning glory family, which is easy to see in their long trailing vines and heart-shaped leaves. Unlike upright potato plants, sweet potatoes spread across the soil surface.
Over the years, gardeners have gained access to many varieties beyond the common grocery store types. As mentioned on page 2, varieties like Okinawan, Murasaki, Hannah, Satsuma-imo, and others come in colors ranging from white and orange to deep purple and pink. Their flavors vary from creamy and sweet to nutty and earthy.
Sweet potatoes are also incredibly versatile in cooking. While many people think only of sweet potato pie or casserole, they work just as well in savory meals. Roasted cubes, crispy fries, or baked and topped with black beans and salsa make satisfying everyday dishes.
When Are Sweet Potatoes Ready to Harvest?
Many guides suggest waiting until the vines turn yellow or begin dying back. That advice works in some climates. However, as explained on page 2, in warmer regions vines may remain green and vigorous until the first frost, which is too late for ideal harvest size.
Instead, it is better to follow the maturity date listed by the seed or slip supplier. Mark the planting date on your calendar and count forward to the expected harvest window, as described on page 3.
If the season included extreme heat or drought, it may help to wait for a short period of cooler weather and moderate rainfall before harvesting. However, delaying harvest carries some risk. Tubers can grow very large or overly mature, as shown humorously in the photo on page 3 comparing tiny and oversized sweet potatoes.
What to Do With All the Vines and Leaves
By early fall, sweet potato beds often become dense carpets of vines, as seen in the photo on page 4. These leaves are fully edible and nutritious.
You have several options:
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Eat them. The leaves have a slightly bitter taste and are often sautéed or lightly steamed to mellow the flavor. They can also be blended into smoothies.
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Compost them. They provide excellent “green” material for compost piles.
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Let wildlife enjoy them. As described on page 4, deer love sweet potato leaves. Removing fencing a week before harvest allows them to strip the vines clean, making crowns easier to locate.
Ideal Conditions for Harvest
Page 5 outlines the best harvesting conditions:
• Choose a cloudy or overcast day if possible.
• Move harvested tubers quickly into shade to prevent sunscald.
• Avoid harvesting in muddy soil after heavy rain.
• Avoid extremely dry, rock-hard soil.
The best condition is slightly damp, loose soil that crumbles easily in your hands.
Important Growth Detail Before Digging
A common misunderstanding, explained on page 6, is that sweet potatoes only form at the crown of the plant. In reality, vines can root at nodes along their length and produce additional clusters underground.
This means each plant may produce:
• One large primary cluster at the crown
• Smaller satellite clusters along rooted vines
Each cluster consists of multiple tubers growing from the root system, as shown in the photo of Beauregard clusters on page 7.
Harvesting Strategy
Many gardeners make the mistake of pulling up all the vines at once. As explained on page 7, this can tear vines away from satellite clusters, making them difficult to find later.
Two better approaches:
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Remove vines and thoroughly turn over the entire bed to locate every cluster.
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Start at the vine tips and gently tug to find spots where vines have rooted, then carefully dig around those areas before moving toward the crown.
Harvesting can take time. It is better to work slowly than to leave tubers behind.
Tools for Harvesting
Sweet potatoes often grow deep in the soil, as noted on page 8.
Common tools include:
• Spading fork
• Spade shovel
• Hand shovel
A hand shovel allows careful layer-by-layer digging to reduce damage. Even experienced gardeners occasionally nick a tuber, as shown humorously in the “Oopsie!” image on page 8.
Finding the Crown
The crown is the thick central stem that enters the soil. It differs from the thin vines trailing along the surface.
The image on page 9 shows two crowns, one still in the ground and one lifted out. Locate and mark crowns before removing vines to avoid losing the main cluster.
Digging Up the Tubers
Begin digging in a wide circle around where you expect the cluster to be. As mentioned on page 10, some guesswork is involved, so starting wide reduces accidental damage.
Once you uncover a tuber, carefully loosen soil around the entire cluster before gently lifting it. Separate tubers from vines and brush off loose soil. Do not wash them. Snap off small roots and move them to a curing area.
Why Curing Is Essential
Curing allows sweet potatoes to:
• Heal small cuts and bruises
• Thicken their skins
• Convert starches into sugars
• Improve flavor
• Extend storage life
According to page 11, ideal curing conditions include high humidity and temperatures in the 80s°F. This process typically lasts 1 to 2 weeks.
Options include:
• Garage curing during warm fall weather
• Greenhouse curing
• Storing in ventilated plastic bags kept in a warm location
How to Store Sweet Potatoes
After curing, store tubers in:
• A cool, dry, well-ventilated area
• Temperatures between 50–60°F (page 11) or 55–60°F (page 13)
Avoid refrigeration.
Properly stored sweet potatoes can last for several months.
Frequently Asked Questions
What if I harvest in wet conditions?
Let potatoes dry thoroughly before storage. Do not wash them.
Can I eat sweet potatoes immediately?
Yes, but they taste sweeter after curing.
What if they sprout?
Small sprouts can be removed and the potato eaten. Large sprouts may signal aging.
How do I know if one is bad?
Soft, mushy texture and sour smell indicate spoilage (page 13).
What happens if I leave them too long?
Overmature tubers may crack, become fibrous, or grow excessively large (page 11).
Sweet potatoes are hidden treasures beneath a blanket of vines. With careful timing, gentle digging, and proper curing, you can enjoy your harvest well into winter.
Happy harvesting.
