How to Grow Okinawan Sweet Potatoes: From Slips to Potatoes

Are you ready to grow the vibrant purple Okinawan sweet potato in your own garden? Whether you’ve seen them in your local market or heard about their incredible health benefits, these sweet potatoes are not only delicious but also packed with nutrients. Growing them might seem like a challenge, especially if you’ve never tried your hand at root vegetables before. But don’t worry – I’m here to guide you through the entire process, from selecting the right slips to harvesting those beautiful purple potatoes.

Let’s dive into the wonderful world of Okinawan sweet potatoes and discover how you can grow them in your garden.

What Makes Okinawan Sweet Potatoes Special?

Okinawan sweet potatoes are far from ordinary. With their creamy, beige skin and stunning purple-magenta flesh, they stand out from the usual orange-fleshed varieties, offering both beauty and a unique, delicious flavor.

Okinawan sweet potatoes originally came from Central America but were introduced to Japan in the 17th century, becoming a staple in the Okinawan diet. They are well-known for their naturally sweet flavor and are packed with antioxidants, vitamins, and minerals that benefit overall health. In particular, they are rich in anthocyanins, the compounds responsible for their deep purple color and powerful health benefits.

Although commonly associated with Okinawa, these sweet potatoes are also widely grown in Hawaii, where they are sometimes referred to as Hawaiian Sweet Potato. However, it’s important to distinguish them from purple yam (Dioscorea alata), which is a completely different species.

But what’s even better is that they’re relatively easy to grow, once you understand the basics. They thrive in warm climates, making them a perfect addition to gardens in places like Hawaii, California, and the southern U.S.

Step 1: Choose the Right Slips for Planting Okinawan Sweet Potatoes

What are slips?

Slips are young shoots that sprout from a sweet potato and are what you’ll plant to grow your crop. You can either buy slips from a reputable nursery or start your own by sprouting your own Okinawan sweet potatoes. Starting with high-quality slips will give your crop the best start.

Where to find Okinawan sweet potato slips?

If you’re looking for the best slips, I highly recommend searching for organic Okinawan sweet potatoes or slips specifically grown for gardening. You can often find them in local nurseries, online gardening shops, or even specialty markets that sell Hawaiian or Okinawan products.

Step 2: Prepare Your Garden Soil for Okinawan Sweet Potatoes

Okinawan sweet potatoes are a bit picky when it comes to soil. Here’s what you need to know:

• Soil Type: These potatoes prefer loose, well-draining soil. Sandy loam is ideal, as it allows the roots to spread and grow without becoming waterlogged.

• Soil pH: Sweet potatoes grow best in slightly acidic to neutral soil, with a pH range of 5.5 to 6.5. If you’re not sure about your soil’s pH, get it tested before planting.

• Fertilization: Okinawan sweet potatoes don’t require a lot of fertilizers, but adding compost or organic matter to your soil can give them the nutrients they need for healthy growth.

If you’re gardening in a raised bed or container, make sure it has plenty of drainage holes. Sweet potatoes do not like “wet feet” and need a place where water can easily escape.

Step 3: Planting Your Slips

Now that your garden bed or containers are ready, it’s time to plant your Okinawan sweet potato slips! Follow these steps for the best results:

• When to Plant: Okinawan sweet potatoes thrive in warm weather, so plant your slips after the last frost when soil temperatures reach at least 65°F (18°C). In most regions, this means spring to early summer. They need a long frost-free growing season of around 90-150 days.

• Spacing: Plant each slip 12-18 inches apart to give the vines enough room to spread and prevent overcrowding.

• Depth: Bury the slip just enough to cover the roots, leaving the leafy top above the soil. This encourages strong root development and healthy vine growth.

• Watering: Water thoroughly after planting, but avoid overwatering. Okinawan sweet potatoes thrive with moderate moisture and dislike soggy soil.

Tip: If you’re gardening in a cooler climate, consider using black plastic mulch to retain warmth in the soil, helping your sweet potatoes establish more quickly.

Step 4: Care and Maintenance of Okinawan Sweet Potatoes

Okinawan sweet potatoes are low-maintenance plants, but they still need some attention to grow successfully:

• Watering: Keep the soil moist, especially during dry spells, but avoid making it soggy. Too much water can lead to root rot, which is a common issue with sweet potatoes.

• Weeding: Make sure to keep the area around your plants free of weeds, as they can steal nutrients and space from your sweet potatoes.

• Vine Care: These sweet potatoes have long, sprawling vines, so ensure they have enough space to spread. If needed, you can prune the vines to keep them manageable, but avoid excessive pruning, as the leaves help fuel root growth.

Tip: As your plants grow, you’ll see small white flowers bloom on the vines. While the flowers are pretty, they aren’t necessary for the growth of your sweet potatoes, so don’t be concerned if they don’t appear right away.

Step 5: Harvesting Okinawan Sweet Potatoes

So, how do you know when your Okinawan sweet potatoes are ready to harvest? Timing is crucial to getting a good crop.

Signs Your Sweet Potatoes are Ready:

• Leaves: When the leaves of the plant begin to yellow and die back, it’s a clear sign that the sweet potatoes are maturing.

• Time: Okinawan sweet potatoes typically take around 90-120 days to mature, depending on the climate and growing conditions.

• Size: If you’re not sure, you can gently dig around the base of one plant to check the size of the potatoes.

Harvesting Tips:

• Gently dig up your sweet potatoes using a garden fork or spade. Be careful not to damage the delicate tubers.

• After harvesting, allow the potatoes to cure for a few days in a warm, dry place. This helps to enhance their flavor and extend their shelf life.

Step 6: Curing Your Okinawan Sweet Potatoes

Before storing, Okinawan sweet potatoes need to be cured to enhance their sweetness and extend shelf life. Here’s how:

• Timing: Cure freshly harvested sweet potatoes for 7-10 days before storage.

• Conditions: Keep them in a warm (80-85°F / 27-29°C), humid (85-90% humidity) space. A well-ventilated area, like a covered porch, greenhouse, or warm garage, works well.

• Why Cure? Curing helps convert starches into natural sugars, giving them a better flavor. It also toughens the skin, preventing spoilage during storage.

Tip: If you don’t have a humid space, place the sweet potatoes in a box with a damp towel to increase humidity.

Step 7: Storing and Using Okinawan Sweet Potatoes

Once harvested, you’ll want to store your Okinawan sweet potatoes properly to ensure they last. Here’s how:

• Storage: Store your cured sweet potatoes in a cool, dark place with good airflow. A root cellar, pantry, or basement works great.

• Use: Okinawan sweet potatoes are perfect for roasting, mashing, or using in various dishes like soups, stews, and even desserts.

FAQs About Growing Okinawan Sweet Potatoes

1. Can Okinawan sweet potatoes be grown in cold climates? While Okinawan sweet potatoes prefer warm climates, you can still grow them in cooler areas by starting them indoors or using a greenhouse to maintain a consistent temperature.

2. How long does it take to grow Okinawan sweet potatoes? Typically, it takes about 90-120 days from planting to harvesting, depending on the climate.

3. How do I prevent pests from damaging my Okinawan sweet potatoes? Common pests include aphids and sweet potato weevils. Use organic pest control methods like neem oil or insecticidal soap to keep them at bay.

4. Can I grow Okinawan sweet potatoes in containers? Yes, Okinawan sweet potatoes can be grown in containers, as long as the container is large enough and has good drainage.

Conclusion

Growing Okinawan sweet potatoes is a rewarding experience that doesn’t require expert-level gardening skills. With the right conditions, care, and attention, you’ll be enjoying these delicious, nutrient-packed potatoes in no time. Whether you’re growing them in the backyard or in containers, following the steps outlined in this guide will help you achieve a bountiful harvest.

Are you ready to start growing your own Okinawan sweet potatoes? Grab some slips, prepare your garden, and enjoy the journey of bringing this delicious root vegetable to your table!