Sweet potatoes, with their vibrant orange flesh and naturally sweet flavor, are a versatile and nutritious addition to any garden. Unlike regular potatoes, which are grown from seed potatoes (actual potatoes), sweet potatoes are propagated from slips. But what exactly are slips, and how do you grow them? This guide provides a detailed, step-by-step explanation of how to start sweet potatoes, ensuring a bountiful harvest.
Understanding Sweet Potato Slips
Sweet potatoes don’t produce seeds readily in most climates, making slips the preferred method of propagation. Slips are essentially sprouts that emerge from the sweet potato itself. These sprouts develop roots and leaves and are then transplanted into the garden to grow into mature sweet potato plants. The process of growing slips is surprisingly straightforward and can be started indoors well before the last frost, giving you a head start on the growing season. Starting your own slips is cost-effective and allows you to choose the specific sweet potato varieties you want to grow.
Preparing to Grow Sweet Potato Slips
Before diving into the sprouting process, it’s crucial to gather the necessary supplies and prepare your sweet potatoes. This initial preparation sets the stage for successful slip production.
Choosing the Right Sweet Potatoes
The foundation of a successful sweet potato crop lies in selecting healthy and disease-free parent sweet potatoes for sprouting. Opt for organically grown sweet potatoes, as conventionally grown ones may be treated with sprout inhibitors. Look for firm, unblemished potatoes without any signs of rot or soft spots. The size of the potato isn’t as crucial as its overall health; medium to large potatoes generally work well.
Consider the variety you want to grow. Sweet potatoes come in various colors and flavors, from the classic orange Beauregard to the purple-skinned Okinawan. Ensure you select a variety suited to your local climate and growing conditions. If you’ve grown sweet potatoes before and had success with a particular variety, using one of those is a safe bet.
Gathering Essential Supplies
To successfully sprout sweet potato slips, you’ll need a few basic supplies. These include:
- Sweet potatoes (as mentioned above)
- A clean glass jar or container (wide-mouthed jars work best)
- Toothpicks or skewers
- Water (tap water is fine, but let it sit for 24 hours to allow chlorine to dissipate)
- Potting mix or seed starting mix
- Small pots or containers for transplanting slips
- A warm, well-lit location
Having all these materials readily available will streamline the sprouting process and ensure you’re prepared for each step.
Sprouting Sweet Potatoes: Two Proven Methods
There are two main methods for sprouting sweet potatoes: the water method and the soil method. Both are effective, but they offer slightly different advantages.
The Water Method
The water method is a popular and visually appealing way to sprout sweet potatoes. It allows you to easily monitor root and sprout development.
To begin, thoroughly clean the sweet potato to remove any dirt or debris. Insert toothpicks or skewers around the middle of the potato, spacing them evenly. These will act as supports, allowing you to suspend the potato in the jar.
Fill the jar with water, ensuring that the bottom third to half of the sweet potato is submerged. The top portion should remain dry. Place the jar in a warm, well-lit location, but avoid direct sunlight, which can overheat the water.
Change the water every few days to prevent the growth of bacteria and mold. Within a few weeks, you should start to see sprouts emerging from the sweet potato. Roots will also begin to develop from the submerged portion.
Once the sprouts reach about 6-8 inches in length, they are ready to be carefully removed from the sweet potato. Gently twist or snap them off, trying to retain as many roots as possible. Place the removed slips in a glass of water to encourage further root development before planting.
The Soil Method
The soil method involves burying the sweet potato in moist potting mix. This method tends to produce a higher yield of slips but makes it slightly harder to monitor the sprouting progress.
Fill a container with moist potting mix or seed starting mix. The container should be large enough to accommodate the entire sweet potato. Bury the sweet potato horizontally in the soil, leaving the top inch or two exposed.
Place the container in a warm, well-lit location and keep the soil consistently moist but not waterlogged. Water whenever the top inch of soil feels dry.
Within a few weeks, sprouts will begin to emerge from the soil. As with the water method, wait until the sprouts reach about 6-8 inches in length before harvesting them.
To harvest, gently dig around the base of the sprout and carefully cut it away from the sweet potato, trying to retain as many roots as possible. As with the water method, place the removed slips in a glass of water to encourage further root development.
Nurturing Your Sweet Potato Slips
Once you’ve harvested your slips, proper care is essential to ensure they thrive before transplanting them into the garden. This involves encouraging root growth and hardening them off to acclimate them to outdoor conditions.
Encouraging Root Development
After removing the slips from the parent sweet potato, place them in a glass or jar filled with water. Ensure that the roots are submerged, but the leaves remain above the water line. This will encourage further root development.
Change the water every few days to prevent the growth of bacteria and algae. Within a week or two, the slips should develop a more robust root system, making them ready for planting.
Adding a diluted liquid fertilizer to the water can further promote root growth. Use a balanced fertilizer, such as a 10-10-10, diluted to half strength.
Hardening Off Your Slips
Before transplanting your sweet potato slips into the garden, it’s crucial to harden them off. This process gradually acclimates the slips to outdoor conditions, reducing the risk of shock and increasing their chances of survival.
Start by placing the slips outdoors in a sheltered location for a few hours each day. Gradually increase the amount of time they spend outdoors, exposing them to more sunlight and wind.
Over the course of a week or two, the slips will become more accustomed to outdoor conditions. Once they can tolerate a full day outdoors without wilting or showing signs of stress, they are ready to be transplanted into the garden.
Transplanting Sweet Potato Slips into the Garden
Transplanting sweet potato slips requires careful planning and execution to ensure optimal growth and yield. This includes selecting the right location, preparing the soil, and planting the slips correctly.
Choosing the Right Location
Sweet potatoes thrive in warm, sunny locations with well-drained soil. Choose a spot in your garden that receives at least 6-8 hours of sunlight per day.
Avoid planting sweet potatoes in areas where the soil is heavy clay or prone to waterlogging. These conditions can lead to root rot and stunted growth.
Sweet potatoes prefer slightly acidic soil with a pH between 5.5 and 6.5. Test your soil before planting and amend it if necessary to achieve the optimal pH range.
Preparing the Soil
Proper soil preparation is essential for healthy sweet potato growth. Start by removing any weeds, rocks, or debris from the planting area.
Amend the soil with compost or well-rotted manure to improve drainage, fertility, and water retention. This will provide the sweet potato plants with the nutrients they need to thrive.
Till or dig the soil to a depth of at least 12 inches to loosen it and improve aeration. This will allow the sweet potato roots to penetrate the soil more easily.
Create raised beds or mounds to further improve drainage and warm the soil more quickly. Raised beds are especially beneficial in areas with heavy clay soil or a short growing season.
Planting the Slips
Plant sweet potato slips after the last frost, when the soil has warmed to at least 60°F (16°C). Space the slips 12-18 inches apart in rows that are 3-4 feet apart.
Dig a small hole for each slip and gently place the roots into the hole. Backfill with soil, making sure to cover the roots completely. Leave only the top few leaves exposed.
Water the newly planted slips thoroughly to help them establish their roots. Mulch around the plants with straw or hay to conserve moisture, suppress weeds, and regulate soil temperature.
Caring for Your Sweet Potato Plants
Once your sweet potato slips are planted, ongoing care is essential to ensure a bountiful harvest. This includes watering, fertilizing, and pest control.
Watering
Water sweet potato plants regularly, especially during dry periods. Aim to keep the soil consistently moist but not waterlogged.
Water deeply and less frequently, rather than shallowly and more often. This encourages the roots to grow deeper into the soil, making the plants more drought-tolerant.
Avoid overhead watering, which can promote the development of fungal diseases. Instead, water at the base of the plants.
Fertilizing
Sweet potatoes are relatively light feeders, but they benefit from regular fertilization. Apply a balanced fertilizer, such as a 10-10-10, every 4-6 weeks.
Avoid over-fertilizing with nitrogen, which can promote excessive vine growth at the expense of root development.
Side-dress the plants with compost or well-rotted manure to provide a slow-release source of nutrients.
Pest and Disease Control
Sweet potatoes are generally resistant to pests and diseases, but they can be susceptible to certain problems. Common pests include sweet potato weevils, flea beetles, and aphids.
Inspect your plants regularly for signs of pest infestation or disease. Handpick pests or use insecticidal soap or neem oil to control them.
Practice crop rotation to prevent the buildup of soilborne diseases. Choose disease-resistant sweet potato varieties whenever possible.
Ensure good air circulation around the plants to reduce the risk of fungal diseases. Avoid overcrowding and prune the vines if necessary.
Harvesting and Curing Sweet Potatoes
Harvesting and curing are the final steps in the sweet potato growing process. Proper timing and curing techniques are essential for maximizing flavor and storage life.
Knowing When to Harvest
Sweet potatoes are typically ready to harvest 90-120 days after planting. The exact timing will depend on the variety and growing conditions.
A good indication that sweet potatoes are ready to harvest is when the foliage begins to turn yellow and die back.
Check the size of the sweet potatoes by carefully digging around the base of a plant. If the potatoes are a desirable size, it’s time to harvest.
Harvest sweet potatoes before the first frost, as exposure to cold temperatures can damage them and reduce their storage life.
Harvesting Techniques
Choose a dry day for harvesting sweet potatoes. Use a garden fork or shovel to carefully dig around the plants, being careful not to damage the potatoes.
Lift the plants from the ground and gently shake off any excess soil. Handle the sweet potatoes with care, as they are easily bruised.
Cure the sweet potatoes immediately after harvesting to improve their flavor and storage life.
Curing Sweet Potatoes
Curing sweet potatoes involves exposing them to warm, humid conditions for a period of 7-10 days. This allows the skins to harden and any minor cuts or bruises to heal.
Place the sweet potatoes in a well-ventilated area with a temperature of 80-85°F (27-29°C) and a humidity level of 85-90%.
You can use a greenhouse, shed, or even a spare room for curing. Place a humidifier or pans of water in the curing area to maintain the desired humidity level.
After curing, store the sweet potatoes in a cool, dark, and dry place with a temperature of 55-60°F (13-16°C). Properly cured and stored sweet potatoes can last for several months.
Growing your own sweet potatoes from slips is a rewarding experience that provides you with a delicious and nutritious harvest. By following these detailed steps, you can successfully start your own sweet potato plants and enjoy the fruits (or rather, roots) of your labor.
What exactly are sweet potato slips, and why are they important for starting sweet potatoes?
Slips are sprouted shoots that grow from a mature sweet potato. They are essentially baby sweet potato plants, ready to be detached and planted directly into the soil. Using slips is the most common and reliable way to propagate sweet potatoes since planting the root itself won’t directly produce more sweet potatoes; instead, it will produce these slips.
Starting with slips gives you a head start on the growing season compared to directly planting seeds, which are less common for sweet potatoes. The slips already have established roots and shoots, allowing them to quickly adapt and thrive in their new environment. This ultimately translates into a higher yield and healthier sweet potato harvest.
How do I grow sweet potato slips from a store-bought sweet potato?
To grow slips, begin by selecting a healthy, organic sweet potato (if possible, to avoid any sprout inhibitors). Place the sweet potato in a container of water, submerging the bottom half. You can use toothpicks to suspend the potato over the water line, or partially bury it in moist potting mix.
Position the container in a warm, sunny location. Within a few weeks, sprouts will begin to emerge from the potato. Once the sprouts, or slips, reach 6-8 inches in length, they are ready to be carefully twisted off the potato. Place the slips in water for a few days to allow them to develop roots before planting them in the ground.
When is the best time to plant sweet potato slips?
The ideal time to plant sweet potato slips is after the last frost when the soil temperature has consistently reached at least 65 degrees Fahrenheit. Sweet potatoes are sensitive to cold and require warm conditions to thrive. Planting too early can result in stunted growth or even death of the slips.
Generally, this falls in late spring or early summer, depending on your specific climate. Check your local weather forecast and historical frost data to determine the optimal planting window for your region. Aim to plant when you are confident that there is no further risk of frost and the soil is sufficiently warm.
What are the ideal soil conditions for growing sweet potatoes?
Sweet potatoes prefer well-drained, sandy loam soil. This type of soil provides good aeration, which is crucial for root development. Heavy clay soil can restrict root growth and lead to misshapen sweet potatoes. If you have clay soil, amend it with organic matter like compost or aged manure to improve drainage and fertility.
The ideal soil pH for sweet potatoes is between 6.0 and 6.5. A slightly acidic soil promotes nutrient uptake. You can test your soil pH using a soil testing kit and adjust it accordingly with lime (to raise the pH) or sulfur (to lower the pH). Ensure the soil is loose and free of rocks and debris to allow for unobstructed root growth.
How far apart should I plant my sweet potato slips?
Sweet potato slips should be planted 12-18 inches apart in rows that are 3-4 feet apart. This spacing allows for adequate vine growth and ample sunlight penetration to the developing sweet potatoes. Overcrowding can lead to reduced yields and increased susceptibility to diseases.
Proper spacing also facilitates easier weeding and harvesting. The wide rows provide enough room to walk between the plants and tend to them throughout the growing season. Remember to consider the specific variety of sweet potato you are growing, as some varieties may have different spacing requirements.
What kind of care do sweet potatoes need during the growing season?
Sweet potatoes require consistent watering, especially during the initial establishment period after planting the slips. Water deeply when the top inch of soil feels dry. Once established, they are relatively drought-tolerant but benefit from regular watering during prolonged dry spells. Avoid overwatering, as this can lead to root rot.
Weed control is also essential for sweet potato growth. Regularly remove weeds around the plants to prevent them from competing for nutrients and water. Mulching with straw or other organic materials can help suppress weed growth and retain soil moisture. Additionally, sweet potatoes benefit from occasional fertilization with a balanced fertilizer, following the package instructions carefully to avoid over-fertilizing.
How do I know when my sweet potatoes are ready to harvest?
Sweet potatoes are typically ready to harvest about 90-120 days after planting, depending on the variety and growing conditions. A good indicator is when the vines start to yellow and die back. However, don’t wait too long, as frost can damage the sweet potatoes and shorten their storage life.
To check for ripeness, carefully dig around a few plants and examine the size of the sweet potatoes. They should be a good size and have a smooth, firm skin. When you are satisfied with the size and maturity, harvest the rest of the crop on a dry day. Use a spading fork to gently lift the sweet potatoes from the soil, being careful not to bruise or damage them.