Cultivating Flora

How to Grow Sweet Potatoes in Alaska

Growing sweet potatoes in Alaska may seem like a daunting task due to the state’s short growing season and cooler climate. However, with the right techniques and a bit of preparation, it is entirely possible to cultivate this nutritious and delicious root vegetable even in the far north. This guide will provide you with essential tips on how to successfully grow sweet potatoes in Alaska.

Understanding Sweet Potatoes

Sweet potatoes (Ipomoea batatas) are warm-season crops that thrive in sunny environments with well-drained soil. Known for their sweet flavor and numerous health benefits, they are a staple in many diets. But how do you adapt their cultivation to the unique conditions of Alaska?

Hardiness Zones

Alaska spans multiple hardiness zones, with most areas falling between zones 2 and 5. Sweet potatoes are typically grown in warmer zones (zones 8-11), which means you’ll need to take extra steps to ensure they flourish in the cooler, shorter growing seasons found in Alaska.

Choosing the Right Variety

Not all sweet potato varieties are suitable for northern climates. When selecting sweet potatoes for your Alaskan garden, look for early-maturing varieties that can produce within a shorter growing window. Here are some varieties you might consider:

Preparing Your Garden

Location

Choose a spot in your garden that receives full sun for at least six hours per day. Sweet potatoes love warmth, so a south-facing slope or a location sheltered from harsh winds can help maximize sunlight exposure.

Soil Preparation

Sweet potatoes require well-drained, sandy loam soil that is rich in organic matter. Heavy clay soil can lead to rot, so amending your soil is essential. Here’s how to prepare your garden bed:

  1. Test Your Soil: Conduct a soil test to determine pH and nutrient levels. Sweet potatoes prefer slightly acidic to neutral soil (pH 5.8 – 6.5).
  2. Amend the Soil: Add organic materials like compost or aged manure to improve drainage and fertility.
  3. Create Raised Beds: If your soil is heavy or not well-draining, consider creating raised beds filled with sandy loam that allows for better drainage and warms up faster in spring.

Starting Sweet Potatoes Indoors

Due to Alaska’s short growing season, starting sweet potatoes indoors is often necessary to give them a head start before transplanting them outside. Here’s how to do it:

Sprouting Slips

  1. Choose Healthy Tubers: Purchase healthy sweet potato tubers from a local nursery or garden center.
  2. Water Method: Submerge half of the sweet potato in water using toothpicks to hold it up in a jar or glass. Place it in a warm location with indirect sunlight.
  3. Slip Growth: After about 4-6 weeks, sprouts (or slips) will begin to emerge from the top of the tuber. When they are about 6-8 inches long, carefully twist them off.
  4. Rooting Slips: Place the slips in water until roots form (approximately another week).

Timing

Start your slips indoors about 6-8 weeks before your last expected frost date (usually around mid-April to late May depending on your region).

Transplanting Outdoors

When nighttime temperatures consistently stay above 50°F (around late May to early June), it’s time to transplant your slips outdoors.

Hardening Off

Before planting them directly into the garden, harden off your young slips by gradually exposing them to outdoor conditions over a week or two. Begin by placing them outside for a few hours each day and slowly increase their exposure time.

Planting

  1. Spacing: Plant slips about 12-18 inches apart in rows that are spaced approximately 3 feet apart.
  2. Planting Depth: Bury the slips up to their leaves; this encourages stronger root development.

Care During the Growing Season

Once planted, maintaining appropriate care is crucial for healthy growth.

Watering

Sweet potatoes need consistent moisture but do not tolerate standing water. Water deeply once a week unless there’s significant rainfall, ensuring moisture penetrates at least 6 inches down into the soil.

Fertilization

Feed your plants with an all-purpose fertilizer at planting time or use organic options like compost tea throughout the growing season. Avoid high nitrogen fertilizers as they can encourage foliage growth at the expense of root development.

Weed Control

Keep the area around your plants weed-free, as weeds compete for nutrients and water. Mulching around the base of the plants can help suppress weeds while retaining moisture.

Monitoring Pests and Diseases

Sweet potatoes can be susceptible to pests such as spider mites and aphids, as well as diseases like root rot if conditions are too moist. Regularly inspect your plants for any signs of trouble:

Harvesting Sweet Potatoes

The timing of your harvest is crucial for optimal sweetness and storage life.

When to Harvest

Generally, sweet potatoes are ready to harvest about 90-120 days after planting when their leaves begin to yellow and die back. The exact timing will depend on the variety chosen and local conditions.

Harvesting Technique

Use a spading fork or shovel to gently lift tubers from the ground, taking care not to bruise them as they are delicate once harvested.

Curing Sweet Potatoes

To enhance flavor and extend storage life, curing sweet potatoes after harvesting is essential:

  1. Cure Location: Place harvested sweet potatoes in a warm (80°F-85°F), humid environment for about two weeks.
  2. Storage Conditions: After curing, store them in a cool (55°F-60°F), dark place with good ventilation.

Conclusion

Growing sweet potatoes in Alaska requires thoughtful planning and adaptation of traditional methods due to unique climatic challenges, but with diligence and care, you’ll be rewarded with a bountiful harvest of this nutritious vegetable by late summer or early fall. By selecting the right varieties, starting indoors, ensuring proper care throughout their growth cycle, and harvesting correctly, you can enjoy delicious homegrown sweet potatoes even under Alaska’s northern skies!