What is Potato Seed? Understanding Seed Potatoes for a Bountiful Harvest
Potato seed, often referred to as seed potatoes, is essentially a piece of potato (usually a small, whole potato or a cut piece) that contains at least one healthy eye or sprout, which is planted to grow a new potato plant. It is not a true seed in the botanical sense, like a tomato seed.
The Misnomer: Why “Seed” Potato?
The term “seed potato” is somewhat misleading. Unlike most crops grown from true seeds derived from flowering, potatoes are usually propagated vegetatively using tubers. This is a form of asexual reproduction. The term persists due to its historical usage and the analogous role it plays in initiating the potato plant’s lifecycle, just as a true seed does for other crops.
Benefits of Using Seed Potatoes
Using certified seed potatoes offers several significant advantages over simply planting leftover potatoes from the grocery store:
- Disease Control: Certified seed potatoes are rigorously tested and guaranteed to be free from common potato diseases like late blight, potato virus Y (PVY), and ring rot.
- Variety Purity: Seed potatoes ensure you’re growing the specific variety you purchased, with consistent characteristics and predictable yields.
- Improved Yields: Certified seed potatoes come from plants that have been carefully selected for their superior vigor and productivity, resulting in healthier plants and higher yields.
- Predictable Growth: Using seed potatoes allows for more predictable and uniform growth patterns, leading to easier management and harvesting.
- Reduced Risk of Pests: Seed potatoes are often treated to prevent certain soil-borne pests from harming the growing plant.
Types of Seed Potatoes
Seed potatoes come in different forms, each with its own advantages:
- Whole Seed Potatoes: Smaller potatoes (typically 1-2 ounces) can be planted whole. This is often recommended for smaller varieties and avoids the risk of disease spreading during cutting.
- Cut Seed Potatoes: Larger potatoes are typically cut into pieces, each containing at least one eye or sprout. Cutting increases the number of seed pieces you get from a single potato.
- Mini-Tubers: These are small, tissue culture-derived potatoes that are grown under controlled conditions. They offer excellent disease resistance and uniformity.
Cutting Seed Potatoes: Best Practices
If you choose to cut your seed potatoes, follow these best practices:
- Choose the Right Potatoes: Select firm, healthy potatoes with well-developed eyes.
- Sterilize Your Knife: Use a sharp, clean knife and sterilize it between cuts to prevent the spread of disease. You can use a solution of 1 part bleach to 9 parts water.
- Cut into Pieces: Each piece should be roughly 1-2 ounces and have at least one, preferably two, healthy eyes.
- Cure the Cut Surfaces: Allow the cut surfaces to “cure” or suberize for a few days in a cool, dry, and well-ventilated place. This helps prevent rot and disease.
Preparing Your Seed Potatoes for Planting: Sprouting and Chitting
Chitting, or pre-sprouting, involves encouraging the development of short, green sprouts on your seed potatoes before planting. This gives the potato plant a head start and can lead to earlier harvests and higher yields.
- Provide Light: Place the seed potatoes in a single layer in a tray or egg carton in a cool (around 50-60°F), bright location. Avoid direct sunlight, which can damage the sprouts.
- Wait for Sprouts: Allow the potatoes to sprout for a few weeks until the sprouts are about 1/2 to 1 inch long.
- Handle Carefully: Handle the sprouted potatoes carefully to avoid damaging the sprouts during planting.
Planting Seed Potatoes: The Basics
Here’s a basic guide to planting seed potatoes:
- Prepare the Soil: Choose a sunny location with well-drained soil. Amend the soil with compost or other organic matter.
- Dig Trenches: Dig trenches about 4-6 inches deep and 2-3 feet apart.
- Plant the Seed Potatoes: Place the seed potatoes (sprouts facing upwards if they have been chitted) in the trenches, spacing them about 12 inches apart.
- Cover with Soil: Cover the seed potatoes with soil.
- Water Regularly: Water the soil regularly, especially during dry periods.
Common Mistakes to Avoid
- Planting Grocery Store Potatoes: These potatoes may be treated to prevent sprouting and may carry diseases. They also may not be true to the variety they appear to be.
- Planting Rotten or Diseased Potatoes: Planting diseased potatoes will only spread the problem to your garden.
- Cutting Potatoes Too Small: If the seed pieces are too small, they may not have enough energy to sprout and grow properly.
- Planting in Poorly Drained Soil: Potatoes need well-drained soil to prevent rot.
- Not Hilling the Plants: Hilling, or mounding soil around the stems of the plants, encourages more potato production.
Table: Comparing Seed Potato Options
| Feature | Whole Seed Potatoes | Cut Seed Potatoes | Mini-Tubers |
|---|---|---|---|
| Cost | Higher per potato | Lower per potato | Highest |
| Disease Risk | Lower | Higher | Lowest |
| Preparation | Minimal | Requires cutting | Minimal |
| Plant Size | Varies by variety | Varies by variety | Typically smaller at first |
| Best For | Small gardens, disease-prone areas | Large gardens, cost-effective | Disease-free starting point, research |
Frequently Asked Questions (FAQs)
Can I use potatoes from the grocery store as seed potatoes?
Generally, it’s not recommended to use grocery store potatoes as seed potatoes. They may be treated with chemicals to prevent sprouting, may carry diseases, and may not be true to type – meaning you won’t necessarily get the potato you expect. Certified seed potatoes are a much safer and more reliable option.
How do I store seed potatoes before planting?
Store seed potatoes in a cool, dark, and well-ventilated place, such as a garage or basement. Ideal temperatures are between 40-50°F (4-10°C). Avoid storing them in direct sunlight or in a warm, humid environment, as this can cause them to sprout prematurely or rot.
How many seed potatoes do I need to plant?
The number of seed potatoes you need depends on the size of your garden and the spacing you use. As a general rule, you’ll need about 1-2 pounds of seed potatoes per 10 feet of row.
What if my seed potatoes sprout too early?
If your seed potatoes sprout too early, try to keep the sprouts short and stocky by providing them with light. If the sprouts become long and spindly, carefully rub them off before planting.
What is “hilling” potatoes, and why is it important?
Hilling involves mounding soil around the stems of the potato plants as they grow. This encourages the plant to produce more tubers along the buried stem, resulting in a higher yield. It also helps to protect the tubers from sunlight, which can cause them to turn green and become toxic.
How deep should I plant seed potatoes?
Plant seed potatoes about 4-6 inches deep. This depth provides enough soil cover to protect the developing tubers and helps to keep the soil moist.
How often should I water my potato plants?
Water potato plants regularly, especially during dry periods. Keep the soil consistently moist, but not waterlogged. Overwatering can lead to rot.
What are some common potato pests and diseases?
Common potato pests include potato beetles, aphids, and wireworms. Common diseases include late blight, early blight, and scab. Use certified seed potatoes to minimize disease risk and consider using organic pest control methods.
When is the best time to harvest potatoes?
The best time to harvest potatoes depends on the variety and your intended use. Early potatoes can be harvested when the plants begin to flower, while maincrop potatoes should be harvested after the foliage has died back.
How do I cure potatoes after harvesting?
Curing potatoes involves drying them in a well-ventilated place for a week or two after harvesting. This helps to toughen the skin and prevent rot during storage.
How should I store potatoes after harvesting?
Store cured potatoes in a cool, dark, and well-ventilated place, such as a root cellar or basement. Ideal storage temperatures are between 40-50°F (4-10°C).
What does “certified seed potato” mean?
“Certified seed potato” means the potatoes have been inspected and certified by a reputable agency to be free from specific diseases and pests. This ensures that you are planting healthy, high-quality seed potatoes.