What Do Potato Plants Look Like When Ready to Harvest?
Potato plants are ready to harvest when the foliage has completely died back, signaling the tubers have matured and their skins have thickened, providing protection during storage. At this stage, no more energy is being directed towards the plant’s top growth.
Understanding the Potato Plant Lifecycle
Potatoes, a staple in diets worldwide, offer a rewarding gardening experience. However, knowing when to harvest them is crucial for achieving the best yield and flavor. The potato plant’s life cycle is a key indicator, with changes in the foliage providing valuable clues about the tuber maturity underground.
The Foliage as an Indicator
The most reliable sign that potatoes are ready to harvest is the condition of the plant’s foliage, or the green leafy growth above ground. As the potatoes mature, the plant naturally begins to shut down, diverting its energy reserves to the tubers.
- Green and Vigorous: The plant is still actively growing, and the potatoes are not yet mature. Harvesting at this stage will result in smaller, less flavorful potatoes with thin skins.
- Yellowing and Browning: The leaves begin to turn yellow and brown as the plant nears the end of its life cycle. This is a good sign that the potatoes are maturing.
- Completely Died Back: The foliage is completely brown and dry. At this stage, the potatoes are fully mature and their skins have thickened, making them ideal for harvesting and long-term storage.
The “Test Dig” Method
Even with foliage die-back as an indicator, it’s a good idea to perform a “test dig” to confirm the maturity of the potatoes.
- Carefully dig around the base of one or two plants, avoiding damaging the tubers.
- Check the size and skin of the potatoes.
- If the potatoes are the desired size and the skins are thick and don’t rub off easily, the rest of the crop is likely ready for harvest. If the skins are thin, wait another week or two.
Varieties and Their Maturity Times
Different potato varieties have different maturity times. Early varieties mature in about 70-80 days, mid-season varieties in 90-100 days, and late-season varieties in 120 days or more. Knowing which variety you planted will help you estimate the harvest time. Here’s a general guideline:
| Potato Variety Type | Days to Maturity | Characteristics |
|---|---|---|
| Early | 70-80 | Smaller, thin skins, not for long storage |
| Mid-Season | 90-100 | Medium size, good for general use |
| Late | 120+ | Larger, thick skins, excellent for storage |
Harvesting Techniques for Optimal Storage
Once the foliage has died back, you’ll want to harvest and store your potatoes properly.
- Choose a dry day to harvest your potatoes.
- Use a garden fork or spade to carefully lift the potatoes from the ground, being careful not to damage them.
- Gently brush off any excess soil, but do not wash them.
- Cure the potatoes for about a week in a cool, dark, and well-ventilated area. This allows the skins to harden further, improving their storage life.
- Store the cured potatoes in a cool, dark, and humid environment (ideally 40-50°F).
Common Mistakes to Avoid
Several mistakes can lead to a poor potato harvest or storage.
- Harvesting too early: Harvesting before the potatoes are mature results in smaller potatoes with thin skins that don’t store well.
- Damaging the potatoes during harvest: Damaged potatoes are more susceptible to rot.
- Washing potatoes before storing: Washing removes the protective layer of soil and increases the risk of rot.
- Storing potatoes in a warm or humid environment: This promotes sprouting and decay.
Frequently Asked Questions (FAQs)
#### Can I harvest potatoes while the plant is still green?
While you can harvest potatoes while the plant is still green (often called “new potatoes”), they will be smaller, have thinner skins, and will not store well. They are best eaten soon after harvesting.
#### What happens if I leave the potatoes in the ground too long?
Leaving the potatoes in the ground too long can make them susceptible to pests and diseases, such as wireworms and potato blight. They may also start to sprout, which reduces their quality.
#### Is it okay to harvest potatoes after a frost?
If the foliage has been killed by frost, it’s best to harvest the potatoes as soon as possible. The frost can damage the potatoes if they remain in the ground for an extended period.
#### How do I know if my potatoes have a disease?
Signs of potato disease include lesions on the tubers, discoloration, and a foul odor. If you suspect your potatoes have a disease, discard them and do not plant potatoes in the same location next year.
#### Can I eat potatoes that have sprouted?
Yes, you can eat potatoes that have sprouted, but you should remove the sprouts first. The sprouts contain solanine, a toxic alkaloid. The potato itself is generally safe to eat as long as it is firm and not green.
#### How long can I store potatoes?
Properly stored potatoes can last for several months in a cool, dark, and humid environment. Check them periodically for signs of spoilage.
#### What is the best temperature for storing potatoes?
The ideal storage temperature for potatoes is 40-50°F (4-10°C). This prevents sprouting and decay.
#### Can I store potatoes in the refrigerator?
Storing potatoes in the refrigerator can cause them to become sweet due to the conversion of starch to sugar. If you must refrigerate them, use them quickly.
#### What causes potatoes to turn green?
Potatoes turn green when they are exposed to light. This is due to the production of chlorophyll and solanine. Green potatoes should be peeled deeply to remove the green areas before eating.
#### Why are my potatoes small?
Small potatoes can be caused by poor soil, lack of water, insufficient sunlight, or harvesting too early. Ensure your soil is rich in nutrients, water regularly, and plant in a sunny location.
#### Can I plant the small potatoes from my harvest?
You can plant small potatoes (seed potatoes) from your harvest, but it is generally recommended to purchase certified seed potatoes from a reputable supplier. This will help ensure that your potatoes are free from disease.
#### How do I prevent pests and diseases in my potato crop?
To prevent pests and diseases, choose disease-resistant varieties, practice crop rotation, maintain good soil health, and control weeds. Regularly inspect your plants for signs of pests or diseases and take appropriate action if necessary.