Organic gardening is becoming increasingly popular as people become more conscious of the food they consume. One of the most popular vegetables to grow organically are potatoes. Potatoes are relatively easy to grow, and they are a staple in many households. Growing organic potatoes is not only good for the environment, but also good for your health as you know exactly what was used to grow them.
The biggest challenge to growing potatoes organically is knowing what kind of organic fertilizer to use and how to cope with weeds and diseases without relying on chemical sprays.
Choosing the Right Seed Potatoes
Choosing the right seed potatoes is a crucial step in growing organic potatoes. The right variety will depend on the type of soil you have, the climate in your area, and the intended use of the potatoes. Here are some tips to help you choose the right seed potatoes:
- Choose certified seed potatoes from a reputable source to ensure that they are disease-free.
- Choose potatoes that are suited to your climate. Some varieties are better suited to cooler climates, while others thrive in warmer temperatures.
- Consider the intended use of the potatoes. Some varieties are better for baking, while others are better for boiling or frying.
- Choose potatoes that are known to have high disease resistance and grow well using organic methods.
It is important to note that seed potatoes are not the same as the potatoes you buy at the grocery store. Grocery store potatoes may be treated with chemicals to prevent sprouting, which can affect their ability to grow. It is best to use certified seed potatoes from a reputable source to ensure the best results.
Once you have chosen your seed potatoes, it is good practice to encourage small buds to grow on them, this will give them a headstart on growing, allowing you to harvest earlier. Before planting very large seed potatoes can be cut into smaller pieces that are at least 2 inches in size, making sure that each piece has at least one “eye” or sprout. Allow the cut potatoes to dry for a day or two before planting to reduce the risk of rot.
Preparing the Soil
Testing the Soil pH
Before planting potatoes, it is important to test the soil pH. Potatoes prefer slightly acidic soil with a pH between 5.0 and 6.0. If the soil pH is too low, add lime to raise it. If the soil pH is too high, add sulfur to lower it. A pH testing kit can be purchased at a garden center or online.
Is sulfur organic?
Sulfur is considered an organic mineral element, but it depends on the context in which it is used.
When sulfur is mined from underground deposits and refined, it is considered an inorganic substance. However, when sulfur is naturally occurring and part of living organisms, it is considered organic. For example, organic sulfur compounds such as cysteine and methionine are essential amino acids found in proteins.
In agriculture, sulfur is often used as an organic pesticide and fungicide in the form of sulfur dust or sprays. It is considered an organic material under USDA’s National Organic Program (NOP) regulations because it is allowed for use in organic farming and is naturally occurring. However, synthetic forms of sulfur that are manufactured for commercial use are not considered organic.
Therefore, whether or not sulfur is considered organic depends on the context in which it is used and the definition of “organic” being used.
Is lime organic?
Lime can be considered organic or inorganic depending on how it is produced and used.
Lime is often used in gardening to adjust soil pH and provide calcium and magnesium nutrients to plants. When lime is produced from naturally occurring sources such as limestone or chalk and is minimally processed, it is considered organic. This type of lime is known as agricultural lime or “aglime” and is allowed for use in organic farming according to USDA’s National Organic Program (NOP) regulations.
On the other hand, lime that is produced using synthetic methods or that has additives is considered inorganic and not allowed in organic farming. This type of lime is often used for industrial purposes such as in construction or water treatment.
Therefore, if you are using agricultural lime that is derived from natural sources and meets NOP regulations, it can be considered organic for gardening purposes. It’s important to read the label and verify that the product is certified organic if you are looking for an organic gardening solution.
Amending the Soil
One of the best ways to prepare the soil for potatoes is to add organic matter. This can be done by planting a cover crop or adding well-rotted compost to the soil two months before planting. Cover crops or “green manures” greatly improve the soil’s tilth, which is the ability of the soil to support plant growth. They also help to suppress weeds and improve soil fertility.
How much farmyard manure should I add to the soil to grow organic potatoes?
The amount of farmyard manure to add to the soil when growing organic potatoes will depend on various factors, including the soil type, the amount of organic matter already present in the soil, and the overall health of the soil.
As a general rule of thumb, it is recommended to add about 4-6 inches (10-15 cm) of well-rotted farmyard manure to the soil before planting potatoes. This will help improve soil structure and fertility by adding organic matter, which will promote healthy root growth and help retain moisture in the soil.
The N-P-K ratio of well-rotted farmyard manure is roughly 1-2-2 and compost is around 2-2-1
However, it’s important to remember that adding too much manure to the soil can lead to nutrient imbalances and potential problems such as nitrogen burn, which can damage or even kill plants. Therefore, it’s best to err on the side of caution and avoid over-applying manure.
Before adding manure to your soil, it’s a good idea to have your soil tested to determine its nutrient content and pH level. This will help you determine how much manure is needed to meet the needs of your plants without causing harm to them.
Overall, adding farmyard manure can be a great way to improve soil fertility and grow healthy organic potatoes, but it’s important to apply it in moderation and consider other factors such as soil type and nutrient content.
The key to getting as much nutrition into the soil without causing damage to the seed potatoes is to apply the farmyard manure as well-rotted as possible and apply it to the soil at the end of the previous growing season. It should be thoroughly well mixed into the soil when you apply it and then mixed again just before planting. I strongly recommend you use a powered tiller or cultivator to help you fully incorporate the organic fertilizer – whether it’s well-rotted farmyard manure or an organic compost high in P and K. Using a spade or a fork won’t break it up or mix it as well as a powered tiller will.
It is also important to ensure that the soil is well-draining. Potatoes do not like to be in waterlogged soil and will rot if they are. If the soil is heavy, add sand or perlite to improve drainage.
Finally, it is important to loosen the soil so that the roots can get good aeration, food, and irrigation. Place the seed potato on top of the soil and cover it with 4 to 6 inches of soil. As the plant grows, “hill” the soil by adding more on top. Hilling ensures that the tubers stay underground and protects them from sunlight, which can cause them to turn green and become toxic.
Caring for your potato plants
Watering your potato plants is essential for their growth and development. However, overwatering can lead to root rot, so it’s important to find the right balance. Water your plants deeply once a week, ensuring that the soil is moist but not waterlogged. In hot weather, you may need to water your potato plants more frequently to prevent the soil from drying out.
After you have planted your potatoes using well-rotted farmyard manure or organic compost, you may want to apply more organic fertilizer as the plants grow about 1 foot tall. This top dressing of organic fertilizer can be applied onto the top and side of the rows/drills of potatoes. Be careful not to add too much – 1 inch onto the soil will be enough.
Hilling is the process of covering the base of the potato plant with soil to encourage the growth of more tubers. Start hilling your plants when they reach a height of about 6 inches. Use a hoe or rake to mound soil around the base of the plant, leaving only the top few leaves exposed. Repeat this process every few weeks until the plants are fully grown. Hilling also helps to prevent sunburn on the potatoes and keeps them from turning green.
Pests and diseases
Organic potato farming can be challenging when it comes to pest and disease management since synthetic pesticides and fungicides are not used. However, there are several effective ways to cope with pest and disease issues in organic potato farming. Here are some strategies to consider:
- Crop rotation: Rotating potato crops with other non-related crops can help break pest and disease cycles. This prevents soil-borne pathogens and pests from building up in the soil over time, reducing the risk of plant disease.
- Companion planting: Planting companion crops that attract beneficial insects or have natural pest-repelling properties can help deter pests and diseases. Examples of beneficial companion plants for potatoes include marigolds, nasturtiums, and borage.
- Biological control: Biological control involves using natural predators or parasites to control pest populations. This can include releasing beneficial insects like ladybugs or lacewings into the field or using nematodes to control soil-borne pests.
- Integrated pest management (IPM): IPM involves using a combination of cultural, biological, and physical controls to manage pest and disease populations. This can include techniques such as trapping pests, using insecticidal soap or horticultural oils, and introducing beneficial insects.
- Disease-resistant potato varieties: Choosing potato varieties that are resistant to common diseases can help reduce the need for chemical fungicides. Examples of disease-resistant potato varieties include Kennebec and Red Norland.
- Good cultural practices: Maintaining healthy soil, proper crop nutrition, and good watering practices can help prevent stress on potato plants, making them less susceptible to disease and pest issues.
- Handpicking: Handpicking pests off potato plants can be an effective way to control pest populations in small-scale farming systems.
Overall, managing pests and diseases in organic potato farming requires a holistic approach that takes into account both natural and cultural controls. By implementing a combination of these strategies, organic farmers can successfully cope with pest and disease challenges while growing healthy, high-quality potato crops.
Harvesting your potatoes
Harvesting your potatoes is the final step in the growing process. Here are some tips to help you harvest your potatoes:
- Harvest your potatoes when the foliage has died back. This is usually around 2-4 weeks after the plants have flowered.
- Use a digging fork to gently lift the potatoes out of the soil. Start at the outer edge of the hill or trench and work your way in.
- Be careful not to damage the potatoes while digging them up. Damaged potatoes will not store.
- After harvesting, allow the potatoes to dry in a well-ventilated shed away from direct light. This will help them cure and develop a tougher skin, which will help them store better.
- Store your potatoes in a cool, dark, and dry place. Do not store them in the refrigerator as this can cause them to become sweet and change their taste and texture.
To summarize, the biggest challenge to growing organic potatoes is fertilizing and pest and disease control. Due to the nature of organic substances, it is more difficult to quantify the amounts needed to perform a certain task, but that does not mean it is impossible. The benefits of growing potatoes organically become apparent when you taste them.