Can you plant potatoes in summer? - Plant Care Guide

Yes, you can plant potatoes in summer, specifically for a fall or second harvest, but it requires choosing the right variety and managing certain challenges unique to warmer weather. This practice, often called succession planting or a second crop, allows gardeners to extend their potato season, but warm soil temperatures can initially hinder tuber formation.

Why would you plant potatoes in summer?

You would plant potatoes in summer primarily to achieve a second harvest of fresh potatoes in the fall, thereby extending your growing season and maximizing your yield. This strategy is especially appealing for those who want to enjoy the taste of freshly dug potatoes beyond the typical early summer crop. It's about optimizing garden space and production.

Here are the main reasons to consider planting potatoes in summer:

• Extended Harvest (Fall Crop):
  • Succession Planting: Many gardeners plant potatoes in early spring for a summer harvest. By planting potatoes in summer, you can ensure a fresh supply of potatoes for fall and even into early winter (depending on your climate). This extends the window for enjoying homegrown tubers.
  • Freshness: There's nothing quite like the taste of freshly dug potatoes. A fall crop allows you to enjoy this freshness much later in the year, long after your first crop has been harvested and stored.
• Optimal Tuber Formation in Cooler Fall Soil:
  • Temperature Sensitivity: Potato plants form their tubers (the edible part) best when soil temperatures are between 60-70°F (15-21°C). High summer temperatures (above 80°F or 27°C) can inhibit tuber formation, leading to smaller yields or "no-tuber" plants.
  • Fall Advantage: While the initial summer planting might occur in warm soil, the plants grow vegetatively (develop leaves and stems) during the heat. As the days shorten and temperatures cool in late summer and fall, the soil temperatures become ideal for efficient tuber development, leading to potentially excellent yields from your summer-planted crop.
• Utilizing Garden Space:
  • Succession: Summer planting allows you to use garden beds that have become available after an early summer harvest of other crops (like spring greens, peas, or early root vegetables). This is an efficient way to make continuous use of your garden space throughout the season.
  • Maximize Productivity: It helps maximize the overall productivity of your small yard or garden.
• Better Storage for Some Varieties:
  • Cooler Harvest: Potatoes harvested in the fall, when temperatures are naturally cooler, often have better curing and storage potential than those harvested in the heat of summer. This can lead to a longer shelf life for your second crop.
• Pest and Disease Management:
  • Breaking Cycles: For some regions, certain potato pests or diseases (like early blight) might be more prevalent earlier in the season. A later planting can sometimes help you avoid the peak activity of these issues, giving your plants a cleaner start.
  • Varietal Choice: You can choose varieties for your summer planting that are more resistant to specific late-season pests or diseases.
• Variety Selection:
  • Some potato varieties are better suited for summer planting as they are either more heat-tolerant or have a shorter maturity time, allowing them to produce tubers before severe frost.

In essence, planting potatoes in summer is a smart strategy for gardeners who want to extend their harvest, optimize their garden space, and take advantage of cooler fall soil temperatures for excellent tuber development.

What challenges do summer-planted potatoes face?

Summer-planted potatoes face several challenges primarily due to the hot summer temperatures, which can negatively impact tuber formation and increase vulnerability to pests and diseases. Gardeners who opt for a second potato crop must be prepared to mitigate these specific issues to ensure a successful harvest.

Here are the main challenges that summer-planted potatoes might encounter:

1. High Soil Temperatures (Primary Challenge):
   • Inhibition of Tuber Set: Potato plants are cool-season crops. Tuber formation is significantly inhibited when soil temperatures rise above 80°F (27°C). If the soil remains too hot during the critical tuber initiation phase, plants may grow lush foliage but produce very few or no tubers. This is often called "heat dormancy" for tuberization.
   • Plant Stress: High temperatures stress the plants overall, leading to reduced vigor and making them more susceptible to other problems.
   • Result: Reduced yields or complete crop failure if not managed.
2. Increased Watering Needs:
   • Evaporation: Hot summer sun and dry air lead to rapid evaporation of moisture from the soil.
   • Transpiration: Plants lose water more quickly through their leaves (transpiration) in hot weather.
   • Result: Summer-planted potatoes will require more frequent and consistent watering compared to a spring crop to prevent stress and ensure continuous growth. Inconsistent watering can lead to issues like hollow heart or secondary growth.
3. Pest Pressure:
   • Peak Season: Summer is often the peak season for many garden pests.
   • Common Pests: Colorado potato beetles, flea beetles, aphids, and potato leafhoppers can be particularly problematic, weakening plants and potentially transmitting diseases.
   • Result: Requires diligent monitoring and proactive pest management.
4. Disease Pressure:
   • Fungal Diseases: Warm, humid summer conditions can be ideal for the development and spread of several fungal diseases, such as early blight or late blight. These can quickly defoliate plants, especially if they are already stressed.
   • Bacterial Diseases: Bacterial wilt can also be an issue in hot, wet conditions.
   • Result: Increased vigilance for disease symptoms and timely treatment are essential.
5. Availability of Seed Potatoes:
   • Seasonal Supply: Finding high-quality, certified seed potatoes for summer planting can be a challenge. Most garden centers stock seed potatoes in early spring. By summer, supplies may be limited or of lower quality.
   • Alternative: Chitted Store-Bought: While possible, using grocery store potatoes carries disease risks.
   • "Second Crop" Seed Potatoes: Some suppliers offer "second crop" seed potatoes in late spring/early summer that are specifically for later planting.
6. Shorter Growing Season (Late Summer/Early Fall):
   • Frost Risk: Depending on your climate, summer-planted potatoes need enough time to grow and set tubers before the first hard frost. Choosing shorter-season varieties is crucial.
   • Result: Requires careful timing and selection of maturity dates.
7. Competition from Weeds:
   • Vigorous Weeds: Summer also sees vigorous weed growth. Weeds compete with potatoes for water, nutrients, and sunlight, which are already limited resources in hot, dry conditions.
   • Result: Requires consistent weeding or good mulching.

Despite these challenges, with proper planning, variety selection, and attentive care, planting potatoes in summer for a fall harvest can be a rewarding endeavor.

What are the best potato varieties for summer planting?

The best potato varieties for summer planting are generally mid-season to late-season varieties that can tolerate the initial warm soil conditions and have enough time to mature before the first hard frost of fall. These varieties often exhibit some level of heat tolerance or have a sufficiently long maturity period to take advantage of cooling autumn temperatures for optimal tuber formation.

Here are some of the most recommended potato varieties for summer planting (for a fall harvest):

1. Kennebec:

   • Type: Main season / Late season (80-100 days to maturity).
   • Characteristics: White-skinned, white-fleshed. Excellent for baking, mashing, and frying. Known for being a reliable producer. Stores well.
   • Why it's good for summer planting: A very dependable all-around potato that performs well in varied conditions and benefits from cooler fall soil for tuber development.

2. Katahdin:

   • Type: Main season / Late season (90-110 days to maturity).
   • Characteristics: Smooth, white-skinned, white-fleshed. Good disease resistance, especially to scab. Versatile in the kitchen.
   • Why it's good for summer planting: A hardy and reliable producer that handles a longer growing season, making it suitable for benefiting from fall cooling.

3. Yukon Gem / Yukon Gold:

   • Type: Mid-season / Main season (80-100 days to maturity). Yukon Gem is a disease-resistant version of Yukon Gold.
   • Characteristics: Yellow-skinned, yellow-fleshed, creamy texture. Excellent for roasting, mashing, and boiling.
   • Why it's good for summer planting: Popular for its flavor and versatility. While mid-season, it's often productive enough to be a good choice for a fall crop, especially Yukon Gem with its disease resistance.

4. Red Pontiac:

   • Type: Mid-season / Late season (80-100 days to maturity).
   • Characteristics: Red-skinned, white-fleshed. Good for boiling, mashing, and potato salads. Tolerates some heat and stress better than other varieties.
   • Why it's good for summer planting: Known for its relative heat tolerance and reliable yields, making it a good choice for summer planting in areas with a decent fall growing period.

5. Nicola:

   • Type: Main season (90-100 days to maturity).
   • Characteristics: Yellow-skinned, yellow-fleshed, waxy texture. Excellent for boiling, salads, and roasting. Good scab resistance.
   • Why it's good for summer planting: A good, dependable main-season potato that can deliver a quality fall harvest.

6. Russian Banana (Fingerling):

   • Type: Late season (90-120 days to maturity).
   • Characteristics: Yellow-skinned, yellow-fleshed fingerling. Waxy texture, superb flavor. Good for roasting and salads.
   • Why it's good for summer planting: If you have a longer fall season, this flavorful fingerling can be a great option.

Key Considerations When Choosing Varieties for Summer Planting:

• Days to Maturity: This is crucial. Calculate backwards from your average first hard frost date. Allow at least 90-120 days for most mid-to-late season varieties. For example, if your first frost is November 1st, planting a 90-day potato by August 1st gives it just enough time.
• Heat Tolerance: Look for varieties specifically noted as having some heat tolerance or those known to perform well in warmer climates.
• Disease Resistance: Summer weather can increase pest and disease pressure. Choosing varieties with good resistance to common potato ailments (like early blight or scab) can increase your chances of success.
• Seed Potato Availability: Finding certified seed potatoes for summer planting can be challenging. Some nurseries or online suppliers specialize in "second crop" seed potatoes available in late spring/early summer.

By carefully selecting potato varieties that align with your climate's specific challenges and opportunities, you can successfully plant potatoes in summer and enjoy a rewarding fall harvest.

How do you prepare the soil for summer-planted potatoes?

Preparing the soil for summer-planted potatoes is crucial for mitigating the challenges of warm weather and ensuring a healthy fall harvest. The focus should be on creating a loose, well-draining environment rich in organic matter that can retain moisture while also supporting efficient tuber development. Proper soil preparation sets the stage for success.

Here’s how to effectively prepare your soil for summer-planted potatoes:

1. Choose the Right Location:

   • Sunlight: Select a spot that receives full sun (at least 6-8 hours daily). While intense heat is a concern, potatoes need sun for vigorous top growth.
   • Drainage: Avoid low-lying areas where water tends to collect. Potatoes are susceptible to root rot in soggy conditions.

2. Clear the Area:

   • Remove Weeds: Thoroughly remove all weeds and plant debris from the previous crop. Weeds compete for water and nutrients, which are critical in summer conditions.
   • Clean Up Old Plants: If you're using a bed that previously had potatoes or other solanaceous crops (tomatoes, peppers, eggplant), it's best to rotate to a different location to minimize disease buildup. If rotation isn't possible, ensure all plant remnants are removed.

3. Loosen and Aerate the Soil:

   • Deep Digging/Tilling: Loosen the soil to a depth of at least 10-12 inches (25-30 cm). This can be done by digging with a spade or broadfork, or by tilling.
   • Why: Potatoes need loose, friable soil for their tubers to expand and form properly. Compacted soil restricts tuber growth, leading to small or misshapen potatoes. Good aeration also prevents waterlogging.

4. Incorporate Abundant Organic Matter:

   • Additions: Generously work in 4-6 inches (10-15 cm) of well-rotted organic compost, aged manure, or other rich organic materials into the top 10-12 inches of soil.
   • Why:
     • Moisture Retention: Organic matter significantly improves the soil's ability to retain moisture, which is vital for summer-planted potatoes that have high watering needs.
     • Drainage & Aeration: It enhances soil structure, improving drainage in heavy soils and increasing water retention in sandy soils. This prevents waterlogging while ensuring consistent moisture.
     • Nutrient Supply: Provides a slow, steady release of essential nutrients as it decomposes, feeding the potato plants throughout their growth.

5. Adjust Soil pH:

   • Potato Preference: Potatoes generally prefer slightly acidic soil pH between 5.0 and 6.0.
   • Test pH: Use a soil pH meter or a soil test kit to check your current pH.
   • Adjustments: If your pH is too high (alkaline), you can lower it by incorporating elemental sulfur or peat moss. If it's too low (very acidic), add a small amount of garden lime (though this is less common for potatoes). Make adjustments well in advance of planting if possible.
   • Why: The correct pH ensures nutrients are available to the plant and helps deter potato scab disease (which thrives in alkaline conditions).

6. Initial Fertilization (Optional, based on soil test):

   • Balanced Approach: If your soil test indicates deficiencies, or if you're not using rich compost, apply a balanced organic granular fertilizer (e.g., 5-10-10 or 5-5-5) at planting time. Avoid excessive nitrogen, which promotes lush foliage but fewer tubers.
   • Phosphorus and Potassium: Potatoes need phosphorus for root development and potassium for tuber formation and overall plant health.
   • Work In: Lightly work any fertilizer into the top few inches of soil.

7. Consider Raised Beds or Containers:

   • If your native soil is particularly heavy clay or has persistent drainage issues, growing summer-planted potatoes in raised garden beds (raised garden beds for potatoes) or large containers (large potato grow bags) filled with an ideal, well-draining soil mix is an excellent alternative.

By thoroughly preparing the soil for your summer-planted potatoes, you create the best possible conditions for overcoming heat stress, ensuring consistent moisture, and promoting the development of a bountiful fall harvest.

What are the best watering techniques for summer-planted potatoes?

The best watering techniques for summer-planted potatoes are focused on providing consistent, deep moisture to the root zone while avoiding both overwatering and allowing the soil to dry out completely. This balance is critical to prevent heat stress, ensure efficient tuber formation, and avoid common problems in hot summer conditions.

Here are the most effective watering techniques:

1. Consistency is Key:

   • Avoid Fluctuations: Potatoes need a steady supply of moisture, especially during tuber formation. Erratic watering (periods of drought followed by heavy watering) can lead to problems like misshapen tubers, hollow heart, or secondary growth.
   • Regular Schedule (with checks): Establish a regular watering schedule, but always check the soil moisture before watering. Don't just water on a set day.

2. Water Deeply and Infrequently:

   • Deep Penetration: When you water, provide enough to thoroughly soak the soil to a depth of 6-12 inches (15-30 cm). This encourages roots to grow deeper, making the plant more resilient to heat and short periods of dryness.
   • Avoid Frequent, Shallow Watering: Shallow watering encourages shallow roots, which are more susceptible to drying out in hot summer sun.
   • Frequency: Aim for watering 1-3 times a week, depending on your soil type, temperatures, and rainfall. Heavy soils will need less frequent watering, while sandy soils will need more.

3. Water at the Base of the Plant:

   • Method: Use a soaker hose, drip irrigation (drip irrigation for potatoes), or a watering wand set to a gentle shower to deliver water directly to the soil around the plants.
   • Avoid Overhead Sprinklers: Wetting the foliage, especially in hot and humid conditions, can promote fungal diseases like early blight and late blight.

4. Timing Your Watering:

   • Best Time: Early Morning: Water early in the morning. This allows the water to soak into the soil before the heat of the day causes rapid evaporation. It also gives any incidental moisture on leaves time to dry, reducing disease risk.
   • Avoid Evening Watering: Watering in the evening means foliage stays wet longer, increasing the risk of fungal diseases.

5. Monitor Soil Moisture Closely:

   • Finger Test: Stick your finger 2-3 inches deep into the soil. If it feels dry, it's time to water.
   • Moisture Meter: A soil moisture meter provides accurate readings throughout the root zone, helping you avoid both underwatering and overwatering.

6. Utilize Mulch:

   • Benefits: Apply a 2-4 inch layer of organic mulch (like straw, grass clippings, or shredded leaves) around your potato plants, keeping it a few inches away from the stems.
   • Why: Mulch dramatically reduces evaporation from the soil, helps keep the soil cooler (crucial for tuber formation), suppresses weeds (reducing competition for water), and moderates soil temperature. This makes your watering efforts much more efficient.

7. Adjust for Hilling/Earthing Up:

   • As you hill up your potato plants (mounding soil around the stems to encourage more tubers and protect them from sunscald), ensure you're still watering deeply enough to reach the lower root zone and the developing tubers.

By meticulously implementing these watering techniques, you can provide your summer-planted potatoes with the essential moisture they need to thrive, even through the challenges of warm weather, leading to a successful and abundant fall harvest.