growing Potatoes
An Easy Soil Mix, Spacing, and Growing Tips
There’s nothing quite like homegrown potatoes. Whether you’re after buttery Yukon Golds, deep purple fingerlings, or classic Russets, growing them in 10-gallon grow bags is a simple and rewarding way to produce fresh spuds without needing a big garden plot. But if you want high yields (and who doesn’t?), it all starts with the right soil mix, proper spacing, and understanding which varieties actually respond to hilling.
An Easy Soil Mix for Potatoes in Grow Bags**
Potatoes thrive in light, well-draining soil with good aeration and plenty of organic matter. If you’re using peat moss as the base, you’ll want to balance moisture retention with drainage. Here’s a mix that gives potatoes exactly what they need:
10-Gallon Potato Soil Mix Recipe
- 4 gallons peat moss (for aeration and moisture retention)
- 3 gallons compost (for nutrients and microbial life)
- 1.5 gallons perlite or pumice (to keep the soil loose and drain excess water)
- 1 gallon vermiculite (for balanced moisture retention)
- 0.5 gallon native garden soil (for microbial diversity)
Amendments for a Bumper Potato Crop
- ½ cup bone meal – Boosts phosphorus for strong roots and tubers
- ¼ cup kelp meal – Provides trace minerals for plant health
- ¼ cup wood ash (optional) – Adds potassium, which improves tuber growth
- ¼ cup gypsum – Prevents hollow heart and rot
- ¼ cup azomite or rock dust – Adds essential micronutrients
Before planting, moisten the mix slightly so it holds together without being soggy. Keep the pH between 5.5 and 6.5 for best results.
How Many Potatoes Should You Plant?
Spacing is key—overcrowding leads to small tubers, and too few plants means wasted space. Here's a quick guide:
| Potato Size | Short Season (70-90 Days) | Medium Season (90-110 Days) | Long Season (110-135 Days) |
|---|---|---|---|
| Small (Fingerlings, New Potatoes) | 3-4 seed potatoes | 3 seed potatoes | 2-3 seed potatoes |
| Medium (Yukon Gold, Kennebec) | 2-3 seed potatoes | 2 seed potatoes | 1-2 seed potatoes |
| Large (Russet, German Butterball) | 1-2 seed potatoes | 1-2 seed potatoes | 1 seed potato |
The key is 4-6 inches of space between each seed potato. Small varieties can handle more per bag, but large potatoes need extra room to size up properly.
Should You Keep Adding Soil as the Plant Grows?
This is where things get interesting. Hilling (adding soil around the stems as the plant grows) is a common practice, but it only works for certain potato varieties.
✅ Indeterminate Potatoes (keep producing new layers of tubers as you add soil)
- Russet Burbank, German Butterball, Carola, Purple Peruvian, All Blue
- Best practice: Add 2-4 inches of soil when plants reach 6-8 inches tall, repeating 2-3 times.
❌ Determinate Potatoes (only form one layer of tubers, no benefit from multiple hillings)
- Red Pontiac, Red Norland, Kennebec, Yukon Gold (partially determinate), Adirondack Blue
- Best practice: Hill once, adding 2-3 inches of soil when plants are 6 inches tall. No need to keep adding more.
If you’re growing determinate potatoes, piling soil past the first hilling won’t help and can actually stress the plant. But if you’re growing indeterminate potatoes, hilling boosts yield by encouraging more tubers along the buried stem.
Maintaining Potatoes Using Korean Natural Farming (KNF)
If you want to grow healthier potatoes with fewer inputs, Korean Natural Farming (KNF) is a great way to boost growth, protect against disease, and enhance soil life. Here’s how you can apply KNF principles to your potato grow bags:
1. Fermented Plant Juice (FPJ) for Growth
- Use FPJ made from vigorously growing plants like comfrey, stinging nettle, or sweet potato vines.
- How to apply:
- Dilute 1:1000 (about 1 tsp per gallon of water) and spray onto potato foliage once a week.
- This provides growth hormones and minerals that encourage strong stems and tubers.
2. Fermented Fruit Juice (FFJ) for Tuber Formation
- Use FFJ from bananas or squash to promote carbohydrate storage in the tubers.
- How to apply:
- Start applying at flowering stage, diluted 1:1000 in water, once every 7–10 days.
3. Indigenous Microorganisms (IMO) for Soil Health
- Introducing IMO improves soil structure and boosts microbial diversity.
- How to apply:
- Mix IMO-3 or IMO-4 lightly into the grow bag soil before planting.
- You can also use a diluted IMO spray (1:1000 in water) every 2 weeks to maintain soil health.
4. Calcium Phosphate (CaP) for Strong Tubers
- Prevents hollow heart and rot in potatoes.
- How to apply:
- Apply CaP spray at 1:1000 dilution when tubers begin to set (around flowering).
5. LAB (Lactic Acid Bacteria) for Disease Prevention
- Prevents soft rot and strengthens plant immunity.
- How to apply:
- Spray LAB solution at 1:1000 dilution once every 2 weeks.
Using KNF, you improve potato resilience, reduce the need for fertilizers, and encourage natural, healthy growth.
What Temperatures Do Potatoes Need?
Potatoes are a cool-season crop, but they have their limits:
- Minimum soil temp for sprouting: 45°F (7°C)
- Optimal growth range: 60–70°F (15–21°C)
- Heat stress begins: Above 80°F (27°C) (tubers stop forming)
- Cold damage: Below 29°F (-1.5°C) (frost kills foliage)
If frost is coming, cover plants with row covers or mulch to protect them. In hot climates, provide shade during the hottest part of the day to prevent stress.
Final Thoughts
Whether you’re growing in a garden or stacking up grow bags, potatoes are one of the most rewarding crops to grow. Just match your variety to the right hilling technique, space them properly, and give them the nutrient-rich, well-draining soil they need. Do it right, and you’ll be harvesting pounds of homegrown potatoes with minimal effort.
