With their similar names and starchy tubers it’s natural to wonder – can you plant sweet potatoes and regular potatoes together? The short answer is yes! Despite the name similarities, they are completely unrelated plants with different origins and growth habits.
Growing sweet potato vines alongside potato plants works well However, some considerations for their different needs will ensure a bountiful harvest of both tasty tubers.
Sweet Potatoes and Potatoes Have Different Requirements
Sweet potatoes (Ipomoea batatas) and potatoes (Solanum tuberosum) are not closely related at all. Potatoes belong to the Solanaceae or nightshade family, while sweet potatoes are morning glories. This means:
- They don’t compete for nutrients or crowd each other out
- They are not susceptible to the same diseases
- They can make great companion plants!
However, sweet potatoes and potatoes do have some differing requirements when it comes to:
- Climate and growing season
- Soil properties
- Planting methods
- Care and maintenance
Understanding these differences is key to success when interplanting the two tuber crops together.
Sweet Potatoes Need Heat, Potatoes Prefer Cool
The most significant difference between sweet potatoes and potatoes lies in their preferred climates.
Sweet potatoes thrive in hot, humid climates with long growing seasons. They require at least 3-4 frost-free months with temperatures from 75-85°F to produce well.
In contrast, potatoes grow best in cool conditions around 60-70°F. They can tolerate light frosts. A shorter 90-120 day growing season suits them perfectly.
This means timing plantings accordingly:
- Plant potatoes 2-3 weeks before the last expected spring frost when soil warms to 45°F.
- Delay sweet potato planting until 2-3 weeks after the last frost date, around 60°F soil temp.
Choose early maturing potato varieties and late maturing sweet potato cultivars. This allows both crops to grow during their ideal seasons even when planted together.
Soil Prep Differs for Potatoes and Sweet Potatoes
Preparing the soil properly before planting sets up both tuber crops for success. Ideal soil properties vary slightly between the two:
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Potatoes grow best in loose, fertile soil with a slightly acidic pH around 5.5-6.5. They like moderate fertility and organic matter.
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Sweet potatoes prefer light, sandy soil with a more acidic pH between 5.0-6.2. They need low nitrogen and moderate phosphorus and potassium.
When planting both, aim for pH around 6.0-6.5. Incorporate 2-3 inches of compost when preparing beds to increase fertility and provide nutrients for tuber development in both crops.
If soil test shows very low phosphorus or potassium levels, use an organic fertilizer blend like 5-10-10 at planting time to give sweet potatoes what they need to thrive.
Planting Methods Differ Between Potatoes and Sweet Potatoes
Potatoes and sweet potatoes have very different planting methods and spacings:
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Potatoes are planted from small whole or cut seed tubers buried 4-6 inches deep, 12-15 inches apart in rows 2-3 feet apart.
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Sweet potatoes are planted from leafy transplants called slips. Slips are buried shallowly with just the roots covered, 12-15 inches apart in rows 3-4 feet apart.
Adjust row spacing accordingly, but the plants can overlap just fine. Allow at least 2-3 feet between potato and sweet potato rows.
Stagger planting rows in a zig-zag or checkerboard pattern to maximize space for both vine crops.
Sweet Potatoes and Potatoes Have Varying Care Needs
Once planted, potatoes and sweet potatoes have some subtle differences in their ideal growing conditions:
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Potatoes thrive in consistently moist soil. Water 1 inch per week. Hill soil around plants as they grow.
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Sweet potatoes need drier soil and should not be overwatered. Wait 2 weeks after planting before mulching.
Both benefit from black plastic mulch to warm the soil, conserve moisture and reduce weeds. Avoid fertilizing with high nitrogen once plants are established.
Can You Plant and Harvest Both Crops Together?
Due to their different maturing times, potatoes and sweet potatoes should be harvested separately:
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Potatoes mature earlier, around 2-3 months after planting once vines start dying back.
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Sweet potatoes take up to 4 months to mature. Harvest after vines yellow but before a hard frost.
Stagger your harvests accordingly. Cure potatoes first for 1-2 weeks in a dark, cool spot before storing them long-term. Sweet potatoes are best cured for 2-3 weeks in warmer conditions after digging.
Tips for Success Growing Both Tuber Crops
Here are some useful tips to ensure a plentiful harvest of both potatoes and sweet potatoes in the same garden:
- Test soil and amend as needed before planting
- Choose short season potatoes, long season sweet varieties
- Allow enough space between rows for both vines
- Plant potatoes 2-3 weeks before sweet potatoes
- Adjust watering practices to meet each crop’s needs
- Fertilize lightly with organic balanced fertilizer
- Harvest and cure potatoes first, then sweet potatoes
With a little planning, there’s no reason you can’t enjoy a bountiful harvest of two amazing staple crops. The key is understanding and accommodating their differences. Give your sweet potatoes and potatoes the space, time and care they need, and your harvest baskets will be overflowing with tasty tubers.
Companion Planting with Sweet Potatoes and Potatoes
Interplanting compatible companion crops with potatoes and sweet potatoes can maximize garden space and improve yields. Here are some options that grow well planted alongside both:
Good Companions for Potatoes
- Peas
- Beans
- Corn
- Cabbage
- Eggplant
- Marigolds
- Nasturtiums
Good Companions for Sweet Potatoes
- Green onions
- Lettuce
- Radish
- Spinach
- Dill
- Oregano
- Marigolds
Great Companions for Both
- Carrots
- Beets
- Parsnips
- Garlic
- Onions
- Leeks
- Chives
Just be sure to allow adequate room for all plants to grow. Also take into account differences in soil nutrient needs when adding companion plants. With smart companion planting, you can get two bountiful tuber harvests along with other delicious veggies too.
Frequently Asked Questions About Growing Potatoes and Sweet Potatoes Together
Here are answers to some common questions about interplanting these tasty tuber crops in the garden:
Do potatoes and sweet potatoes cross-pollinate?
No, potatoes and sweet potatoes do not cross-pollinate since they are completely unrelated species from different plant families.
Can potatoes and sweet potatoes share diseases?
No, they are not susceptible to any of the same diseases so disease risk is low. Rotate planting sites to avoid any buildup of soil pathogens over time.
Should potatoes and sweet potatoes be planted in separate raised beds?
Not necessarily – planting in the same raised bed works fine as long as proper spacing and crop needs are provided for. Just allow adequate space between rows.
Is liquid fertilizer better than granular when planting both?
Either works, just avoid over-fertilization. Liquid fish emulsion or compost tea can provide a nutrient boost to both crops during the growing season.
Can potatoes and sweet potatoes be stored together after harvest?
No, keep potatoes and sweet potatoes separate for storage. Potatoes like cool, humid conditions while sweet potatoes need warmer, drier storage. Curing requirements also differ.
Enjoy Double the Tasty Tubers
If managed properly by selecting suitable varieties, amending the soil, and attending to each crop’s growth needs, potatoes and sweet potatoes can be grown together quite successfully.
Take advantage of their different growth habits and seasons to maximize your garden space. Then reap double the delicious versatile staple crops. With proper planning and care, you can enjoy potato and sweet potato goodness all season long.
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How to Grow PotatoesA favorite root crop, the humble potato is easy to grow. It will store for many months, and there are countless ways to prepare it over the winter.
- Get seed potatoes from a nearby farm, a reputable nursery, or a seed company. Some seed companies only sell potatoes. You can save your own seed potatoes after you grow your own, though. These aren’t seeds; they’re little potatoes that you cut up and plant. They will be delivered to you at planting time. Keep them cool in your refrigerator. Take them out a week before you plant in mid-spring.
- Meanwhile, prepare your soil. Potatoes are adaptable and will tolerate less than optimal soil. But ideally, it should be loose, drain well, and have a pH of 5 (slightly acidic). 8-6. 5. Potatoes need a lot of food, so till in a lot of good compost.
- Potatoes need full sun and cool weather. Plant when the soil temperature is above 45ºF. Each piece of seed potatoes should have two eyes cut into it. Plant them 12-15” apart in rows 2. 5’ apart, and 6-8” deep with the eyes pointing up. Cover with 4” of soil. They will sprout in a couple of weeks. Fill in half of the sprouts’ holes with soil when they are 8 to 12 inches tall. This is called ‘hilling’. Every two weeks, push the soil back up about halfway around the plants. Continue doing this until the plants flower. Tubers will form in the soil you are hilling up.
- Every week, potatoes need an inch of water, and more when it’s dry. When the plants start to flower, you can dig up new potatoes. When the foliage begins to die back, stop watering. Two to three weeks later, harvest your full-size potatoes. Dig carefully with a dung fork. Damaged tubers are edible, but won’t keep. Put them somewhere dry for a few days to make the skins tough. They store best in cool, dark, humid conditions.
- Aphids, cutworms, wireworms, and flea beetles are just some of the pests that can hurt potatoes. Every three years, turn your potato bed so that pests and diseases like black leg, blight, verticillium wilt, and ring rot don’t get to it. Your potato garden will be healthy if you buy certified, hardy varieties, keep the garden clean, and water from below.
- From the Potato Association of America, these are their favorite potato types. Here’s how to make roasted rosemary and garlic potatoes.