Besides being delicious in almost every possible way, sweet potatoes are one of the most nutritiousveggies we eat. Luckily for us gardeners, they’re also extremely easy to grow! We only need to follow a few key tips and at the end of summer we can harvest enough sweet, juicy big sweet potatoes to last all winter.
Dig Deep
In my 15 or so years of growing sweet potatoes, I’ve learned a few lessons. I’ve found that simply starting with a well prepped site can allow a very respectable harvest with very little work after planting. Raised beds are ideal for sweet potatoes, not just because they encourage loose and un-compacted soil (which sweet potatoes love), but they are easy to harvest from. You can even grow sweet potatoes in large pots or buckets! If raised beds are not possible, dig down into your planned bed at least 12” and create mounded rows or hills for each plant. This adds extra inches for tuber development. As you prep your beds, make sure to incorporate plenty of organic matter. Rotted leaves, compost, and composted manure are excellent choices.
Don’t be Too Eager to Get Started
Equally as important to loose and fertile soil is temperature. Being native to Central and South America, sweet potato plants have zero tolerance to cold temperatures, and should not be planted out until the soil has reached 60°F. This can be sped up in cooler climates by spreading out black plastic for a few weeks before your last frost date, but in zones 7 and above it’s not likely to be necessary. From planting to harvest time is 90 to 120 days depending on the variety, so if you have a shorter growing season, choose a hardier variety.
Water Well
Every year I plant my slips and am sure they aren’t going to make it, and after a week of looking like death warmed over, they wake up one morning looking like they are meant to be there. The first two weeks are crucial for establishment, so keep them well watered during this time. But don’t let them get too dry during their growth either. Sweet potatoes will be overly stressed if they get too dry, and a stressed plant will not put energy into tuber growth. Like the rest of your garden, about 1” of water a week is a good guideline.
Keep the Vines in Check
Most sweet potatoes are vining in nature, and enthusiastic ones at that. Left on their own to grow, they can quickly spread to every corner of your garden, which can be a lovely living mulch, but if you want big tubers, you’ll need to keep the vines snipped back to within 3 feet of the mother plant. In our growing climate there is only enough timeforsweet potatoes to form their tubers under the parent plant, so all those extra vines are just pulling energy from the tubers and putting it into vine growth. Keeping them regularly pruned also allows for easier harvesting as it’s easier to find where you originally planted. It’s not a waste though, sweet potato greens are delicious!
The Right Fertilizer is Key
Sweet potatoes are the crop that made me a believer in having my soil tested as part of my pre-garden prepping. I got lucky the first year I planted them, and had a beautiful harvest of large, tasty tubers. The second year I was not so lucky, and while I had luscious and healthy greens, I got barely any potatoes, the ones I did pull were stunted and scrawny. The culprit? Too much nitrogen in my soil! When you have high levels of nitrogen in your soil naturally or because of things you are adding, (wood chips and chicken poop for example) you will get lots of leaf growth, but very little fruit development. Do yourself a favor and contact your county extension agency to find out how to conduct your own soil test. This will give you a good baseline on your soil health, and what you can safely add as a fertilizer without throwing things out of balance. If it is too late this season to get a soil test in time for planning and planting, when it comes to feeding your sweet potatoes err on the side of caution and use a fertilizer that is lower in nitrogen than it is in potassium and phosphorus. You should read up on this if you’re not schooled on it, but for quick reference, nitrogen is the first # in the NPK sequence. Bone meal, kelp meal, and green sand are my favorite organic choices for sweet potatoes that are lower in nitrogen than potassium and phosphorus. Don’t over-fertilize! Sweet potatoes are not heavy feeders, so these should just be an occasional snack if your soil is less than ideal.
Follow these 5 easy tips and you will soon be able to brag about the 2 pound (or more) big sweet potatoes you dug up this year!
 | Article Written by:Angie Lavezzo |
| About the Author:Angie Lavezzo is the former general manager of Sow True Seed. Beyond her professional role at Sow True, Angie's passion for gardening extends into personal hands-on experience, fostering plants and reaping bountiful harvests. |
FAQs
Place cut potatoes 10-12 inches apart in the trench. If larger potatoes are planted whole they will produce larger plants and should be given a little extra room, 12-16 inches. A spacing of 36 inches between rows in adequate but if you have the extra space, further spacing will make hilling easier.
How do you make potatoes grow bigger? ›
Place cut potatoes 10-12 inches apart in the trench. If larger potatoes are planted whole they will produce larger plants and should be given a little extra room, 12-16 inches. A spacing of 36 inches between rows in adequate but if you have the extra space, further spacing will make hilling easier.
How do you prepare soil for sweet potatoes? ›
Plant sweet potatoes in warm soil about a month after the last spring frost. Space sweet potato plants 12 to 18 inches apart in damp, loamy soil with a pH of 5.8 to 6.2. Before planting, improve your native soil by mixing in several inches of aged compost or other rich organic matter.
What is the best fertilizer for sweet potatoes? ›
Choose the Right Fertilizer: Select a balanced, all-purpose fertilizer with equal parts nitrogen (N), phosphorus (P), and potassium (K). A fertilizer labeled as 10-10-10 or similar works well for sweet potatoes.
Do sweet potatoes need a lot of water? ›
Newly planted sweet potato slips will need to be watered daily during their first week outside. Watering every other day during the second week will help establish plants. Once the plants are established, sweet potatoes can be watered once a week.
What makes sweet potatoes grow bigger? ›
You can even grow sweet potatoes in large pots or buckets! If raised beds are not possible, dig down into your planned bed at least 12” and create mounded rows or hills for each plant. This adds extra inches for tuber development. As you prep your beds, make sure to incorporate plenty of organic matter.
What nutrients do potatoes need to grow big? ›
Nutrient Requirements
A potato crop makes a large demand on the soil nutrients. An average acre of 300 cwt/ac potatoes will utilize 200 pounds of nitrogen, 60 pounds of phosphorus, and 300 pounds of potassium. One third to one half of these nutrients are found in the vines and returned to the soil.
What do sweet potatoes need to grow well? ›
Sweet potatoes grow best in light, sandy soils but grow well on heavier soils, high in clay and amended with organic matter. Full sun requires direct light at least 6 hours/day; prefers 8 - 10 hours/day. Days to maturity: 85 - 120.
Do sweet potatoes grow on a vine or under ground? ›
Sweet potatoes are part of the morning glory family, so they grow like typical tubers, underground with trailing vines above ground.
How to encourage sweet potatoes to sprout? ›
Starting Sweet Potato Slips in Water
Push three or four toothpicks into the sweet potato to hold the sprouting end above the water. Set the lower end (the rooting end) in a jar of water and wait for your slips to form. It may take several weeks. Detach them and place them in water where they will develop roots.
If you love growing sweet potatoes, this fertilizer guide is for you. Learn how to nurture your sweet potato plant with simple items like coffee grounds, egg shells, and more. Follow this guide to soil health, and harvest sweet potatoes with ease.
What not to plant next to sweet potatoes? ›
Squash will compete with Sweet potatoes for space: these vigorous growers like to spread out. Prevent problems by not planting any members of the Solanaceae family (potato, tomato, all peppers, ground cherries (tomatillo), and eggplant) in the same spot next year.
How do you make sweet potatoes grow faster? ›
To Recap:
- Don't add nitrogen or too much compost to the soil.
- Make sure your soil has enough phosphorus, potassium, and minerals.
- Soil should be a sandy-loam.
- Grow in full Sun.
- Give them lots of water.
- Wait until the right time to harvest.
- Grow the right variety for your area.
The best soil for sweet potatoes is loose and rich in organic matter. In the garden, mix some well-aged compost into each planting hole and then plant slips 12-18" apart, burying the stem with soil right up to the first pair of leaves.
Can you cut a sweet potato in half and plant it? ›
To start your slips, you need several healthy, clean sweet potatoes. Each sweet potato can produce up to 50 slip sprouts. To create sprouts, carefully wash your potatoes and cut them either in half or in large sections.
Can you plant a whole sweet potato? ›
If a whole sweet potato is placed in the ground in early spring — when white potatoes are usually planted — the cold weather will inhibit its growth and it might rot. For this reason, the recommended propagation technique for sweet potatoes is to plant “slips” after the last frost date.
What makes potatoes bigger? ›
Correct balanced nutrition is important for increasing potato tuber size. Nitrogen, phosphate, potassium, calcium, magnesium and manganese have all been shown to have effects on potato tuber size.
Is Epsom salt good for growing potatoes? ›
The amount of Epsom salt you should apply to your potato crop depends on several factors, such as soil magnesium content, potato variety, and growing conditions. However, as a general rule, 1 tablespoon of Epsom salt per gallon of water is a safe and effective dosage for most potato varieties.
