The definitive guide on How to Grow SWEET POTATO SLIPS


Sweet potatoes are a major root crop for most developed countries, they have fantastic flavour are packed with nutrients and have become a staple for 90% of Europe, Asia and Africa. Their origins hail from the tropical Americas, this plant is part of the morning glory (Convolvulaceae) family.

What are sweet potato slips

What are sweet potato slips? They are the sprouting shoots that grow out of the sweet potato tubers. Sweet potatoes do not grow from seed, you need to produce slips from a tuber and then grow these on to propagate a sweet potato plant.

What do sweet potato slips look like?

Slips are large shoots that grow from a sweet potato tuber. They grow upright like any other vine and has elongated heart-shaped leaves along this vine. They vary from bright green through shades of purple or can be variegated.

How to grow sweet potato slips

As already mentioned, sweet potatoes are not grown from seed. They must be grown from slips. These slips originate from tubers of sweet potatoes. There are various ways to grow slips from sweet potatoes and two of the most popular are below:

  • Toothpick method (In water)
  • Soil Method

How to grow sweet potato slips in water?

This method of growing sweet potatoes can be a much longer drawn-out process than the soil method. I have used both methods pretty much every year for the past 10 years and ALWAYS have better and faster results with the soil method. But to ensure I provide you with all the information possible I am also including this method as it does work.

For the toothpick method, you stick 3 or 4 cocktail sticks into a sweet potato, approximately halfway up the length of the tuber. Place this into a glass jar and fill with clean tepid water until about 2 inches of the bottom of the tuber is covered in water. This is then placed on a south-facing windowsill, or better still in a lit heated propagator such as the Vitopod I use here.

It is important to provide good light and heat for the tuber to start to root. This will send roots into the water and eventually will sprout some shoots. These will start to grow slowly at first. As the plant grows a larger root system these shoots will grow quicker and become more prolific. It may become necessary to ensure water levels do not drop. It may also be required for you to change water intermittently to prevent the tuber rotting.

How to grow sweet potato slips in soil

The soil method for me is a much more reliable way of growing sweet potato slips. For this method simply fill a seed tray with compost and lay the tuber on its side burying it between a third and half its depth. Water the compost well and place in warm south-facing windowsill or propagator.

Providing bottom heat with this method will really speed up results. Although you will not see the root system being created due to the compost, it will be growing much quicker than the toothpick method. Keep the soil moist at all times allowing the shoots to grow to around 6 inches high. Like with the toothpick method the sweet potato tuber becomes more prolific as the root system grows.

What to do with the sweet potato slips as they grow?

With both the methods above it is important to remove the slips from the potato, this has a few benefits for the potato. It allows it to keep producing new slips, and also prevents the potato from becoming exhausted.  Remove slips from the potato when they reach a size of around 6 inches high. Simply snap them from the point where they join to the tuber. DO NOT CUT the slips, they must be torn from the tuber.

This will leave a little heel on the slip. Simply place these into a glass of water to start to root. Over a period of about 7-10 days, you will see a root system appear. This is the point when you can pot them up like any other seed start.

Do sweet potato slips need to be rooted before planting?

Alternatively, you could skip this process and pot up straight away after breaking them off the mother tuber. I prefer to see them rooting before potting them up. It allows me to know a good root system is being formed before using resources and time on a plant that might not make it.

Is it worth using rooting hormone for sweet potato slips?

Unlike a lot of other cuttings, sweet potato slips do not require a rooting hormone. They readily root along the length of their vine at each nodule. In fact, you can create a much larger root system with very long slips by removing their leaves and burying the stem on its side. This will root from each junction node.

Water and feeding

Carry on raising the plants watering and feeding as required. Use a high nitrogen feed to start with, something like a tomato feed or seaweed feed would be idea later switching to a high nitrogen, potassium and calcium feed. This will help when forming its tubers.

When to plant sweet potato slips into the final growing site?

Move the slips from one size pot to the next and protect from frosts. Keep moving on until the last frost date has passed then you can plant into their final growing areas. Depending on where you live will depend on the way you need to grow your sweet potatoes. They prefer very warm growing conditions.

What growing methods are the for sweet potato slips?

Final growing areas may just be the ground in warmer climates, but if you live in areas that don’t see crazy heat like the UK, for instance, you may wish to consider growing in a greenhouse or high tunnel. The three options you have are:

  • Growing in the ground
  • Growing in raised beds
  • Growing in containers

Growing in the ground

As mentioned above, to grow outside in the ground you need the tropical heat of America or Australia. This will provide ideal conditions to be able to grow in the ground. In colder climates, though tuber formation will be sparse and the tubers that do form will be very small with no bulk to them.

Growing in raised beds.

In colder climates, this is a good idea. Providing it is undercover as this not only provides the space required for the vines to sprawl and grow but also the soil in the raised bed warms much faster than the ground. Therefore, you can start your crop earlier giving them as longer growing season.

Growing in containers

Again, for colder climates, this is a good idea. I use 30-litre tree containers with handles to grow mine. These are ideal as they are black in colour, the vines are required to take up the nutrients as the root zone is constricted and vines can be trained up a trellis which helps to save valuable space in a greenhouse or high tunnel.  

So now we have a good idea of what we need to grow sweet potato slips at home, and how to continue to grow them throughout the season. Let’s take a look at some of the details.

Check out my video below to see all of this in action and get some more tips and tricks.

When to start sweet potato slips indoors

The earlier you can start to produce sweet potatoes the better. If you live in a cooler climate then aim for around 3 months before your first frost date. I start mine at the beginning of February. This allows me to not only get good-sized plants by May which is the last frost date but will also allow me to get sufficient quantities of slips to produce the desired crops I am after. Living in the UK means I would have to start early, but the list below may help you better decide when to sow yours

When to start sweet potato slips in your country or zone? From zone 7a you could wait until later in the year as frost dates are relatively soon in the growing year.

Zone 2a / 2bFeb 28th
Zone 3a / 3bFeb 20th
Zone 4a / 4b Feb 1st
Zone 5a / 5bJan 29th
Zone 6a / 6bJan 26thth
Zone 7a / 7bJan 14th
Zone 8a / 8b  Dec 18th
Zone 9a / 9bNov 22nd
UK SouthFeb 14th
UK NorthMarch 1st

Zones 7, 8 and 9 could get away with not planting so early as their last frost date is early enough in the growing season to be able to catch up and put the slips straight out to the growing spaces.

When are sweet potato slips ready to plant

As soon as a root system appears you can pot up slips into their own individual containers. Keep them warm and under lights until it is warm enough to transplant them into their final growing spaces. This could be sped up if your greenhouse or high tunnel is heated.

How many sweet potato slips per container?

As I mentioned above, I use 30-litre containers. 1 slips per container would be an ideal amount to use. Placing more in a container could affect the crop

How many sweet potato slips per square foot?

When you only have a square foot of space you need to plant just one sweet potato slip per square foot. An 8 x 4 bed could hold 32 slips. However. This rule can be broken the deeper the bed, pushing it to more around 9” per plant due to the volume.

How many sweet potato slips per grow bag?

Grow bags are usually around 3 ft x 1 ft and therefore it’s possible to grow 3 per bag, however, due to the depth of the soil I would consider growing just 2 per grow bag.

When to harvest sweet potato slips?

The longer you can leave it to harvest your sweet potatoes the better. However, typically this takes around 4 months for a good crop. If you live in cooler climates grow until the foliage starts to die back. The leaves will turn yellow like normal potatoes. If growing indoors in a greenhouse you can leave them in the ground, but ensure you harvest before the first frost.

Why grow your own sweet potato slips?

Sweet potatoes slips are expensive to buy. Typical pricing in the UK is around £2.50 per slip while in the USA they are less costly being able to purchase around $1.75 per slip. In Australia, the price is approximately 6.95 per slip

Growing your own slips can save you a lot of money. It allows you to also grow whatever varieties you wish rather than being tied to what is available. One other added benefit is you get to start your slips off when you are ready and not when you are told to be ready by the plant distributors.

Where to buy sweet potato slips?

Should you decide you would rather buy sweet potato slips overgrowing your own, you can purchase them online on many websites. Garden centres and big box stores will also offer them for sale.

If you would like to purchase sweet potatoes to create your own slips from then you can use store-bought sweet potatoes providing, they are organic. Avoid using those that are not organic as these will have been sprayed with a sprout inhibitor. Consider other gardeners or gardening groups as these can be a great way to source and swap varieties that you may not be able to get commercially.

Can you eat sweet potato slips?

The great thing about sweet potato slips is that even the foliage is edible. It’s great to be used raw in a salad or cooked in a stir-fry or as an ingredient in other cooked dishes. They can be prepared much like spinach but like most greens can be somewhat bitter.

What to do if your sweet potato has roots but no slips?

This usually happens when you are using the toothpick and water method. To get the potato to produce slips you need to remove the potato from the water and plant it in the soil leaving the surface of the potato above the soil. With a week you should start to see the first slips starting to form.

How long do sweet potato slips take to grow?

Usually, you will see roots and slips starting to grow from the tuber within 2 to 3 weeks. It can be sooner, but sometimes it takes this amount of time for the potato to realize it has ideal conditions to start growing.

How to store sweet potato slips before planting?

As mentioned above, slips need to be potted on and kept above 15˚C or 59˚F in good light until they are ready to be planted into their final growing space. Soil should be kept damp but not sodden.

How to harvest and store sweet potatoes

Simply dig your potatoes out of the ground or container when the foliage has turned yellow. It is ok to leave them in the ground but remove this foliage. They must be harvested before the first frost. At the time of harvesting leave the tubers on the soil surface in the sunshine for a few hours to cure.

Once the completely cure you can store them exactly the same as potatoes. Although I have not made a video for storing sweet potatoes the video below shows many ways to cure and store normal potatoes. Using these methods will allow you to keep your potatoes long term right throughout winter.

Store potatoes long term

Varieties of sweet potato to grow at home

So now we know all there is to grow sweet potato slips at home. Now, what varieties are there that you could grow? The list below is just some of the varieties available for gardeners like us to grow at home

List of sweet potato varieties

AcadianGold Rush
All GoldGolden Belle
AmericanaGold Mar
ApacheGrand Asia
Australian CannerHannah Sweet
AyamurasakiHayman White
BakerHeartogold
BeaureguardHerandez
BonaraHiDry
CampeonHoolehugold
CanbakeHoolehured
Caro-GoldJersey Red
Carolina BunchJersey Yellow
Carolina NuggetJewel
Carolina RubyKandee
CaromexKona B
CarverNancy Gold
CentennialNorthern Star
ChipperOrlis
CovingtonPapota
Coastal redPope
Copper GoldRanger
CordnerRapozer
CreoleRed Diane
DerbyRed Glow
Don JuanRegal
EarlyportRuddy
Early sweetScarlet
EurekaSumor
EvangelineTango
ExcelTopaz
GarnetTravis
Georgia JetVardaman
Georgia RedWhite Delite
White StarYellow Yam

With so many varieties above you have plenty of options of flavours and colours to choose from. Simply pick your cultivar and get growing.

Conclusion

That’s it. Everything you need to know in order to produce sweet potato slips at home and do it without the headaches that so many people really struggle with. Knowing these tips and rules should help you with getting a great harvest

I hope you enjoyed this blog post about the definitive guide on How to Grow SWEET POTATO SLIPS? I trust it answered your question fully. If this was of interest to you, why not consider checking out some of my other blog posts and subscribing to the blog so you don’t miss future content.

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Remember folks; You Reap What You Sow!

Tony O'Neill

I am Tony O'Neill, A full-time firefighter and long term gardener. I have spent most of my life gardening. From the age of 7 until the present day at 45. My goal is to use my love and knowledge of gardening to support you and to simplify the gardening process so you are more productive

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