Sweet potato is a great vegetable to grow; it is easy to create new plants from existing plants. This process is called growing from starters, and it is a simple way to plant your way to sweet potato abundance.
In this article, we go into making new plants that can give you more vegetables at zero cost if you already have a plant or know someone who does. The process is straightforward and applies to all sweet potato varieties that we know, so let’s get into it.
How do you make a sweet potato starter?
Sweet potato starters are made by removing about 12-18 inches (300-450mm) of plant material from the vine and removing all but the tip leaves from the stem.
The sweet potato plant is a vine that can be vigorous when the conditions are to its liking, and this is an excellent opportunity to make more plants from an existing vine when it is rampant.
The new growth at the ends of the vines can be cut from the main plant, and as long as a few leaves are left on the growth tip and all others removed, this can be the creation of an entirely new plant that will be an exact clone of the variety it came from.
This is a great way to spread a favorite sweet potato around your garden if you have the space.
Do starters need to be in water to make roots?
Sweet potato starters don’t need to be rooted in water before planting into soil. If the soil temperatures in the garden where you intend to grow it are still cool but are beginning to rise, this method is suitable.
Often the vine is already waiting for you with roots growing from the leaf nodes. A new plant is ready to grow once you cut the stem and stick it in the ground.
When should you start sweet potato slips in water?
Rooting sweet potato starters indoors in water is good when the soil temperatures are still too low for the plant to grow in the garden or the area where you want to grow it has not been properly prepared.
This method is a great way to get a head start on this crop even if the temperatures are warm outside, but the intended area where you want to grow the sweet potato is occupied with another crop close to harvest.
It is also a great way to get kids involved in growing vegetables as they can watch the progress over a few weeks as the roots arrive and develop.
This method overlaps growing time for different plants and allows you to make the most from a smaller garden area; however, it is worth keeping tabs on the types of plants suitable for the sweet potato to follow as a crop.
Mustard greens are a good crop before the sweet potato as the leaves can be harvested as a table green as the plant grows, and then the plant can be dug into the soil to retard any nematode issues that may be present in the soil.
These nematodes can cause tuber rot in bad cases, so we recommend you rotate your crops to help avoid this issue.
We have several wild patches of sweet potato in our yard, and we seem to have been lucky so far with this nematode family because the plants still produce, and it has been in the same spot for five years or more.
How do you plant a sweet potato starter?
Planting a sweet potato starter is a simple task of forming a 2-inch (50mm) trench in the garden soil where you want the vine to grow and burying the stem leaving the last 3-4 inches (75-100mm) of the vine with leaves attached above the surface.
This should then be watered in well and finally covered with a good layer of mulch. Don’t cover the leaf tips, but the mulch is ok up close to them. It is best to plant these starters as you remove the leaves from the lower stem, which helps the plant with shock.
After a few weeks in the ground, the roots will be visible, and the vine should be actively growing. This image shows the fine roots to look for.
Leaving the starters in a container of fresh water for a day or so is ok if the planting cannot be done straight away.
As we note elsewhere in this article, the starter does not need to have roots at this stage, and this is entirely up to you and your situation whether you plant straight into the ground or root it beforehand. Soil temps best govern this choice.
Are sweet potato starters and cuttings the same thing?
We consider cuttings to be the same as slips and starters. They are just different terminologies to describe the same part of the plant.
There is a bit of confusion on this, and for this post, we discuss the two methods we have had the most success with. Sweet potato starters are, just as we have described above, growing with living plant material that is above ground.
This is the method that most commercial growers use as it is pretty simple and effective if the mother plant is healthy and vigorous. Multiple starters can be taken from an individual plant without causing too much stress on it.
For more ways to get sweet potato going, “sweet potato propagation, tips for backyard food growing” is worth investigating.
Another method we use to grow sweet potatoes is from tubers that have sprouted new growth. This method allows you to grow sweet potatoes from store-bought tubers or roots and is an excellent way to test the flavor of the potato variety before you grow it.
The growth tips can be cut from the main potato if the growth is just at one end of the tuber, or if the sweet potato is covered in shoots like this one in this image shows, it can then be planted as it is in moist soil.
Care should be taken with the young growth tips as they are susceptible to damage and can easily break off. Roots will form from the cut section of the tuber if you have cut a chunk off that has sprouted.
What produces more tubers, slips or root cuttings?
The sweet potato yield is essentially a derivation of the soil conditions. Be aware of the soil type, as sometimes the soil can be too rich for a root crop. This post details making organic soil for raised garden beds, and it explains soil in more depth for you.
It doesn’t matter what method you use to propagate this plant because if the soil conditions are prime, the plant will produce a reasonable harvest, and if the conditions are poor, the yield will likely follow suit.
The commercial growers tell us that the starters, or slips, will produce a sweet potato at every location along the stem where a leaf was removed before planting it and covering these leaf nodes with soil.
We find that while these node locations produce some tubers, the vast majority of the sweet potatoes come from where the growing vine puts down roots as it grows, and these roots then often set a tuber.
When is the best time to start sweet potato slips?
The best time to start sweet potato slips is at the end of the colder seasons. Our plants take off when we get our first wet season storms and continue to ramp up growth as the humidity climbs and the rainfall becomes consistent.
Your climate will likely be quite different, so things to keep an eye out for are the soil temperatures and the moisture levels. Sweet potato vine loves warmth and moisture, so use this to gauge when you need to get going on the sweet potato starters. We have a dedicated beginner’s guide to growing sweet potatoes that you might find helpful. It covers soil conditions and raised garden beds.
Be careful with any fertilizer you want to apply because nitrogen-heavy mixtures will give lots of green leaves and very few sweet potato tubers. We don’t apply manufactured fertilizers and only use mulch and compost. Relevant questions are answered in “Do sweet potato vines need mulch?”.
Growing sweet potato from starters is probably one of the easier vegetables, and the results can be good once you understand how this plant grows.
It is a plant that can be kept alive indoors in cold climates with care, and then once warm weather is close, it can be ready for inground planting.
Article by Tim Blanch for TheTropicalHomestead.com. He is a qualified Permaculture designer.