Sweet potatoes are a great way to get a good return for a medium-sized raised garden bed. They are relatively easy to grow with a tough disposition where bugs are concerned.
The soil conditions are not difficult to create, and the only real challenge you may face is temperature, depending on your location.
We are fortunate to live in a tropical climate, and sweet potato grows like a weed here. In this post, we show the process we use to give some idea of how easy it can be, keeping in mind that planting slips can sometimes be challenging to obtain in some parts of the world.
4 Easy steps to Planting Sweet Potato.
1. Bed preparation
Raised garden beds are great when working the soil because the soil is right there at your fingertips without bending over, which can be painful.
This is one of those times.
To prepare your soil, turn the ground over using a garden fork or small hand tiller while adding manures from cows, horses, sheep, and similar.
Chicken is too high in nitrogen to obtain a decent crop of tubers, but you will get a fantastic harvest of leaves if this is what you want.
Add any other soil amendments you require; blood and bone, compost, etc.
Cover the soil with a good layer of mulch. For more information on this, “Do sweet potato vines need mulch?” is recommended.
We use raised garden beds for growing winter vegetables here in the tropics, like cabbage, tomatoes, celery, and others.
When this season ends and early summer is here, we will plant the following different crops without amending the soil. We grow sweet potato and snake beans in these beds because of the similar attributes to nitrogen in the ground.
The winter leaf growers utilize much of the nitrogen, and both plants don’t require anything added to the soil.
2. Planting Sweet Potato slips.
As you already know, we have sweet potatoes growing wild here, so collecting sweet potato slips is a simple task.
We cut about 18inch or 450mm long growth tips in good condition, pull all the lower leaves off, and only keep the top 4-5 fresh leaves at the end.
Plant the slip in the prepared bed at a depth of 2 inches or 50mm with about 4-6 inches or 100-150mm of the leaf end exposed to sunlight.
Mulch the plants right up to the slip and water them in. Regular watering over the next few days will establish the plants, and you can back off the watering a bit.
Sweet potato slips set roots quickly, and new growth at the tips will confirm your plants are on the way. This link has more information on growing sweet potatoes from starters, in more detail for you.
3. Planting Sweet Potato tubers.
Tubers are another way of planting. If a tuber has sprouted shoots, plant the complete tuber in the garden bed with 2 inches (50mm) of soil over the top.
We will plant tubers if the stock we have in the kitchen gets away from us, and they start shooting new growth. This article titled “sweet potato propagation, tips for backyard food growing” details other ways of starting with this plant if no tubers are ready.
We choose the variety and any available gardens, then plant them if it suits. If we miss the opportunity and the tubers become a bit gnarly, they take a trip to the chicken pen, break down, and return to the soil.
This soil from the chicken pen will end up in the raised garden beds the following winter, already full of organic matter and already fertilized. We have articles on this process here and here and here. (they open in a new tab)
4. Sweet Potato care.
Sweet potatoes are tough plants when it comes to leaf-eating insects. A plant in excellent health should withstand a fair amount of attack from grasshoppers and caterpillars, so a natural organic approach is achievable.
We don’t use any sprays or control agents here, so we don’t have any information on that side of things to share.
Sweet potato vines can be vigorous and take over other areas if you let them.
We either cut the plant back when it gets too wild, or we will throw the vine back on top of itself. We will take the cuttings, give them to the chickens, and keep some for the kitchen.
You can harvest leaves while the underground crop develops, making it a beneficial plant worth growing.
That is the process we use to grow this wonderful vegetable, and it has been effective so far. To cap off the information for you, here are a few common questions asked about growing sweet potatoes.
What type of soil does Sweet Potato need?
Sweet potato needs loose, well-draining soil with good organic content and not heavy in nitrogen to obtain a good harvest.
The sweet potato will grow in many different soil types as long as it is well-draining, and the best results will be from soil that fits the description above.
Sweet potato also grows very well in nitrogen-rich soil, but you will get mostly leaf, as we mentioned above, and very few tubers. A lot of leaves are not that bad as you can eat young sweet potato leaves in cooked meals, and the young fresh tips can be eaten raw.
Sweet potato leaves can be frozen if you have an abundance, but blanch them beforehand.
We use the leaves almost daily in our summer months when the sweet potato is growing rampant in many spots in our yard. We have three varieties in our yard, which require similar conditions.
How deep do garden beds need to be to grow Sweet Potato?
Garden beds need loose friable soil for a depth of at least 8 inches or 200mm for the sweet potato to set a good harvest of tubers.
Deeper is better, but having the soil in the beds tilled to 8 inches will ensure the tubers can grow without constraints.
The sweet potato will grow in hard compacted beds as long as the other conditions and requirements this article mentions are wet. However, from a self-sufficient gardening perspective, we should take every opportunity to obtain a yield.
We have sweet potato growing over our front fence and onto the footpath a little, and the ground is hard in spots, yet every year, we can go out and get a few pounds or kilos of free sweet potato.
We call them footpath potatoes. They are pretty gnarly, to be honest, but they cook up just fine.
Good soil in the garden bed, including raised garden beds, can deliver silly amounts of tubers if the conditions are right.
How much space do Sweet potatoes need to grow?
Sweet potato is a scrambler that loves space, and a single plant can do well in its pot or container, but, in a garden bed, allow spacing of 12-18 inches apart at initial planting.
If your soil is good, you can plant a little closer but be careful not to be greedy and crowd them in. If conditions are perfect for the sweet potato, each plant can take up 4 square feet or over 1 square meter of ground.
The vine can be vigorous in humid tropical conditions like summer, and we seem to be forever cutting back the vines and giving them to the chickens.
Sometimes the chickens eat it, and other times they scratch through it looking for bugs and things.
It eventually breaks down, and when preparing beds for our winter crops, we dig it back up when the chickens have turned it back to great organic soil for the raised garden beds.
What temperature does sweet potato prefer?
Sweet potatoes prefer a minimum temperature of 75F degrees or 24C to grow with the confidence of obtaining a harvest, so a garden bed with full sun is required.
The plant will grow at lower temperatures, but the yield will be completely unreliable.
Commercial growers have been searching for cultivars that meet consumers’ demands more than creating varieties that grow in colder climates.
How much water do sweet potatoes need?
Sweet potatoes require regular watering when grown in well-draining soil.
In poor soil that drains poorly, there is a risk of the tubers rotting in the ground. The plant is a tropical vegetable that is happy with regular heavy rainfall.
It still requires good drainage no matter where it is grown. In the highlands of New Guinea, the sweet potato is a staple crop where they grow it in mounds. These mounds allow drainage, as the soils are often heavy in clay and generally acidic.
The highlands receive a lot of rain, and the sweet potato does well.
How long does it take to grow a sweet potato?
The average time to grow sweet potato in summer from planting till harvest is 4-5 months. Winter plantings can take 8-9 months before harvesting.
The timeframe will depend on the variety you select, but the data above are industry averages within the growing areas of central Queensland, Australia. The climate is sub-tropical with medium annual rainfall.
Your climate is sure to be different, and you can balance climatic variations with grow houses and the like.
When you grow to achieve self-sufficiency in vegetables, it pays to look for and build a list of hardy food plants you can rely on, like the one we put together in this article here.
Few plants are as easy to work with as sweet potatoes.
We have success and believe you can too. Now, get into it.
Article by Tim Blanch for TheTropicalHomestead.com. He is a qualified Permaculture designer.