Have you thought about putting sweet potatoes in your garden but don’t know how to begin? That’s how I felt two years ago.
I stumbled my way through the different kinds of information I could find, and in the end, I had some great sweet potato harvests.
I wouldn’t say I know everything there is to know about any garden crop, but this is especially true for sweet potatoes. It was only my second time growing sweet potatoes in 2020, and it was another great year. I think I learned a lot about what to do and what not to do when you first start growing this crop.
We go into all the specifics in this podcast episode and blog post here on the Beginner’s Garden. Listen to the episode below or continue reading. [fusebox_track_player url=https://traffic. libsyn. com/secure/journeywithjill/178_EDITED. mp3].
Sweet potatoes are a popular root vegetable that can be grown in many parts of the United States. They are fairly easy to grow and produce an abundant harvest. However, there is some confusion around when the optimal time is to plant them. This article will examine if it’s too late to plant sweet potatoes.
When to Plant Sweet Potatoes
Sweet potatoes need warm soil and air to grow properly. They thrive in temperatures between 70-85°F. Cooler temperatures below 55°F can damage plants and stunt growth. Most gardeners recommend planting sweet potato slips or sprouts 3-4 weeks after the last expected spring frost. This gives the plants enough warm weather to establish themselves before cooler fall temperatures arrive.
In northern climates, the deadline for planting is usually early to mid June. In southern climates planting can be extended into July. However, the earlier sweet potatoes are planted, the more time they have to size up and produce larger roots. Late plantings in July and August will still produce a crop, but the individual sweet potatoes may be smaller.
So in most regions, it’s not too late to plant sweet potatoes through the end of June. But for best results, try to plant slips by early to mid June if possible.
Growing Conditions
Sweet potatoes prefer loamy, well-draining soil Heavy clay soil can restrict root growth. Amending soil with compost or coir can help improve texture Raised beds and hills also promote drainage and allow soil to warm faster in spring.
Sweet potatoes are not heavy feeders but do require some key nutrients for best growth:
- Phosphorus – promotes root growth
- Potassium – bulks up roots
- Calcium – prevents diseases like scurf
A balanced organic fertilizer can be worked into soil before planting. Fish emulsion or compost tea can also give plants a nutrient boost during the growing season.
Sweet potatoes also need consistent moisture, especially as roots start to size up. Drought stress can reduce yields. Plants should receive at least 1 inch of water per week from rain or irrigation. Mulching around plants helps retain soil moisture.
Choosing a Variety
There are many sweet potato varieties suited to different climates and maturity dates
- Beauregard – classic orange variety, stores well, 90 days
- Centennial – orange flesh, great for northern regions, 100 days
-Georgia Jet – fast growing red skin, orange flesh, 90 days - White Yam – white skin/flesh, heirloom, 100 days
- Vardaman – purple foliage, yellow skin, orange flesh, 110 days
Look for early season varieties if planting later in summer. Read seed descriptions to find ones suited for your growing zone.
Starting Slips
Sweet potatoes are grown from sprouts or slips cut from existing sweet potatoes. To get a head start, potatoes can be placed in moist soil or water 2-3 months before planting time to initiate sprouts. The sprouts are then cut and transplanted into the garden.
Local nurseries, garden centers or online retailers sell pre-started slips. Or slips can be started at home using a potato from the grocery store.
Curing and Storing
After harvest, sweet potatoes should be cured to convert starches into sugars and help wounds heal over. To cure, store freshly dug potatoes in a warm, humid place around 85°F for 7-14 days. Afterwards, they keep for several months in a cool basement around 55°F.
What is a sweet potato slip?
I mentioned above that sweet potatoes are planted as “slips. ” They aren’t seeds, and they aren’t really transplants. A slip, instead, is a small, rooted piece that develops from the previous year’s sweet potato crops.
Sweet potato slips are comprised of leaves growing up and roots growing down. When it’s time to plant, you plant them like you would any other transplant. But how do you obtain sweet potato slips?.
You have two options: You can grow your own slips or you can buy them. I used slips from the harvest the year before to grow plants the following year. Before we talk about growing your own slips, let’s consider the easiest route: buying slips.
Sweet potatoes from seed catalogs are more expensive than those you can buy at a garden center. This is one of the easiest ways to start growing your own.
One more reason to buy slips locally is that the store will have the right type(s) to grow in your area. This is especially important if you live in a place with shorter growing seasons.
When do I plant sweet potatoes?
When planting sweet potato slips (which we’ll talk about next), make sure the soil is at least 70 degrees. In my area, this is 4-6 weeks after my last frost. Most likely, they will be the last thing you plant in your garden. They need 10 hours of sun a day.
They also need a good amount of space. Some types can grow over 25 feet long! If you have room, grow these where they won’t suffocate another plant, or plant them next to tall-growing okra, which also does well in hot weather!
If you don’t have a large space, there are more compact, semi-bush-type varieties you can grow.
A couple of well-known bush varieties are Porto Rico, Vardaman, Jewel, O’Henry, Carolina Bunch, and Georgia Jet. Keep in mind that these will still spill out, but they won’t grow as long as regular sweet potatoes.
Q&A – Is it too late to plant sweet potatoes?
FAQ
How late can I plant sweet potatoes?
What is the latest month to plant potatoes?
Can sweet potatoes be planted in July?