One of the most common questions we are asked is if we will be getting Sweet Potato “seed potatoes”.
Unlike regular potatoes, which are grown from tubers referred to as "seed potatoes," sweet potatoes are usually grown from slips. The good news is that slips are produced from the sweet potatoes you buy in the shops/market.
A slip is a small plantlet that grows from the sprouts (or "eyes") of a mature sweet potato. These slips can be carefully removed and transplanted into the soil to grow new sweet potato plants.
While it's technically possible to grow sweet potatoes from true seeds (not tubers) they do not produce true-to-type offspring. Growing sweet potatoes from slips is a lot more reliable and efficient.
I have included the below video from the YouTube channel the Millennial Gardener, it’s one of the best I’ve found on the subject of growing your own sweet potatoes from slips. It is well worth a watch if growing your own sweet potatoes is something you want to do. I will also summarise the steps needed to be taken below the video.
Timing
The best time to start growing your own sweet potatoes in Ireland from slips is approx 2 months before your last frost date. Roughly speaking, sometime in February/ March. They can be started later than this, but they may not reach their full potential before frost comes in Autumn.
Choose A Sweet Potato
An older sweet potato that has been stored a long time will produce slips quicker than a newer one. If possible, choose an organic sweet potato. Conventional seed potatoes can be treated with a sprouting inhibitor which helps them store for longer, and could take a lot longer to produce sprouts compared to an organic sweet potato. Select a sweet potato with several eyes, as the sprouts grow out of the eyes.
Planting The Sweet Potato
Oftentimes it is recommended to grow sweet potato slips by placing the sweet potato in a glass of water until it sprouts. However, a better way is to plant the sweet potato on its side in compost. Cover just over half of the sweet potato with compost. Make sure that the eyes of the sweet potato are facing upwards.
Make sure the compost that the sweet potato is in is nice and moist but not waterlogged. Keep it moist the whole time while waiting on the slips to grow.
Wait For Slips
Over the next few weeks, the sweet potato will send out shoots from the eyes. These shoots will eventually grow into slips, which are young plants ready for transplanting.
Transplanting Slips
Once the slips have grown to a suitable size (usually around 15 to 20 cm or 6 to 8 inches), carefully remove them from the sweet potato. Gently separate the slips from each other, being careful not to damage the roots. Each slip can be cut into multiple smaller slips that can all eventually be planted in the ground to create a new sweet potato plant! The above video explains this very well at about the 8 minute mark.
Transplant the slips into individual pots or directly into the spot they are to grow in the garden. Plant them deep enough so that only the top leaves are above the soil. Space the slips about 30 to 45 cm (12 to 18 inches) apart in rows, with rows spaced about 90 cm (3 feet) apart.
Sweet potatoes are heat loving plants. In Ireland, it is best to grow them in a polytunnel or under some other type of protection if possible. At least find the warmest place in your garden if no protection is available to you.
Maintenance
Continue to water and care for your sweet potato plants as they grow. Monitor for pests and diseases. Keep the area they are growing in as weed free as possible.
Harvesting
Sweet potatoes are typically ready to harvest four to six months after planting out, depending on the growing conditions. Carefully dig up the sweet potatoes, being careful not to damage them.
Conclusion
Hopefully you might have found this helpful if growing your own sweet potatoes is something you want to do, and you haven’t done it before, it could be an interesting experiment for this growing season!
Thanks for reading.