Saturday, February 27, 2010

Nurserymans Tip to Growing Sweet Potato

Nurseryman's Tip

Sweet Potato.

Full Name: Ipomoea batatas ‘Beauregard’
Leaf: Heart shaped, green
Preferred Location: In the soil/big growing containers
Likes: Well drained, sandy soil/Full sun
Dislikes: Over watering and temperatures below 5°C

Sweet potatoes are becoming increasingly popular as part of a healthy diet in Europe. Home
production of Sweet potato can be done in big plastic containers, on the patio and therefore
makes the crop available for a wider range of gardeners. This crop is especially interesting for
younger people or those without a large garden who want to grow something special. Anyone who has traveled to countries like USA, Australia, Middle East and many of the Pacific Islands where Sweet potato is a common vegetable. The dietary and health advantages of Sweet potato are now well recognised and Sweet Potato is commonly recommended by dieticians for very young babies beginning their solid food diets.

In 2009 I posted this blog piece showing ourtrials on Sweet Potato. You can see this post here

I have put together the following detailed tips for your information in growing and storing your own SweetPotato this year.

Growing instructions
- Optimum of 4 - 5 months of continuous growing between 10°C night and 30°C day required
- ‘tuber’ growth starts during the shortening days
- Well draining, sandy soils, pH 6 to 6.5, minimum 20 to 30 cm deep
- Planting of the rooted cuttings in rows 1 m apart, 30 cm within the
rows or in individual growing containers
- Water in when planting the rooted cuttings, but overwatering during
the growing period can cause root damage
- Requires less fertilizer than most vegetable crops so do not overfeed
- Keep weed free during growing
- Relatively free of pest and disease problems, but can have root rots caused
by cold and wet soil conditions
- Harvest in dry weather where possible
- Harvest before the first frost and with care as sweet potatoes are sensitive to bruising
- Store the roots by over 25 °C and a minimum relative humidity of 90% for 2 weeks to heal
the wounds, reduce weight loss and convert the starches into sugars
- Savour the Sweet potatoes boiled, mashed or fried accompanied by a nice glass of chilled white wine

Nutrition information
Sweet potatoes are :
- fat-free and cholesterol-free
- have only 130 calories per serving (one medium
- are a good source of fibre – 3.9 grams
- are an excellent source of:
Vitamin A – 7860 IU/serving
Vitamin C – 29.51 mg/serving
Potassium – 265.2 mg/serving
Calcium – 28.6 mg/serving
Iron – 0.79 mg/serving
Folate – 18.2 mcg/serving

Special notes on harvesting & storage of sweet potato.

It is desireable to leave your crop of Sweet Potato for as long as possible before digging out. The top growth will not die back like the normal potato unless it is hit by frost. I recommend you target to harvest some time end of September if growing out door and mid October if growing in a greenhouse. It is important that they be harvested befroe grond temperatures go too low and certainly before any early frosts.
When harvesting Sweet Potato it is desireable to have dry soil conditions. If this isnt possible take special care to lay the roots out in a dry warm location. Sweet Potato have a very thin skin so care should be taken not to bruise or cut the skin surface as this can lead to rots during storage or curing the potatoes.


For best it is desireable to cure sweet potato after harvest. Curing brings out the best in flavour. Proper curing has been shown to increase the sensation of moistness and sweetness, enhance the aroma, and decrease starch content while increasing sugars. Curing also drys up any skin damage and prevents rots in storage. Curing also helps harden or set the skin which helps prolong storage. An idea temperature for curing is between 25 C and 29 C with humidity of 85% which helps avoid weight loss.


Ideally cure the tubers for at least a week you can then store the tubers between 10 Celcius to 13 Celcius for over 6 months. Ensure the tubers are stored at a reasonable humidity 80% to 85% is perfect but good air circulation should be maintained by storing in layers. Do not the potatoes storage environment to become excessively dry or weight loss can occur. It is also important not to allow storage temperatures rise too high as sprouting will begin at about 15 Celcius or 16 Celcius.


  1. This is great thanks. I was asked about sweet potatoes at a workshop recently. The lady was asking where you could buy tubers/slips. Any ideas?

  2. Hello Dee,if you send an email to me letting me know how many and when you want them I will get you sorted with some. I have set up mail order and garden distribution for them and I will be sending plants out to these customers in early April. SO Sir Walter Raleigh move over MyPlant brings Sweet Potato to Ireland wide spread :) .

  3. This comment has been removed by a blog administrator.


Please leave us a message