7 pointers for growing sweet potatoes and potatoes

Growing sweet potatoes and potatoes isn't that hard when you follow these simple and useful pointers.

Related to the morning glory, the sweet potato is a tropical vine that performs best in regions with long, hot summers and makes a fine summer ground cover; some are grown strictly as ornamentals.

• Grown from slips, or rooted sprouts, sweet potatoes develop best in sandy loam and need full sun and about 120 days of warm temperatures.

• Push soil to about 30 centimetres high and 30 centimetres wide—sweet potatoes will appreciate the good drainage.
• Plant the slips 10 centimetres deep at 40-centimetre  intervals and keep them moist for several days.
• Sweet potato slips are usually planted in hot weather, so it helps to cover them with a box or flowerpot to shield them from strong sun for a few days after planting.

With either edible or ornamental sweet potatoes, you can increase your supply by snipping off 15-centimetres stem tips and rooting them in moist potting soil.

After digging sweet potatoes, cure them in a warm—29°C—place for seven to 10 days.

• This curing period helps to toughen the skins and makes the tubers taste sweeter.
• After curing, switch your tubers to a cooler spot where temperatures are between 13°C and 18°C. They will keep for four to five months.

Grow what you can't buy, such as little potatoes with buttery yellow flesh or oblong "fingerling" types. Blue potatoes are fun to grow, too, such as the "All Blue" variety, or try "Caribe," which has snowy white flesh beneath purple skins.

• Plant early, two to three weeks before your last expected frost, while the soil is still chilly.
• When leaves and stems appear, start mulching to keep the soil cool and moist.
• Potatoes stop growing new tubers when the soil gets warm, so it's best to help them get a fast start in spring.

Light turns potatoes green and causes solanine, a mildly toxic substance that tastes bitter, to develop.

• As plants grow, keep mounding soil or mulch up around them to prevent sun from reaching the tubers, some of which are just below the soil surface.
• Wait for a cloudy day to harvest so your potatoes won't be exposed to bright light.

True new potatoes are small potatoes gathered while the plants are still green.

• Carefully pull back the mulch, feel around for a few treasures and put the mulch back in place after you've gathered your dinner potatoes.
• The plants won't even notice they're gone. Harvest the rest of your crop when the plants begin to die back naturally.

Fat, reddish bugs chewing potato leaves and flowers are the larvae of Colorado potato beetles.

• Pick them off, spray them with a neem-based insecticide or better yet, nab them before they hatch.
• Check leaf undersides for clusters of yellow eggs and pinch off the egg-bearing leaves.