Fancy growing a highly nutritious, wonderfully versatile, decidedly delicious, food crop and have a patch of garden ground going spare? Then sweet potatoes may be the crop for you.

Growing this useful root crop is far easier than struggling to grow ordinary potatoes and harvests can be huge — especially in locations such as Karachi where sweet potatoes happily grow all year round.

Ipomoea batatas, as sweet potatoes are botanically known, are sun-loving plants with origins in South America. They also are — as some of you may already have guessed from the Ipomoea part of their name — members of that huge family group which also includes the loved (by flower gardeners) or hated (by farmers) Morning Glory vine, which is guilty of strangling other plants to death unless kept under iron-clad control.

Growing sweet potatoes is as easy as ABC

A major difference between these two plants is that sweet potato vines spread at the ground level, rooting as they go, while morning glory vines climb up just about anything and everything they can possibly get a tendril around.

Starting off a sweet potato patch is a very simple task indeed. Since they love sunlight, select a spot that receives at least six hours of direct sunshine every day.

They are not especially fussy about soil but prefer light — on the sandy side — soil to heavier types. They flourish in sandy soils but while they will grow in clay ones they will not do all that well unless you work at lightening it up by adding sand, organic compost /manure.

Soil, whatever the type, should contain a reasonable amount of nutrients — organic compost and manure are the best options. However, be careful not to add too much as sweet potatoes will produce large amounts of strikingly healthy leaves but, but not the more-important tubers in extremely rich soil. Being rebellious runaways, the vines also need lots of space to spread.

THE WHERE, WHEN AND HOW

Tubers can be planted at any time of the year in Karachi, in coastal regions and in much of the plains but only during spring in areas that experience severe winter cold.

Buy medium-sized tubers from the bazaar and plant them in ‘light’ soil — about three feet apart, four to six inches deep, in rows three feet to four feet apart. Keep them lightly watered and they will germinate in no time at all. Before you know it, the plant will have grown all over the place, at the speed of light. In places where soil is on the heavy side, plant your sweet potatoes on either mounds or in raised beds.

They can also be propagated from cuttings — better known as ‘slips’ — taken in very early spring. Slips, between one and two feet long, can be taken from existing plants or be specially produced by half burying a tuber (the upper half sticking out) in a pot of freely draining, sandy soil which is then watered, just once, sealed inside a plastic bag to maintain temperature and humidity. These will, quite quickly, send out a number of shoots that, when long enough, can be used as slips.

Slips are planted at the same distance apart as tubers: remove all except for three to four leaves at the tip of each slip, insert the cut base of a slip carefully (they are brittle) into the ground to a depth of three to four inches and then lay the remaining length of the slip on the soil surface. Pegging it — using bent pieces of wire is ideal — into the soil every two to three inches along its length and where there are lead nodes (those from which you removed leaves).

The slips will root at the cut base and then, all going well, from each leaf node too and then watch out. Jack and his beanstalk have nothing on the rate at which sweet potato vines can grow!

The hotter the weather, the faster these vines race, rooting as they go and, as tubers develop from roots; there should be lots and lots of tubers to come.

From planting — be this from tubers or slips — to harvesting, can take as little as four months over the summer and perhaps six months over the winter, all depending on the localised climate.

Sweet potatoes enjoy a drink during dry spells but do not need watering on a daily basis: too much water can cause the tubers to rot and we certainly don’t want that to happen!

The batata’s bitter and sweet sides

From personal experience, when harvesting sweet potatoes, there are always those that manage to hide and which, left to their own devices, will continue to grow and produce the next crop.

As they can’t be stored as long as ordinary potatoes can be once harvested, instead of digging them all up at once, digging up a few every now and then is a sensible routine to follow. This will also help ensure that you have fresh supplies all the year round.

The biggest problem with these ground-covering, weed-suppressing vines is that, if you don’t keep them firmly under control, they have a tendency to make a complete take-over bid and will, if your back is turned for a very short time, subjugate every other plant around.

Before I forget, sweet potato tubers can be red, white or yellow and all are equally delicious. The stems and leaves too are 100 percent edible and they make a fantastic panache salad. So go on, find a spot and start planting this incredibly bountiful crop. It’s worth the effort: I promise!

Please continue sending your gardening queries to zahrahnasir@hotmail.com. Remember to include your location. The writer does not respond directly by email. Emails with attachments will not be opened.

Published in Dawn, Sunday Magazine, January 29th, 2017