BBC Gardeners’ World regular Carol Klein has been busy taking basal cuttings to increase her collection of perennials, including delphiniums, lupins and phlox.

She said that the beauty about basal cuttings is that plants can be cloned exactly in this way, to give a new plant the exact characteristics of its parent, whereas if they are grown from seed they often lose the special traits for which they are valued, reverting to the straight species.

Carol said: “Taking basal cuttings is incredibly easy. You can take them from plants which are really difficult to divide or are grown from seed. The best time to take basal cuttings is from the new growth in spring.”

Carol hopes her new book about propagation, Grow Your Own Garden, will encourage gardeners who have up to now been either too scared or too busy to have a go.

She said: “It’s hugely satisfying.

The very first time you get a cutting to root and then you grow it into a big plant, the feeling is like nothing else.

“You can collect seeds from many plants which will become reasonably true, but if you take basal cuttings it means you get an exact replica of the parent.”

She has taken basal cuttings from many hardy plants as well as dahlia – once the plants have started growing in spring.

“Pot them up, water them well and keep them in a warm place like a greenhouse or warm windowsill which must be bright or the shoots will become long and stringy.

“When the dahlias have made three or four inches of growth, take a sharp knife like a veg knife and push it in between the strong shoot and the crown of plant, cutting without damaging the tuber.”

An older plant should give you a handful of strong cuttings which you should then re-pot, preferably in a clay pot.

“I always put my dahlia cuttings into clay pots because I find they root much more easily because clay’s a natural material, the pots are porous and that earthiness seems to encourage roots to form.”

Evenly space about five cuttings around the edge of a 15cm (5in) pot filled with gritty compost. Carol uses chopsticks to make the hole in the compost to house the cuttings. Plant them in so there’s about an inch of cutting below the surface, then water them well with a fine rose on your watering can.

“Drench the compost so it will settle the compost and cuttings down and make sure there are no air pockets and put them in as warm a place as you have,” she explains.

Some people make little tents for the cuttings out of clear plastic bags, but Carol said if you save a tall punnet from the supermarket you can make a mini greenhouse out of that or use a shower cap to cover them to create an environment to retain moisture.

Just make sure the cover is not in contact with the foliage or it may rot. Heated propagators will probably take a couple of weeks off the rooting time.

“Make sure the foliage doesn’t dry out, so you can spray it with a fine mist from time to time. It will take about a month for the cuttings to root without any bottom heat.”

When roots appear from the hole in the bottom of the pot, re-pot each cutting, knocking them out of the pot carefully and re-potting each one into their own pot.

She said: “You can plant the cuttings later on in the summer or carry on growing them on in pots and they’ll make decent-sized tubers.

When they die down in the autumn, you’ll have a good amount of tuber under the soil.

“If you put the young plants into the garden, be sure to lift them before it gets frosty.

They might flower the first year but I’d take the flowers off because you want the strength to be directed to the tuber under the ground.

“Propagating is enormously exciting, hugely rewarding and each time you do it you re-affirm the primacy of the earth and the plants that grow in it.”

● Grow Your Own Garden, by Carol Klein, is published by BBC Books, priced £20.