There is nothing nicer than getting plants for free. One of the quickest ways to do that is to take cuttings -- this applies particularly to perennial herbs. Taking cuttings is one of the most reliable methods of propagation and it is also fun -- there is such a sense of satisfaction when the cutting begins to grow.

All you need is a clean knife or a pair of secateurs and as soon as the cutting has been taken, insert it in a damp growing medium, which can be well drained compost or a mixture of peat and sand. Warmth is needed for rooting and humidity is important for leafy cuttings. To create a mini greenhouse you can enclose the pot in a plastic bag.
Here’s the step-by-step approach to taking softwood cuttings that I use in my home study course, ‘How to be a wildly successful herb gardener’.

• The first step is to take a cutting with at least three leaves and a shoot. The best stems for cutting are the side branches or those near the base of the plant. Trim the stem just below the lowest leaf point• Have a clean pot on hand that is filled with damp, but well-drained compost. Make a hole with a dibbler or your finger, and insert the cutting.
• Gently firm the compost by pressing downwards and sideways towards the cutting (Picture 6 and 7).
• Water lightly
• Bend a piece of wire to form an arch over the cutting and press it into the pot. Cover with a transparent polythene bag. Another option is to cut the bottom off a 2-litre soft drink bottle and place it over the pot
• Place the cuttings in a warm area that receives good light but no direct sun
• The plastic bag or bottle traps the moisture and the heat inside, creating a mini-micro climate allowing the pot to be left for about 3 days without watering. Check every now and then to ensure that the soil is still damp.
• If it gets too humid in the bags it might be necessary to open them up during the day otherwise fungus could attack the plants.
Softwood cuttings should root within two to five weeks. Such cuttings are generally taken in spring and summer.
The cuttings taken in late summer or early autumn are usually from ‘half ripe’ wood. They will be firmer than softwood cuttings and should be taken from the side shoots of the current season’s growth. It is possible to put these cuttings straight into well-prepared soil but the soil must be kept moist and they must be kept shaded.
The best time or times to take cuttings, and the type of cutting to be taken during that season, varies from herb to herb.

The following guide should be helpful:

Spring

Bergamot (MONARDA didyma) -- root cuttings.
Catnip (NEPETA cataria) -- softwood cuttings (late spring). Divide plants every three years.
Horseradish (AMORICA rusticana) -- root cuttings.
Lemon balm (MELISSA officinalis) -- stem cuttings.
Lemon verbena (ALOYSIA triphylla) -- softwood cuttings (late spring).
Rosemary (ROSMARINUS officinalis) -- softwood cuttings (late spring).

Summer

The Artemisias: Wilde als (ARTEMISIA affra);
Mugwort (A. vulgaris);
Southernwood (A. abrotanum);
Wormwood (A. absinthium) -- take semi-hardwood cuttings in late summer.
Bergamot (MONARDA didyma) -- stem cuttings.
Feverfew (TANACETUM parthenium) -- stem cuttings.
Mints -- stem cuttings.
Sage (SALVIA officinalis) -softwood cuttings in late summer. Replace plants every four to five years.
Santolina (SANTOLINA chamaecyparissus) -cuttings, from midsummer to autumn.
Savory (SATUREJA montana) -- stem cuttings.

Spring and summer

Marjoram (ORIGANUM majorana) -- stem cuttings (late spring to summer).
Oregano (ORIGANUM vulgare) -- stem cuttings (late spring to summer).
Scented geraniums (Pelargonium species) -- tip cuttings (spring and late summer).
Thyme (all Thymus species) -stem cuttings.