Herbs are very easy to propagate, which means you only need to buy them once for a lifetime’s supply. It’s an easy technique if you know how to do it correctly. I’m going to show you how you can enjoy a never-ending supply of herbs – from a single purchase!
Choosing Herbs to Propagate
Packets of herbs can be bought very cheaply from the grocery store, then rooted them in water or potting mix. When selecting herbs for this purpose, pick the healthiest looking packets and plants. Make sure the sprigs look lush, green and bursting with health. Avoid any herbs that look wilted, or whose leaves are starting to blacken or go brown.
If you’re taking cuttings from garden herbs, make sure to avoid plants that are showing any signs of pests and diseases – check the undersides of the leaves too. And avoid any plant material that’s currently flowering, as you want the cuttings to fully concentrate on root formation. I recommend doing your cuttings in batches so there’s minimal risk of them drying out. If you’re taking cuttings from established plants, do it in the morning when the leafy growth will be at its fullest and firmest before the heat of the day.
Once you’ve taken your cuttings, if you’re not going to prepare them straight away putting them into a sealable plastic bag with damp paper towel to keep them moist.
Preparing Your Herb Cuttings
You’ll need to assemble a few items to help you propagate your herbs:
- Very sharp knife, pruners, or scissors
- Rubbing or isopropyl alcohol to sterilise your cutting tools
- Jars and water, or 3in or 8cm pots and a very free-draining potting mix
Process your cuttings just before you pop them into water or potting mix as the wounds will be fresh – you don’t want them to have started healing over as this will hinder root development.
Start by wiping your cutting blade clean with isopropyl alcohol, then cut just below a node (where the leaves spring from) so the cutting is 4-6in (10-15cm) in length. Cutting just below a leaf gives the best chance of success because that’s where most of the growth hormones are concentrated.
Remove most of the lower leaves, leaving the top two pairs intact. This means the plants will lose less water to evaporation, and will help concentrate the cutting’s energies on root formation. Don’t waste the cut-off leaves – eat them!
Basil and mint are perhaps the quickest herbs to root, and you may see roots within a week in ideal conditions.
Soft-stemmed herbs are best rooted in water. Drop them into a jar then fill with clean mains water so the leaves remain above the water’s surface.
Woody-stemmed herbs such as rosemary and thyme can also be rooted in water, or you can pop them into pots of potting mix. I like to use an all-purpose potting mix or compost for this, to which I add some perlite for additional drainage. (You could use sand instead of perlite.) Water the potting mix before adding your cuttings.
Just as before, cut below a node then strip off the lower leaves. Make hole with a thin stick or chopstick, then push your cutting in. More rigid-stemmed cuttings can be poked in without making a hole first. Position the cuttings towards the edge of the pot, or you could use plug trays and insert one cutting per plug.
Encouraging Root Development
To encourage them to grow you can dip the cuttings into hormone rooting powder to give them a head start, but this isn’t really necessary as they should root soon enough. Incidentally, dipping cuttings in honey also has the effect of sterilising the cut end, which should help it to root better.
Keep your cuttings in a bright position but out of harsh direct sunlight. They will root quicker in the warmth, so you popping them on indoor windowsill can give speedy results.
For herbs propagated in water, check water levels regularly, and top up as required so the bare stems are constantly submerged. The water will get cloudy with time, so change the water every week or so to keep it clear and fresh. Potting mix should be kept damp but not excessively wet. There’s a good chance you may not even have to water at all until the cuttings have rooted.
The first tiny roots can appear as soon as a week after taking your cuttings, but may take a few weeks. You obviously can’t see the roots of cuttings in potting mix, but what you may perhaps notice is fresh new growth above ground – a clear sign that roots have started to grow below ground.
Transplanting Rooted Cuttings
Once they’re rooted, it’s time to pot your cuttings up! Simply remove the rooted cuttings from the water then pot them up individually into 3in (8cm) pots to grow on. I use an all-purpose potting mix for this, again with just a little perlite added for extra drainage.
Make a hole big enough to accommodate all of the roots then feed the soil back in. Gently firm it all in by tapping the pot to settle the potting mix around the roots.
Cuttings rooted in pots can just be teased apart and carefully potted on. Keep the potted-up cuttings moist as they settle into their new home – especially those that have come from water. Keep them out of direct sunlight initially, then harden them off gradually to the full sun, so they don’t collapse with the sudden change in heat and light. If you’re in a hot climate you might want to shade the pots themselves until they are clearly settled in so the roots don’t bake.
Once they’ve grown on a bit, just pinch out the very top growth to help your herbs bush out. These sections can then be used to propagate more herbs – and so the cycle starts once more!
I hope you’re encouraged to grow herbs from cuttings – it’s easy to do, fun and a great way to ensure a truly endless supply! If you’d like to learn more about growing herbs, you might want to check out our book, GrowVeg: The Beginner’s Guide to Easy Vegetable Gardening. There’s loads in there to get your fingers dirty and your belly full of deliciously fresh fruits, vegetables and herbs that you’ve grown yourself.