How to Propagate Herbs From Cuttings in Water

Which Herbs Root in Water

To propagate herbs in water, cut a 2 to 4 inch stem tip just below a leaf, strip the leaves from the lower half, and stand it in a jar of room temperature water in bright, indirect light. Change the water about once a week. Roots usually show within two to four weeks, and the cutting is ready for a pot when they are 1 to 2 inches long.

The method suits soft-stemmed herbs best. Montana State University Extension groups culinary herbs with the non-woody plants that “tend to root quickly and reliably in either water or a soilless medium.” Penn State Extension says of basil that cuttings are easily rooted in water, and the Royal Horticultural Society describes the same jar method for it. Mint is another natural candidate, since University of Maryland Extension lists stem and stolon cuttings as a standard way to multiply both peppermint and spearmint.

Woody herbs are a different case. Purdue’s consumer horticulture program lists basil, oregano, lavender, rosemary, thyme and sage as herbs that root easily from shoot tip cuttings, but its instructions put those cuttings into moist soil mix, vermiculite or perlite. The extension guides for rosemary do the same.

Herb	Stem type	What the sources say
Basil	Soft	Roots easily in water; pot after a few weeks
Mint	Soft	Propagated from stem or stolon cuttings
Oregano	Soft to semi-woody	Roots easily from shoot tip cuttings
Rosemary	Woody	3 to 5 inch tips root in a well-drained soilless mix in 4 to 6 weeks
Thyme, sage, lavender	Woody	Root easily from shoot tips set in moist media

One healthy plant can supply several cuttings, which is often cheaper than buying seeds or starter plants. It is also a simple way to carry a favorite basil through the year, because a new cutting can be rooted before the parent plant bolts.

Taking the Cutting

Choose a healthy shoot that is not flowering. The Royal Horticultural Society’s instruction for basil is to snip off a non-flowering shoot just below a leaf, remove the lower leaves and pinch out the tip. It treats these as softwood cuttings taken during summer.

Cut at a node, the point where leaves join the stem. Purdue explains that root formation is more abundant there. Iowa State University Extension recommends a 2 to 4 inch stem tip, taken with a clean, sharp knife, with the leaves removed from the lower half. For rosemary, NC State Extension advises a slightly longer tip of 3 to 5 inches, stripped so that only the top 1 to 2 inches of stem still carries leaves.

Bare stem below the waterline matters as much as the length. Montana State University Extension says to remove the lower leaves so they do not rot in the water.

How to Root Herb Cuttings in Water, Step by Step

1. Cut a 2 to 4 inch tip from a non-flowering shoot, just below a leaf node.
2. Remove the leaves from the lower half of the stem. For basil, pinch out the growing tip as well.
3. Stand the cutting in a jar of room temperature tap water with at least one node submerged and all remaining leaves above the surface.
4. Set the jar in bright, indirect light. A kitchen windowsill out of direct sun works.
5. Change the water weekly, and sooner if it turns cloudy.
6. Pot the cutting when the roots are 1 to 2 inches long.

Clear glass lets you watch the roots, but it is not required. Montana State University Extension points out that an opaque jar or vase helps the roots stay dark while light on the leaves supplies the energy for root growth. The same guide says not to add fertilizer to the water, because the carbohydrates stored in the stem are enough to build roots.

Water Changes and How Long Roots Take

The extension guides agree on fresh water and differ slightly on the schedule. Montana State says to change it weekly. Iowa State says one to two times each week, and adds that the water level should never drop far enough to expose developing roots to air. University of Vermont Extension gives a simpler trigger: if the water begins to turn cloudy, replace it with fresh room temperature water.

For timing, Montana State’s figure for non-woody cuttings in water is that roots typically develop within two to four weeks, depending on the species. The Royal Horticultural Society says a basil cutting will quickly form roots and can be planted in a pot after just a few weeks. Vermont’s guide is a useful reminder for slow jars: rooting can take days or weeks, sometimes months, and a cutting that still looks healthy is worth waiting on.

Rosemary shows how much slower woody stems are. NC State’s 4 to 6 week figure is for cuttings in a pot of well-drained soilless mix, the medium the guide recommends, and it expects only 30 to 50 percent of those cuttings to root.

Potting Up Water-Rooted Cuttings

Move the cutting to a pot when the roots are 1 to 2 inches long, which is the point Montana State gives for reducing transplant shock. Iowa State puts it at about 1 inch. Both guides pot the cutting while the roots are still short.

The reason is the roots themselves. Iowa State notes that roots formed in a glass of water are more coarse in texture and are not well adapted to potting soil. After potting, a water-rooted cutting may show stress such as wilting, leaf drop, browning leaves or tip die-back. Consistent care helps it recover, so plant into moist potting mix and keep the mix evenly moist while new roots grow.

For a rooted mint cutting, give it a pot of its own. Mint spreads by runners, and University of Maryland Extension suggests trimming any that creep over the rim before they root on the other side. Our guide to the right pot for mint covers container size.

Troubleshooting Cuttings That Fail

A stem that turns soft and dark at the base is rotting. Check for leaves below the waterline first, then look at the water. Cloudy water is the signal to replace it, and a jar that has gone a full week unchanged is past due.

If a cutting stays green but shows no roots after four weeks, look at where it sits. The guides call for room temperature water and bright, indirect light, so a cold sill or a dim corner slows things down. Flowering shoots are a poor choice as well, which is why the basil instructions specify a non-flowering one.

For rosemary, thyme, sage and lavender that stall in a jar, switch to the method the extension guides describe: set shoot tips (3 to 5 inches long for rosemary) in moist soil mix, vermiculite or perlite, cover the container with plastic to hold humidity, and keep it warm and shaded.