Growing Herbs Indoors From Cuttings and Scraps

A supermarket bunch of basil or mint is not just dinner. It is a bag of cuttings. Most soft-stemmed culinary herbs root in a glass of water within two weeks, which means one purchase can become a windowsill supply that keeps producing for months.

Herbs That Root Easily

Soft green stems root fast. Woody stems do not. That single distinction predicts most of your results.

Reliable in water: basil is the star performer, often rooting in seven to ten days. Mint is nearly as fast and almost impossible to fail. Also dependable are oregano, marjoram, lemon balm, sage from soft new growth, and tarragon.

Slower but possible: rosemary and thyme root from cuttings, but they are woody and can take a month or more with a lower success rate. Take several, use soil rather than water, and be patient.

Not worth trying: cilantro, dill, parsley, and chives. These do not root from stem cuttings and must be grown from seed, or in the case of chives, divided. Cilantro and dill in particular bolt quickly and are short-lived regardless.

Choose stems that look fresh and green, not limp or slimy. Supermarket herbs sold with roots attached in a small pot are the easiest starting point of all, since you can simply pot the whole thing up.

Rooting in Water, Then Potting

Cut a four to six inch piece of stem, making the cut just below a node. Strip the leaves from the bottom two inches so nothing sits underwater. Put the cuttings in a jar with an inch or two of room temperature water, in bright indirect light.

Change the water every few days. Stale water rots stems fast, and herb cuttings are less forgiving than pothos.

When roots reach one to two inches, pot up. Do not wait for a huge root mass, because herb roots grown in water are fragile and adapt better when small. Use a small pot, four inches or so, with drainage holes and a well-draining potting mix. Keep the soil evenly moist for the first two weeks, then water normally when the top inch dries.

Light Is the Real Challenge

This is where most indoor herb projects quietly fail. Herbs are sun plants being asked to live in a room, and there is no way around their light requirement.

Penn State Extension is specific: most herbs need 6 hours of direct sunlight. Bay, rosemary, and thyme demand the most, while lemon balm, chives, and cilantro tolerate lower light, needing only two to six hours.

A south-facing window is your best natural option. East and west windows are workable for the lower-light herbs. A north window will not sustain basil, which stretches, pales, and stops producing usable leaves.

If your windows cannot deliver, supplement. Penn State suggests placing herbs 6 to 12 inches from two 40-watt, cool white fluorescent bulbs for 14 to 16 hours. Modern LED grow lights on a timer accomplish the same thing more efficiently. University of Minnesota Extension classifies herbs among plants needing high light and recommends a photoperiod of 12-14 hours daily for herbs grown under lights.

One more small thing that matters: rotate your pots every week or two. Plants on a windowsill lean hard toward the glass, and rotating keeps growth even.

Harvesting Without Weakening the Plant

Cutting herbs correctly makes them bushier. Cutting them wrong makes them leggy and eventually kills them.

• Never take more than a third of the plant at once. The remaining leaves fuel regrowth.
• Cut just above a leaf pair, not in the middle of a bare stem. Two new shoots typically emerge from that point, which is how you build a full plant.
• Take from the top, not the bottom. Pinching growing tips encourages branching, while stripping lower leaves leaves you with a bare stalk.
• Pinch off flower buds as soon as you see them. Once basil flowers, leaf production drops and the flavor turns bitter.
• Harvest regularly. An unharvested herb gets leggy. Frequent light picking keeps it compact.

Container Tips for Edible Plants

Since you are eating these, use containers meant for food or plants rather than repurposed chemical containers. Any pot needs a drainage hole, since standing water is the leading cause of dead indoor herbs. Penn State recommends growing herbs in containers with a drainage hole and in a potting mix that will aid water drainage.

Wash the pot before use, use fresh potting mix rather than garden soil, and give deep-rooted herbs like dill a taller container. Finally, rinse anything you harvest before it goes in the pan.