How To Propagate Rosemary Plant

Rosemary is a fragrant and delicious culinary herb, well-known by both gardeners and chefs. Knowing how and when to propagate is a budget-friendly way to multiply this plant as much as you want.

The rosemary plants can be propagated at any point during the growing season but the best time to propagate it is in late spring to early summer, before the plant flowers. If you want to overwinter rosemary cuttings indoors, take stem cutting during autumn before frost hits. 

From Cuttings

In most climate conditions, the ideal time to propagate or take cuttings is in late spring and early summer, typically from mid-May to June as this time offers the best conditions for propagation from cuttings. 

Throughout this season, these plants are actively growing, and the new, soft shoots root more readily than older stems. Also, warmer temperature conditions and longer daylight time aid in successful rooting.

From Seeds

The rosemary seeds can be sown indoors anytime throughout the year. However, for outdoor planting, you should wait until the frost risk passes away and soil temperatures increase at least 64°F. This typically occurs in late spring or early summer, together with the ideal time for cuttings.

For Rosemary plants, it takes a longer time in terms of sowing, where the seedlings may well take up to 2 months to appear or maybe 3 months. 

The best method of propagating Rosemary in the soil is by taking cuttings, with mid-May or June being the best time. You should check a healthy-looking plant with lots of new growth.

Rooting rosemary in soil takes a bit longer time than water propagation, but it's fruitful as the cutting roots in pots may not need to get transplanted later on. 

Here are the steps on how you can propagate rosemary plants in soil:

1. Take Stem Cuttings

New tender growth from mature rosemary plant roots most easily. However, semi-hardwood growth is less reliable and takes longer but the cuttings can be rooted. 

Take cuttings 3 to 6 inches in length and cut just below a leaf node using sharp, clean garden shears. Clip the cuttings directly above a leaf node to encourage the mother plant to branch. Then, remove the bottom needles leaving 3 to 5 sets at the top of the stem. 

2. Fill A Container

Several cuttings can be placed in a large container or smaller pots for single stems. Also, propagating several cuttings at a time increases your chances of success. 

Fill the containers with moistened sand or a soulless potting mix and make deep holes in the medium. 

3. Treating With Rooting Hormone

Dip the cut ends of the rosemary stems in water dab them in a dish of rooting hormone powder and shake off any excess. Fill up the small pots with a well-draining potting mix of damp sand and poke narrow planting holes in the substrate with a pencil. 

4. Place The Cuttings In Planting Holes

Insert the cuttings into each planting hole so that the leaves are above the soil line, and then firm the potting mix around the base of each cutting. Gently firm the medium around each stem to keep it upright.

If you are rooting multiple rosemary in the same spot, then space the cuttings at least 3 inches apart.

5. Provide Water, Humidity, And Light

Provide the cuttings with proper watering until they run out the bottom of the pots. Then, place a clear plastic dome or bag over cuttings to boost humidity over cuttings and keep the soil from drying out as fast.

Then these pots are kept under a grow light or on a windowsill that receives indirect light, and regularly water them so that the soil stays damp. 

6. Check For Roots

Rosemary cuttings take about 4 to 8 weeks to root in soil. Any cuttings that turn brown or start dropping leaves during this time aren't rooting and should be composted.

The cuttings are said to be rooted when they grow new leaves and can't easily lift them out of the soil with the fingers. You can either keep the cuttings in their original pots, repot them in large containers, or transplant them to your garden after the last frost date.

A propagated rosemary plant from a cutting in water will mature more quickly than a plant started from seed. A rosemary stem cutting will reach a usable size in just a few months and the new plants that will grow from the cuttings will be an exact copy of the mother plant and have the same flavor, disease resistance, and growth. 

Propating rosemary cuttings in water is very simple. Here are some of the steps to be followed while propagating rosemary cuttings in water:

1. Select Healthy Stems With Fresh Growth

First, select a healthy flowering stem ready to get bloom from your rosemary plant. The selected ones should be 4-6 inches long and have several sets of leaves. Also, look for firm, green stems with new growth emerging at the tip.

2. Take Cuttings

You can use scissors or pruning shears and cut the rosemary stem about 5 to 6 inches back from the fresh-growing tip. Make a clean cut at a 45-degree angle just below a leaf node, further encouraging root growth. 

3. Place The Cuttings 

After cutting, strip off the leaves from the lower 1-2 inches of the steam and prepare the clean glass jar or vase with fresh water at room temperature. Aim for abundant water to submerge the stripped portion of the stem, leaving the upper case dry.

Then, gently place the cuttings with about 1 inch of water, making sure no leaves are sitting below the water line.

4. Change the Water

You need to refresh the water every few days and toss out the cuttings that start to brown or drop leaves, otherwise, they may rot. 

Use a clear glass container to propagate rosemary in water so you can easily keep a record of water level and sprouting roots.

5. Planting Time

The rosemary cuttings should begin to develop roots in about two to six weeks when propagated in water. After the cuttings develop 4 to 6 roots, half inches long, plant the cuttings in a potting mix.

Make sure to keep the cuttings in bright, indirect light and water regularly until they grow properly. 

When the rooted cuttings start to produce new growth, you can continue to grow your new rosemary plant indoors or harden off the plants and transplant them outdoors to your garden. 

The established rosemary after propagation should receive at least six to eight hours of light daily and shouldn't be watered too often and it is prone to rot root. With the proper light, temperature, watering, soil, and fertilizer, these plants can live as long as 30 years. 

Light 

The new rosemary plant should be in full sun for at least 6-8 hours of direct sunlight exposure. If growing indoors, plants require a south-facing window and may also need additional grow lights.

Watering

The rosemary prefers its soil on the drier side. It should be watered every week or two weeks in the ground and once a week. Before watering the plant, check the top inch of soil with the finger, and if it is dry then water the herb. 

Soil

The rosemary thrives in well-draining slightly acidic, loamy soil with a pH value of 6.0-7.0. Also, use a well-draining potting mix formulated for herbs and create your potting soil with perlite or sand for increased drainage. 

Fertilizer

Generally, rosemary grown in the ground will not need fertilizer however, will benefit from light fertilization. Feed the new propagated with slow-release fertilizer or an organic fertilizer in the late winter or early spring.

Also, a balanced diluted liquid fertilizer is applied once or twice during its growing season is enough to thrive. 

Temperature And Humidity

Rosemary likes warm temperatures with moderate humidity. While most varieties tolerate higher temperatures, these plants prefer a range of 55-80 degrees Fahrenheit. 

Pruning And Shaping

Regularly prune your rosemary plant to maintain its shape and promote bushier growth. Pinch off the new growth at the tips to encourage branches and you can have rosemary growing throughout its season. Use sharp shears to make clean cuts just above a leaf node and avoid woody stems. 

Overwintering

In colder climates, rosemary plants might need protection during winter after propagation as the temperature drops below freezing. Bring your rosemary pot indoors to a sun location where bright sunlight is available.

Also, you can insulate the pot outdoors with burlap or mulch until the frost ends.

When it comes to propagating rosemary, you can either keep your cuttings in some fresh water until they develop roots or plant them directly in some sand. While planting cuttings, if you are unaware of the issues due to neglecting any steps, it can hinder the growth of new plants. 

A few missteps can delay your success so you should be aware while processing propagation. Here are some of the possible errors that might happen while propagating:

1. Using The Wrong Stem

Avoid using woody and old stems for propagation to hinder the growth of new rosemary. These stems tend to root slower and lower success rate. Go for younger and greener stems with several sets of leaves for optimal results during the growing season. 

2. Incorrect Cutting Techniques

A clean, sharp cut at a 45-degree angle encourages root growth. Blunt cuts heal slower and may hinder rooting. 

Removing too many leaves from the lower stem reduces the plant's ability to absorb water and nutrients during rooting. Also, aim to strip off leaves from only the bottom 1-2 inches. 

3. Unfavorable Environment

Rosemary thrives in bright, indirect sunlight but the low light levels can lead to weak and leggy growth and hinder root development. If you plant them in excess cold or hot environments, it will hinder growth after propagation as temperatures should be maintained between 65°F and 75°F.

4. Water mismanagement 

Rosemary dislikes soggy roots. Allow the top inch of soil to dry out completely before watering again. Overwatering can lead to root rot and kill the cutting. When propagating in water, refresh the water every 2-3 days to prevent bacterial growth. 

5. Ignoring Root Development

Rooting takes time. Don't hurry to tug or pull all the cuttings to check for the roots otherwise, it will hinder the new growth of plants. Be patient and wait for visible signs of root development before transplanting.

6. Improper Potting Transition 

Ensure your potting mix is well-draining to prevent root rot. Using a mix designed for herbs is ideal. Also, the pot size should be in the correct order size, which means a larger pot can retain excess moisture. Choose wisely a pot slightly bigger than root ball of your propagated rosemary. 

Here are some helpful tips to ensure success while probating your rosemary plant either in soil or water:

• Select a nonflowering stem that is young, green, and actively growing 4-6 inches long with sets of leaves. Avoid woody stems as they root slower. 
• Dipping the cut end of the stem in a rooting hormone powder promotes faster root development, even though it is optional. 
• You can propagate multiple cuttings in the same jar until it has abundant space. 
• During water propagation, use clean and room-temperature water when placing the cutting in the jar. 
• Choose a pot with drainage holes to prevent waterlogging when transplanting your rooted cutting.
• Avoid overwatering as it dislikes soggy roots. You can water when the top inch of soil dries out. 
• Bring your rosemary indoors to a sunny location during winter as the temperatures drop below freezing. 
• Once the plant establishes itself after propagation, pinch off the top leaves to encourage bushier growth. 
• You need to refresh the water every 2-3 days to keep It oxygenated.