Let’s Plant Some Herbs – Propagation

Seeding is our favorite form of propagation. A seed is a repository for all the genetic diversity of the ancient wildness of these potent medicinals. When you are looking for medicine in a herb, you want to use the purest, strongest strain of the species you can get; in other words, you want the original, unchanged, wildest form available. So you will not, in most cases, choose a hybrid, which is indicated by a multiplication sign between a plant’s genus and species name or by a proper name within single quotes, like ‘Jenny’. And you won’t choose varieties developed for a wide array of flower colors or disease resistance. Seeds of unselected, wilder species will give you the full range of biodiversity possible for the herb – which makes it perfect for use as herbal medicine.

Most of the herbs featured in this website can be easily sown from seed. You will find instructions for the propagation methods {stem cuttings, root cuttings, root division, and layering} within this article. Our favorite seed sources are listed in the page ‘Buying and Ordering Plants’. We recommend that you seek out certified organic sources or get to know the seed company’s practices personally. We support small, local seed exchanges and regional seed houses whose activities are transparent, and we avoid those that trade in genetically modified or engineered seeds or plants.

Starting Seeds:

There are a few herbs that germinate best when they are seeded directly in the garden. However, most get a better start when sown indoors or in a greenhouse. You can start seeds in purchased seed trays or flats, recycled plastic nursery pots, or just about anything you have available that’s an appropriate size and shape: egg cartons, half clamshells, or paper cups, for example. If you can, start seeds in containers with individual cells. That way, when it’s time to transplant, you won’t have to disturb the seedlings’ roots as much as you would while separating seedlings started in a large container.

Seed-Starting Mix Recipes:

You can purchase an organic seed-starting mix at most hardware or garden stores, or you can make your own. Here are a few sample recipes.

Seed-Starting Mix 1

1 part organic potting soil

1 part perlite or vermiculite

Seed-Starting Mix 2

1 part garden soil

1 part well-sifted organic compost

2 parts horticultural sand or a combination of sand, perlite, vermiculite, and coir

Seed-Starting Mix 3

1 part well-sifted organic compost

1 part perlite or vermiculite

1 part coir

How to Plant Seeds:

Follow these instructions for sowing and nurturing your newly planted seeds.

  1. Make sure your mixture is moist but not soggy. Fill your clean, disinfected containers with the mix, and lightly tamp it down to settle and firm it.
  2. Make a shallow indentation with your finger or a pencil or chopstick and drop several seeds. Unless you’re planning a huge garden, do not sow all of the seeds in a packet; save some for a second sowing or the next season. In most cases, the average individual or family will only need 5 to 20 plants of a particular herb.
  3. Cover the seeds lightly with the seed-starting mix to a depth of two to three times the diameter of the seed. Very small seeds will get just the barest cover or will be pressed into the soil surface.
  4. Water or mist the flat or container gently, label it with the name of the herb and the date and place it in a warm location. If you are starting seeds early in the spring and the seeds need warm soil to germinate, you may want to purchase heating cables or pads {available online} or place the containers near a radiator or heater. A bright east- or west- facing windowsill with indirect light can suffice for germination. Most seeds germinate best between 60 and 80 degrees F.
  5. Label each herb container or tray with the herb name and the date. Keep the seedlings gently watered or misted so they remain moist but not soggy. {And if you will be gone for the better part of each day, cover the containers or trays with sheets of plastic wrap or plastic bags to keep in warmth and moisture. Once the seeds have germinated, remove the covering.} Make sure new emerging seedlings get 6 hours of sunlight daily. If they do not, you will need to supplement with fluorescent, LED, or grow lights. Germination times vary from several days to several weeks.
  6. The first leaves that emerge with germination {called the cotyledons} will be followed by the “true leaves,” which will look more like the mature leaves of the herb. You can transplant a plant to its own container or an outdoor bed after the true leaves have appeared, but it’s best to wait until there are several sets of true leaves and the plant looks healthy and strong.

Transplanting Outdoors:

If you are starting seeds indoors, sow them 4 to 6 weeks before the last spring frost date in your area. Once the frost date has passed, you can safely transplant seedlings into outdoor pots or beds.

As you notice that the young plants are ready, take them outdoors in their seed-starting trays or containers for a few days, and bring them back inside before nightfall. This process is called “hardening off,” and it helps the plants become used to the temperatures and conditions outside. After several days of hardening off, leave the plants outside overnight. Then transplant them into beds or containers, preferably in the late afternoon or on a cool day. If they are going into the ground, dig a hole bigger than the seedling and place a handful of compost or aged manure at the bottom. Place the seedling into the depression and firm the soil around it, burying the main stem slightly deeper than it had been growing in the seed-starting medium. Water it gently.

Stem Cutting:

If you have access to a mature plant of the species you would like to grow, in many cases, you can propagate by stem cuttings. Cuttings will result in a new plant in a matter of weeks, and you’ll have a success rate of 50 to 90 percent, depending on the herb. Cuttings are best taken in spring or early summer.

Here is how to propagate from stem cuttings.

  1. Make a mixture of 1 part sand and 1 part perlite, or 1 part sand and 1 part moistened coir, with an optional smattering of compost tossed into the mix, and moisten it until it is wet but not soggy. This will be your rooting medium.
  2. Fill clean, sterilized pots with the mixture, leaving an inch or so at the rim of the pot. Use your little finger, a pencil, or a chopstick to poke a 2-inch-deep hole in the mix for each cutting you will be starting.
  3. Snip a 4- to 6- inch section of a healthy stem, and remove all leaves from the bottom one-third to one-half of the cutting, leaving the only naked stem on that portion. You may also pinch off the tiny tip of the cutting.
  4. As an option, you can dip the lower half of the stem cutting into rooting hormone or a strong tea made from willow bark or twigs. Insert the cutting into the hole you have poked in the rooting medium. Make sure the area you stripped of leaves is below the soil.
  5. Check the moisture level of the rooting medium once or twice daily. You can also place a plastic bag over the stem cutting, making sure it doesn’t touch the leaves. {Insert a bent coat hanger, chopstick, or another support around and above the cutting.} Then cut slits in the bag to allow fresh air to reach the plant.
  6. Place the cutting in the bright but indirect light. If the air temperature is going to fall below 65 degrees F, consider adding bottom heat {in the form of heating coils or pads} for greater success.
  7. Stem cuttings will form roots in 2 to 4 weeks. After 2 weeks, check to see if the cutting has rooted by gently tugging on its top leaves to see if there is resistance, which is a sign that roots have formed.
  8. As soon as possible after you verify that the cutting has rooted, transplant the seedling into a pot or its permanent location in the ground.

In the fall, you can take hardwood cuttings from woody plants during their dormant period. Mid-autumn id often the best time to collect and plant cuttings, because the plants will have time to form roots before buds begin to grow.

  1. Make a mixture of 1 part sand and 1 part perlite, or 1 part sand and 1 part moistened coir, with an optional smattering of compost tossed into the mix, and moisten it until it is wet but not soggy. This will be your rooting medium.
  2. Fill clean, sterilized pots with the mixture, leaving an inch or so at the rim of the pot.
  3. Collect 4- to 8- inch cuttings from vigorous, 1-year-old wood, a few inches below the tip of the branch or stem. Make a sloping cut at each tip, slightly above a bud, and a straight cut at each base, slightly below the bud.
  4. Place the cuttings 2 to 4 inches apart in the medium, with the top bud of each about 1 inch above the rooting medium’s surface. Be sure the cuttings point upward, and double-check that you have stuck the ends with straight cuts into the medium.
  5. Place the cuttings {along with their rooting medium mixture} in a “nursery” trench that you have dug in the ground soon after you harvest them from the mother plant. This trench will allow them to overwinter before they are planted individually in the ground. Cover the cuttings with 6 to 8 inches of mulch.
  6. Keep the cuttings moist over the winter. Remove the mulch and move your rooted cuttings to their new homes in the spring.

Root Cuttings:

Plants that have taproots {like carrots} are best divided by actually taking slices from the root of the mature plant. This method also works well for plants that have long, creeping roots, rhizomes {underground stems with a root-like appearance} or runners.

  1. Dig the root carefully and gently brush off any excess soil.
  2. If the plant has a taproot, cut off 1-inch slices. If you have a thin creeping rhizome, notice the growing nodes {bumps or lines on the root} and divide the rhizome into sections that each has at least two of these nodes.
  3. Using the same potting mix that you would for stem cuttings, fill a pot one-half to two-thirds full. Lay the taproot or thin root sections on the surface and cover it with more potting mix, to just below the rim of the pot. Do not compress the soil.
  4. Label your new starts and water them well.
  5. When you notice a new plant emerging from the soil surface, you can transplant it into its permanent home.

Root Division:

Sometimes the best way to gain a new plant is to take advantage of someone else’s excess! There are quite a few plants that expand and spread by runners {underground stems} and others that self-seed profusely and form massive plantings. These can be lifted out of the soil and divided, and the resulting sections can be replanted. The same process can renew an older plant that has died out in the center. It’s done with perennial herbs that have fibrous roots {as distinguished from taproots} anytime during the growing season, but is perhaps best done in the fall, when the plants are beginning to die back, or in the early spring, when growth is starting to explode. Of course, check the individual herb to make sure that the herb you are working with is suited to this technique.

  1. Carefully dig and lift up the whole plant, making sure to get as much of the rootball as you possibly can. If the plant is large or unwieldy, you may want to prune it to a manageable size first.
  2. Shake off any excess soil and gently tease the root mass apart, sensing where it most easily wants to separate.
  3. If the root is large, hard to separate, or very dense, you can use a weeding tool, a digging fork, or even clippers or scissors to separate the roots.
  4. Replant all sections immediately, either into pots or in the garden. If the herb likes a richer soil, fill the new holes with compost to give the divisions some nutrition for the journey to maturity.
  5. If you haven’t already, prune the above-ground portions by at least half so that the newly disturbed roots won’t have to feed as much plant matter.
  6. Water thoroughly.

You can also use the same technique to separate offsets and side shoots from parent plants. Remove younger, smaller shoots from the outer edges of a rootball by breaking or cutting them off, making sure that each piece you remove has its own root system. Replant the offshoots immediately to the same depth as the original plant, and water it thoroughly.

Layering:

This is the oldest method of propagation, and it’s one that happens naturally as certain herbs age. The long, leggy stems of some plants droop down and rest on the soil, and when they touch at a node {a raised area on the stem where the leaf attaches}, roots will form. You can mimic this process by layering selected plants to create offspring.

  1. Choose a strong, healthy stem, and notice where it will easily dip to the earth. Remove all the side shoots and leaves from a 6- to 12- inch section at the point of soil contact.
  2. If you wish, you may use a knife to gently scrape the underside and outer woody portion of the stem for 1 to 2 inches at the point of soil contact.
  3. Fluff or rough up the soil where you plan to bring the stem into contact with it, mixing in a thin layer of compost or watering with liquid fertilizer.
  4. Press the stem to the earth. Anchor the stem with a stake, a U-shaped piece of wire, a stone, or something similar. Mound a layer of soil over the anchored section of the stem.
  5. Keep the area moist. Layering is a long process, but if you start in the spring, you should be able to separate your new plant in the fall.
  6. When roots form, snip off the portion that connects the new plant to the mother plant. Pot up the new plant immediately. If it’s going into the ground, transplant it in the fall, or keep it in a sheltered spot and wait until the following spring.

You can use this same technique to layer potted plants, too. Pull a runner or a long stem from the mother plant, and set it on top of the soil of a new pot. Make sure it is secure, as directed above. When it roots, you have a new potted herb already nestled in.

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Propagating Herbs

Plants can be propagated by four fundamental means. They can be propagated by their seeds, grown from root divisions, stem cuttings as well as layering. In order to undertake any of these techniques successfully, it would be prudent if you start by studying the attributes as well as the growth patterns of the particular plant you wish to proliferate. Gaining more and more knowledge about the habits of a plant will help you to propagate the plant more easily.

Growing from seed

Plants produce copious seeds that are vigorous and live for a long period. Naturally, the seeds are driven out of the plants by the force generated when the seedpods split open. Subsequently, they are transported far and wide by sticking to the hairs on the animal hide or under the bellies of birds or by the wind and they land in a new place far away from their original home. In fact, it is possible to sow a number of seeds immediately when they are collected from the fruits enclosing them. On the other hand, some seeds remain dormant for a while prior to becoming feasible as well as ready for germination.

Again there are other seeds that require stratification to facilitate maturing and become feasible for sowing and germination. In fact, when seeds are stratified, they are kept in cold temperatures which they would generally go through in nature during their dormant period in the winter months. Seeds that need to be stratified should be cleaned of dust, soil, and impurities and drenched in water for anything between 24 hours and 49 hours. Subsequently, they need to be packed in any damp medium like sphagnum or sawdust and stored in the refrigerator for a period roughly between one and four months, subject to the species. There are a number of seeds that have further complicated dormancy prerequisites and simply keeping them in cold temperature for any period of time is not sufficient. They require being alternately kept in warm, cold and again warm temperatures.

There is a third type of seeds that are dormant for a considerable period owing to their tough seed coat, which stops moisture from going through till they are notched or lacerated. A section of horticulturists employs a little file to make scratches on the seed coat or to put these seeds in simmering water with a view to make them soft. Soaking seeds in warm water actually make them livelier and makes them ready for germination.

It has been seen that the majority types of seeds germinate most excellently when sown in a neutral soil medium that is porous in nature. However, some plants, for instance, rhododendrons have a preference for acidic soil for germinating, but these types of plants are certainly among the exceptions. Several substances including sand, perlite (a product from volcanoes), sphagnum moss (obtained from swamps), vermiculite (also called expanded mica), pounded granite as well as uncontaminated soil are utilized in the form of germination mediums. You should ensure that the medium is not very weighty and, at the same time, sufficiently substantial to enable the seedlings to grow up straight, while their roots hold on to the soil steadfastly. Using a mixture of equal proportions of crushed granite and sphagnum moss is an excellent medium to start with. In fact, many people prefer to use sphagnum moss as a starting mix, as this substance is extremely resilient to invasion by fungi, which generally weaken and deteriorate the seeds as well as the cuttings. Ideally, you ought to sow the seeds in rows maintaining a space of no less than one inch between them. A common guideline to decide on how deep the seeds need to be sown in the soil says that usually the seeds should be sown up to a depth that is equivalent to their vertical measurement.

Much before you sow the seeds, you need to keep watering the growing medium. Keep the flat in a temperate place, about 70°F. You should keep spraying the seeds many times every day till they begin to germinate. When they start germinating, examine the seedlings closely to detect if there are any fungal diseases. In case you find that the plants have been damaged, prick them out cautiously and annihilate them. Generally, biodynamic gardeners (people who grow plants organically) mist chamomile tea on the germinating plants with a view to avoiding damping off. This herbal tea is prepared by infusing the herb chamomile in water for a couple of days or even more. It is advisable that you apply the spray in the form of a mist with a view to preventing any further damage to the seedlings.

Besides developing damping-off fungus, the major threats to the germinating seeds include allowing the growing medium to become parched and not maintaining a sufficiently warm temperature. Provided you are watchful and succeed in preventing the occurrence of these conditions, you will be able to produce several healthy seedlings, thereby helping nature.

It is worth mentioning here that biodynamic gardeners often bathe the seeds with special preparations based on herbs. People who advocate this method say that when you spray the seeds with diluted solutions prepared with a variety of preparations containing biodynamic compost, it accelerates the pace of germination, makes the seedlings vigorous and also prevent the occurrence of fungal diseases. In addition, biodynamic gardeners support using rainwater for watering the seeds as well as seedlings, as rainwater contains dashes of nitrogen, which is collected when the water from the cloud falls all the way through the atmosphere. According to biodynamic experts, the seedlings are able to absorb the nitrogen easily. However, using rainwater may not be a good thing to do in polluted areas or nearby places where the wind is flowing from the polluted areas.

It may also be noted that the moon affects the sowing pattern by biodynamic gardeners. Substantiating their process, they reveal that the level of underground moisture rises to the surface of the soil during the lunar fortnight when the moon is visible at night (also called ‘waxing of the moon’). The gravitational pull exerted by the moon brings up the maximum amount of subterranean moisture in the soil during the full moon phase. Hence, seeds that are very slow in germinating are generally sown during a full moon and a week following it. On the other hand, seeds that sprout very rapidly, in addition to the seeds that germinate very slowly, are sown two days prior to the new moon and during the following seven days.

When the seeds have sprouted and produced numerous leaves, the seedlings are all set to be transplanted into small, separate containers. In case you want to transplant the seedlings into beds outdoors, make sure that you plant the seedlings no less than 1.25 inches apart. Also be careful while handling the small plants, ensuring that you do not cause any harm to their tender stems as well as roots. You may prepare an excellent potting soil by blending compost, loamy topsoil and sharp sand in equal proportions. Allow the seedling to nurture in the pots for many more weeks with a view to enabling the tender plants to expand their root system as well as produce more new leaves. Once the plants have established their roots and produced numerous leaves, they are all set to be transplanted into their permanent positions outdoors.

Division

Often, perennial plants are propagated by dividing their crown – a procedure involving dividing a large cluster of plants into smaller clumps and replanting them. Generally, the crown division is undertaken during the fall when the plants are in a dormant state. However, some types of plants are also dividing in the early part of spring, prior to the beginning of the new season’s growth. In order to undertake crown division, you need to unearth the clumps carefully and cleanse the soil sticking to the roots using a brush with a view to seeing what you will be doing. Subsequently, separate the plants by pulling them apart or cut the clumps all the way through the top growth using a sharp knife or spade with a view to dividing them into many smaller clusters. Some of the plants that can be propagated well by dividing their clumps with a knife include mugwort, oregano, hyssop, and tarragon. On the other hand, it is better to separate the clumps of garlic, onion, mints and German chamomileusing a spading fork after you have evacuated them from the soil.

It is advisable that you should be very cautious while dividing the plants, because even the slightest damage to their roots may render them unviable for propagation. Be careful while separating the roots and ensure that every plant has its stem/ shoot and roots intact. Once you replant them, you need to water them carefully. In case you are undertaking the crown division during the fall, you also need to provide mulch to the clumps that have been replanted with a view to shield the roots during the harsh winter months.

While handling plants that are very tender or having elongated taproots, you should opt for their propagation by root division. When you undertake propagation by means of root division, you actually chop the plants’ roots into several pieces, each of them having a bud. As new shoots will develop from the buds, you should ensure that each root division has at least one bud attached to it. In addition, root division may also entail separating/ dividing the offshoots developed from subterranean corms, bulbs or tubers, provided these offshoots have the potential to grow into new plants.

Cuttings

Cuttings are of many dissimilar types, including leaf and bud cuttings; stem, root and leaf cuttings; softwood cuttings as well as hardwood cuttings. To ensure that the cuttings thrive and grow into new plants, you need to take them from vigorous plants and at the appropriate time; be cautious while setting the cuttings into a good quality rooting medium; and ensure that you keep the cuttings moist as well as warm till they give out roots.

However, hardwood cuttings are exceptional. Generally, these cuttings are made from the latest growth of deciduous trees and only when the trees have shed all their leaves. Actually, hardwood cuttings are an excellent way to produce sufficient plants to serve as windbreaks and hedges. Each hardwood cutting ought to be roughly between 6 inches and 8 inches having at least three to four nodules or nodes. The node at the uppermost of the cutting should be just roughly one inch from the top. Tie up the hardwood cuttings and put the bundle in somewhat damp sand and keep them in a refrigerator at roughly 50°F for about a month. Subsequently, keep the cutting in further cold temperature, just higher than the freezing temperature, till the spring thaw. When the last spring frost is over, plant these cuttings in a furrow with just their topmost node (bud) remaining above the soil. Water these cuttings every day and keep a careful eye on them till they begin to develop new shoots. Here is a word of caution: ensure that you do not store the cuttings in the refrigerator for an extended period or else they may possibly sprout even before you plant them outdoors.

Softwood cutting are also referred to as greenwood cuttings, which are made by cutting majority of the plants, counting those whose wood is tough. Usually, the new growths of healthy deciduous plants are used for greenwood cuttings. In fact, the stem that would be used as the cutting should split with crack when it is bent. However, if you are able to crush the stem between your fingers, it is considered to tender to be used for cuttings. On the other hand, if the stem just bends somewhat between your fingers, it is considered to be too mature for softwood cuttings. In fact, this is best way to test as well as know whether the plant is sufficiently mature to tolerate cutting, but yet quite young to produce an excellent cutting. Ideally, softwood cuttings should be done either in the latter part of spring or the early part of summer. However, the timings for making softwood cutting differ depending on the type of plant.

Usually, the length of the cutting differs from two inches to six inches. Ideally, you need to cut the stem at about 45° angle and roughly half an inch away from the bud (node) to separate the cutting from the original stem. Softwood cuttings are usually made from the branch terminals and, hence, often they are also referred to as terminal cuttings. Immediately after making the cutting, cover its base with a moist cloth or paper towel and put it in a plastic bag. Examine the shape of the cutting and carefully get rid of nearly all the leaves. It may be noted that having lots of leaves will diminish the prospects of the cutting taking roots.

Remove the cloth or the damp paper towel just before planting the cutting into a bed prepared with moist sand and tiny gravels. Make sure that the cutting stands straight and is properly supported by the medium in which it will take roots. If cuttings have been made in the latter part of the spring or early part of summer they should develop enough and healthy roots by autumn. However, if the cuttings have been made from plants resilient to winter, you may plant them outdoors with a view to allow them to become firm and also let them experience their first winter outdoors after you have relocated them into a medium prepared by mixing equal proportions of topsoil and sharp sand and fertilized by adding little quantities of compost. However, if you are growing the rooted cuttings in containers or pots, you need to keep them under careful observation all through the cold spells, because the soil in the pots freezes much more rapidly compared to the soil in the gardens.

Layering

The traditional method of producing a new plant from a plant that already exists is known as layering. This process is employed very frequently for propagating shrubs whose roots are very difficult to cut or separate. Different from cuttings, wherein a part of the plant (especially the stem with nodes) is cut from the mother plant, layering involves encouraging a branch to give out roots by bending it down into the soil and keeping it in that position for a period of time by means of putting a weight (usually a rock) on it. In fact, the process involved in propagation through layering is a very secure one, as it can be undertaken without causing any damage either to the parent or new plant. However, the downside of layering is that it takes much more time to propagate a plant by this method compared to root division and cuttings.

Ideally, layering should be taken up during spring prior to the bud of the plant you have selected open up. First, you need to select a good and sturdy branch, which is long as well as sufficiently flexible so that it can be curved to the ground without much difficulty. Next, you bend the branch to the ground and make a marking at the place where you want it to develop new roots. Remove a small portion of the bark from the place which will be buried into the ground for rooting. Ensure that while cutting the bark you do not cause any damage to the plant tissue just under the layer of the bark. Put in some sand, sphagnum and peat moss to the soil at the portion of the branch where you have removed the bark and set the layered part of the branch into the ground for rooting using a forked stick or a small rock. You may also use a hairpin to hold a slender branch in its place into the ground. Make sure that the top part of the branch that you have layered sticks out from the ground – the tip should never be buried under the soil. At times, gardeners keep the tip of the layered branch out of the soil by fastening it with a stick or by bracing the branch.

By the next spring, it will be time to unearth the layered branch. In order to grow the new plant, unearth it cautiously with a view to protect the new roots and then cut the original branch at a place a little lower than where the new roots have developed. Subsequently, plant this rooted branch in the same manner as you would plant a cutting. This method of propagating plants is known as simple layering. Tip layering is another way you can propagate plants and it is actually a more rapid method of proliferating plants. This method involves only burying the tip of a plant, not the stem, during spring. When you undertake tip layering you can unearth and start growing the new plant in the next fall.