Many species of lavender are perennial plants, meaning they can live for two years or more. These types of plants continue to grow as the seasons pass and can eventually outgrow your garden. However, lavender is a particularly fragile plant when divided, so experienced gardeners almost always prefer to use cutting rather than create new plants. Unfortunately, if your plant is too big, if it is in danger of dying or has poorer flowering from year to year, it may be worth resorting to the division process.
Steps
Method 1 of 4: Deciding How to Reproduce Lavender
Step 1. Use the cutting instead of dividing the plant to create new seedlings
If your goal is to create new plants, choose the cutting instead of dividing the plant. The division has a high mortality rate of the plant and should only be used if necessary for the survival of the plant itself, using the criteria described below.
- Go to the "Grass Cuttings" method for a faster type of cutting that needs to be done in the spring or summer.
- Go to the "Offshoot" method if you have enough space and time to allow the roots of the branch to develop before removing it from the plant. This process can be done at any time, but it takes at least three months of growth before the branch can be separated.
Step 2. If your lavender has overgrown, try pruning it
Due to the high probability of plant death following division, not even an overgrown lavender plant should be divided. Instead, do a hard pruning, cutting 1/3 of the plant once every three years. Prune in the spring and control lavender growth by removing the youngest stems, not the oldest and toughest ones in the center of the plant.
If the older, more resistant stems are already out of size for your garden, consider making several cuttings and removing the old plant entirely by the time the new ones have taken root for a year. Splitting is a quicker solution but less likely to succeed
Step 3. Before proceeding with dividing the plant, look for signs of noticeably reduced flowering from one year to the next
Note how many flowers your lavender plant produces and compare with the previous year. A slight or temporary decrease may be due to climatic differences. However, if the decrease has been steady and substantial for two years or more, the plant may need to be divided. A smart move could be to generate new plants by cuttings and observe the progress of the old plant.
Step 4. Examine the center of the lavender plant
Older plants may begin to die in the center and produce flowers only on the outside. This is one of the few situations where division becomes necessary. However, there is a high risk of death for any lavender plant following division.
Opinions differ regarding the mortality rate following the division of an old plant compared to a younger one
Method 2 of 4: Taking Cuttings from the Lavender Plant (Grass Cuttings and Woody Cuttings)
Step 1. Start in the spring or summer
Take the cuttings during the warm growing season, otherwise the roots will fail to form. Cuttings are more likely to root if they are cut early in the spring, but if you want to have more flowers, you may want to wait until summer, then take the cuttings after the plant has flowered. It is not recommended to wait beyond mid-summer, unless you live in an area where temperatures never drop below freezing (or only very late in the season): plants need at least six weeks to take root first. of frosts.
Step 2. Select a branch that has at least two leaf nodes
The nodes are those points on the branch from which the leaves emerge. Choose a young branch, placed low in the plant, with at least two nodes. There are two different ways to select a branch:
- The grassy cuttings they only concern the new stems of the year, just born, which have not yet turned brown and woody. These cuttings grow faster but are only effective if the stem is at least 12 cm long and if it includes at least two leaf nodes.
- The woody cuttings they concern brown and woody stems but must still have at least 2, 5-5 cm of soft and newly born part on the top. These cuttings require rooting hormones, available at garden stores, to encourage root system growth.
Step 3. Purchase rooting hormones (sometimes optional)
Rooting hormones are needed to grow woody cuttings, while they are optional for grassy cuttings, since young stems are able to take root on their own. Rooting hormones can be useful for grassy cuttings if the cuttings were removed late from the mother plant, which is less than six weeks before the expected frosts begin.
Check the label and ingredients of rooting hormones before purchasing. Choose a product that contains root hormone in addition to fertilizer and vitamin B1
Step 4. Prepare pots or trays of special soil
Prepare trays or pots to plant the cuttings in for the first few weeks after cutting them. Since rootless plants are sensitive to both drought and excessive humidity, use a special mix of 50% organic compound and 50% perlite to retain water at the proper level. Alternatively, you can use similar mixes that can be purchased in gardening stores, such as a mix of sphagnum and perlite.
Clay jars are preferable to plastic ones due to their "breathability", especially if you soak them overnight before moving on to the next step
Step 5. Cut the twig with a sharp, clean knife
Sharpen and clean your knife if necessary to prepare for a clean cut with little chance of spreading infection. Cut the sprig just below the leaf node to remove a cutting that is at least 13 cm long, which includes at least two leaf nodes. The longer the cutting and the more leaf nodes it includes, the greater the chance that reproduction will be effective.
It is not recommended to use scissors, as they may crush the stem and make it more difficult for roots to appear
Step 6. Cut off all leaves except the cluster at the top of the stem
Leave only the leaves on top of the stem, as they will provide energy for the new plant. Use the knife to cut away the other leaves of the plant, so that the plant can direct its energy towards the formation of the roots, rather than into the excessive foliage.
Be careful not to damage the bark as you remove the leaves
Step 7. Soak the base of the cutting in rooting hormones (sometimes optional)
Follow the instructions on the product label to dilute it properly, whether it is in concentrated or powdered form. Dip 2 cm of cutting, starting from the base, into the specially prepared hormone solution.
This step is required for woody cuttings, but is optional for grassy ones, as discussed above
Step 8. Plant the cuttings in the previously prepared pots and water them abundantly
Place the cuttings in the pots you have prepared, just enough for them to stand upright. Water abundantly, depending on the size of the pot.
Step 9. Keep the pots moist and in the shade, but gradually begin exposing the cuttings more to the sun and giving them less water
Too much water is a common mistake when it comes to lavender cuttings. After the first immersion in water, water them only when the soil is dry, not when it is still wet. Shade helps to lessen damage from transplant stress for the first few days, after which plants can be gradually moved to brighter environments.
Greenhouses can be too humid environments for lavender cuttings. However, if they appear limp or dry after a couple of days, moving them to a greenhouse or under a nylon tarp can help retain moisture until roots are developed
Step 10. Transplant the cuttings into a larger pot or soil as soon as roots form
After at least three weeks, usually after six weeks or more, strong roots will have formed in the pots or trays. When the roots are firmly attached to the potting soil you can move the whole thing into a larger pot or into the soil. Plant the cutting in rich, draining soil and care for it as you would any lavender plant.
Method 3 of 4: Offshoot Method
Step 1. Choose a young, small twig near the base of the plant
For each plant you want to reproduce, choose a sprig attached to the outer base of the lavender. A young, flexible branch is needed, or one that grows horizontally just above the soil surface.
There are several methods of offshoot. The one illustrated in this guide is simple and low-risk, but it can be tiring if you plan to reproduce a lot of plants. Refer to the "Tips" section if you plan to reproduce your lavender plant in dozens of different plants
Step 2. Bury the central part of the twig in a shallow hole
Dig a 10-15cm hole in the soil, a short distance from the mother plant. Dig it in a location where you can fold the middle part of the twig inside the hole, with the leaves and flowers remaining above the soil on the other side.
Step 3. Pin the twig into the hole
Make sure that the stick does not come out of the hole by holding it in place with stones or a stake. Bury the central part of the twig in the hole and leave the flowering part outside.
Step 4. Keep the buried sprig moist
Water the basement from time to time, keeping it moist but not too much. Be careful not to let the soil run dry during the hot summer months.
- It is not recommended to water the sprig as long as the plant is dormant during the winter.
- Mulch can help the soil retain water, but it can also overheat it excessively during the summer months.
Step 5. Dig up the sprig and cut it back after at least three months of the growing season
While you can start this process at any time, the twig will not develop a strong stem and good root system until the spring and summer growing season. After three to four months of growth, preferably when autumn begins, gently dig around the buried twig to see if any roots have formed. If there are and are holding the soil together, cut the branch so that the roots are on the same side as the flowering stretch.
Step 6. Transplant the cut branch as a new plant
Move the cut branch directly to its new location along with the surrounding soil to avoid damaging the roots. Keep the plant out of the wind until it develops stronger roots and care for it like any lavender plant.
Method 4 of 4: Divide a Lavender Plant
Step 1. Use this method only as a last resort
Unlike many perennials, lavender does not react well to division. Read the "Deciding How to Reproduce Lavender" section for more advice, or refer to their respective sections regarding cutting and offshoots if your goal is to produce new lavender plants.
Step 2. Divide in early spring
Lavender plants are dormant during the winter, although they retain their typical color. Wait until early spring before dividing the plant, but not until the growing season begins.
Step 3. Locate where to split
If the center of the plant is dead, you should be able to locate clusters of stems around the dead area attached to the same section of roots. Consider dividing the plant so that each new portion has at least three to five stems and roughly the same portion of roots.
It may be necessary to include more than one group of stems in the same portion of the plant
Step 4. Dig holes for the plants you have divided
Generally speaking, each hole should be twice as wide as the root cluster and about 30cm deep. Keep in mind that the root system will be smaller after splitting.
Step 5. Add enriched potting soil to the bottom of the hole
You can mix organic material, such as compost or pine bark, into your garden soil, or you can arrange a 7.5cm layer of this material at the bottom of each hole.
You can also add some fertilizer rich in phosphorus and potassium to the base of the hole
Step 6. Pull the lavender plant out of the ground, partially or totally
If the plant is not overly large, the center is not dead, or the divisions you made are not easily visible when the plant is in the soil, remove the plant completely before dividing it. Otherwise, remove some soil around the plant to see better and make the root system more accessible.
Pry the handle of the shovel to loosen the soil around the plant until you can remove it from the ground
Step 7. Use a shovel to divide the root cluster
Most lavender plants are not easy to divide, but if your variety has decent sized clusters of stems, you can try to divide it with a couple of pitchforks. You'll likely need to use a shovel to cut the plant, then use pitchforks to divide the roots.
Step 8. Bury each portion of the plant in its respective hole
Place the seedlings at the same depth as before, gently pressing the soil around as you fill the hole. Water them copiously after planting them to encourage root growth and rooting. Continue to care for the seedlings like a regular lavender.
Advice
- Taking a few cuttings from healthy lavender shouldn't cause any problems for the mother plant.
- You can sacrifice your lavender plant to make dozens of new cuttings, but only if the plant is between three and five years of age. During the spring, bury the last 30 cm of the stems under a mound of wet soil, shaking them and pressing the soil in order to remove any air bubbles. In mid-autumn, several weeks before the frosts begin, raise the mound and cut the stems where they have formed woody twigs.
