Azaleas may seem like a shrub that would be challenging for the home gardener to propagate. The truth is both evergreen and deciduous types of Azaleas can be easily and relatively quickly grown from stem cuttings, layering, or seed. The only difficult part of propagating Azaleas will be waiting for them to be mature enough to flower.
Photo by Jerry Norbury, unmodified, Flickr, Copyright CC BY-ND 2.0
Methods To Propagate Azaleas
Choosing a method to propagate your Azalea shrub depends on if it is a deciduous or evergreen type. Evergreen Azaleas will readily multiply by softwood cuttings and seeds set later in the fall, whereas deciduous Azaleas are much easier to grow with stem layering techniques. Stem layering is where roots are encouraged to form on a branch still attached to the mother plant. The branch can be weighed down to the ground with a rock or stake, or rooted in the air by wrapping it in moist sphagnum moss covered in plastic. The technique results in sturdy plantlets that can be transplanted after one or two years.
Stem cuttings from evergreen Azaleas are the most successful when taken in the early summer after the shrub has finished blooming. Choose stems with new growth emerging and no flower buds. These cuttings will take faster and are able to put all of their energy into forming new roots.
Photo by Jerry Norbury, unmodified, Flickr, Copyright CC BY-ND 2.0
Azaleas are similarly easy to grow from seed because they do not require any complicated stratification techniques to germinate. Allow some of the flowers to remain on the shrub and develop seeds. Seeds from species varieties are more likely to grow true to the original plant. Hybrid Azaleas also develop seeds, although they often are not true to the parent plant and give unexpected outcomes. For adventurous gardeners, this may be appealing and an interesting challenge.
What You Need To Propagate Azaleas
For cuttings:
- Sharp, sterilized pruners or a utility knife
- Sterilized potting mix and perlite mixed 1:1 or perlite only
- 4-6 inch diameter pots
- Plastic bag or other clear covering to trap humidity until the cutting has rooted
- 6-8 inch long stems cut from the tips of non-flowering (or recently flowered) branches
- Rooting hormone (optional)
For seeds:
- Fully ripened and dry seeds from your Azalea
- Grow lights for germination
- Heat mat or warm location that will consistently remain 65-75 degrees Fahrenheit
- Sterile, peat-free seed starting mix
- 2-4 inch pots for starting seeds
- Fine mist spray bottle or bottle top waterer to keep the potting soil moist
For layering:
- Sharp garden knife or utility knife
- Ground layering: a heavy rock or sod pins
- Air layering: aluminum foil or plastic wrap and grafting tape or another strong waterproof tape
- Peat-free potting mix
Best Time To Propagate Azaleas
Azaleas are best propagated by layering and stem cuttings in mid-summer and by seed in early winter.
For cuttings: Take softwood cuttings as soon as the shrubs are finished blooming in the late spring or early summer. Always select the healthiest shoots on a shrub, and use sterilized pruners or knives so as not to transmit diseases to the mother plant. Place the cuttings in a semi-sheltered location such as an unheated greenhouse or next to a building where they can receive natural precipitation and be monitored easily throughout the winter.
For seeds: Allow some of the flowers to remain after they have died back so that your shrub will form seed. Harvest seed pods when they have turned brown and are dry to the touch, which will be anywhere from the end of summer into the fall. Keep the seeds in a dark, cool, and dry location until ready to plant in the late winter. Paper envelopes, Ziploc baggies, or any small jar with a lid works fine. Azalea seeds do not need a period of chilling or other stratification methods to successfully germinate. Start the seeds indoors near a source of heat that remains 65-75 degrees F night and day. Sow the seeds on the surface of the potting mix and keep them slightly damp until germination. Set the trays on a heating mat or on top of a refrigerator where the air stays warm. The Azalea seeds also require light to germinate.
For layering: Layering can be done at any point in the growing season. The layered portion of the branch will need to be left alone for at least one year to allow a good root system to form before detaching the plantlet from the mother shrub.
Steps To Propagate Azaleas
Starting softwood stem cuttings is one of the best propagating techniques to learn and can be used with a wide variety of plants. These are the steps for taking a successful Azalea cutting.
Step 1 - Cut portions of stem that are 8-10 inches long and either have no flower bud or the flower has died back. Make the cuts just above a set of leaves or buds to keep the remaining shrub neat with no bare stems.
Step 2 - Carefully remove all but the top cluster of leaves, exposing the growth nodes on the stem. Cut the stem again so that it is no longer than 6 inches.
Step 3 - Fill a pot with a mix of all-purpose potting mix and perlite (with a ratio of 1:1) or straight perlite, to within a half inch of the rim. Gently firm down the material to give the cuttings a solid base for support.
Step 4 - Dip the cut end of the stem in a dry rooting hormone (optional) and gently tap off the excess. Rooting hormones are not necessary, although they may help woodier stems grow roots faster.
Step 5 - Push the cut end of the stem into the pot. Keep the cuttings to the far edges of the pot. This allows for good air circulation and gives the roots plenty of space to grow. Typically 3-5 cuttings fit into a 4-inch pot.
Step 6 - Water the pot with a gentle shower from a watering can or a bottle-top watering sprinkler.
Step 7 - Place a plastic bag over the top of the pot and secure it loosely with a rubber band or twine. This creates a mini greenhouse to help keep the cutting moist until roots begin to form.
Step 8 - Place the cuttings in a warm and bright spotout of direct sunlight, making sure that the rooting medium does not dry out.
Caring For Young Azalea Cuttings
After 2-3 months, the cuttings will begin to develop roots to support new top growth. When 2-3 new leaves appear from the top of the cutting, the new plantlet is ready to be repotted or planted into a nursery bed to grow on. Pot the new plants into individual pots at the same level they were growing as cuttings. Pots around 6 inches are a good size to grow Azaleas until they are transplanted into the landscape.
Gradually move newly planted Azaleas from a partially shaded location to more sun over the next 2-3 weeks. This hardening off will help the plants acclimate to their new growing conditions. Azaleas benefit from fertilizing with diluted liquid seaweed or fish emulsion when growing in containers. Apply the feed at half the recommended label strength on a monthly basis. Azalea shrubs are ready to plant out when the root system has filled the pot and roots begin to show from the drainage holes.
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Author Robbin Small - Published 8-02-2023 |