Evergreen azaleas can be propagated at home quite easily by making cuttings or by layering. While not quite as easy to do asgeranium, the average amateur will have no trouble.
Although he may not get a 100 per cent take, he will get enough takes to increase his supply, if he starts with enough slips. The first step is to prepare the rooting medium and the box that is to hold it.
I prefer half-flats. These are regular flats which I cut in half, moving the one end piece up to the middle and nailing it in place.
I try to find a wooden box a little larger and twice as deep so I can put my half-flat inside and cover the deeper box with plastic without it touching the plants in the lower one. It is a good idea to sterilize the half-flat.
I do this by soaking it overnight in a lysol solution, then allowing it to dry in the sun before it is used. Some of my friends pour boiling water over the flats and let them sundry.
The rooting mixture should be about 60 per cent washed river sand and 40 percent vermiculite or peat moss. Pack the rooting mixture into the flat firmly, leaving one-half inch of space at the top. Moisten the mixture thoroughly.
We set our half-flat in the sink to soak up, then allow it to drain overnight. Commercial growers usually use pure sand to root their cuttings, but they either have automatic misting or are nearby all day so they can sprinkle them freely.
The tune to take the cuttings depends upon the condition of the wood. I have had my best success with cuttings taken in June.
Frederic P. Lee, author of “The Azalea Book,” says “a cutting must not be soft enough to bend like rubber nor brittle enough to snap like a match stick.”
I have never tested my cuttings for these traits. I shear my azaleas to shape them after they bloom and use the biggest and best-looking pieces for cuttings.
Remove Lower Leaves
Clip the leaves off the lower half of the cuttings and wrap them in a wet newspaper to keep them crisp and fresh. I mark the medium in two inch squares with a thin metal ruler, pushing it down into the medium almost to the bottom of the flat
I want to set the cuttings two inches apart and two inches from the sides of the flat.
Taking one cutting at a time from under the wet paper, I dip the stem into a rooting hormone about an inch, push a sharpened chop stick into the corner of a square to enlarge the hole, and slip the cutting into the hole almost up to the foliage.
Then, using the chop stick, we push the rooting medium singly against the stem. Getting the rooting hormone deep enough is important, because azaleas root along the stem, not at the base of the cutting.
Also, leaves should not touch the rooting medium. Water the plants in, using a small sprinkling, can without a rose so only the rooting medium is wetted.
Set the flat in the deeper box and cover with plastic, tucking the edges of the plastic under the sides and end of the bigger box. Place the box in a shady place where it won’t be disturbed. It will take from six to eight weeks for the cuttings to root.
Usually the rooting medium stays moist, but it is wise to check it at least once a week. If it dry out, the cuttings will die. Always water only the rooting medium.
At the end of eight weeks, check to see if roots are formed and if so remove the plastic covering but leave the flat in the shade. After about a week move the rooted cuttings into pots using a mixture of equal parts leaf mold, sand and peat moss.
Wait a week then fertilize the plants every two or three weeks with a weak (quarter strength) solution of liquid fertilizer. Move up to larger pots as needed or transplant to the garden using the same mixture of leaf mold, sand and peat.
Remember, azaleas like good drainage but they also like plenty of moisture.
Often gift plants of azaleas die, due to the potting medium becoming dry. Commercial growers usually use pure peat as a growing medium and once this material gets really dry it is most difficult to wet.
I suggest that a few slips be made shortly after the gift plant arrives so if something happened you wouldn’t be left with just a dead plant. It is often surprising, but slips from these gift plants often grow and flower much better than the gift plant.
Because conditions in the home garden vary so much from those in the commercial grower’s glasshouses, I recommend gift plants be repotted or set out in the garden as soon as possible.
Until the replanting takes place the pot portion should be held under water (in a pail not under a faucet) until all bubbles cease. This should be done about twice a week.
This does not take the place of regular watering except on the day that it is done. When placing a gift azalea in the garden, soak the root ball, and then work some of the growing medium off the roots so they can be spread out to give good contact with the new growing medium.
I recommend soaking the root ball then cutting through the root ball toward the base of the plant and spreading the roots out when transplanting azaleas.
Layering is still the surest way to get a new plant or two from a given azalea. This entails pegging a branch securely against the soil and keeping the area moist until roots form when the branch can be clipped off and potted.
If the branches are too short or too stiff, a pot of the right height can be filled with a suitable rooting medium and placed close to the branch to be used.
The method consists of making a cut on the lower side of the branch and about half way through it. This is don wont the diagonal with a knife, not pruning shears. The cut should be about one inch long.
Bury the cut section about three inches deep in the prepared medium, tie the tip to a stake to hold it upright and place a rock on the buried portion to hold it firmly. The best time to use this method is early spring or early fall.