The flat is rotated once or twice a week to compensate for variations in light and temperature. Rooting usually takes about 6 weeks for evergreen azaleas and 3 to 4 months for large-leaf rhododendrons. Fertilize once a month with an acid-based azalea plant food like Peters.
Removing terminal buds promotes sturdy well-branched plants. Take cuttings of deciduous azaleas when the new growth is soft and pliant. This is often coincident with time of bloom in early June.
The ability to root decreases rapidly as new growth matures. Trim cuttings below a node overall length of cuttings 3 to 5 inches and dip in a rooting hormone containing fungicide. In late August, transplant cuttings that are rooted and grown on in the greenhouse with supplementary light hours a day to prevent dormancy and induce new growth.
As new growth develops in the spring, transfer plants to a shaded environment. Layering: This is the easiest form of propagation for the home gardener. A lower branch is held down on soil not mulch with a stone.
A slit is cut in an area in contact with the soil and the cut is treated with a rooting hormone. Then the cut area will sprout roots.
When the roots are developed enough to support the end of the branch, usually in 2 years, the rooted-branch is cut from the parent plant and transplanted.
Grafting: Grafting was the standard propagation technique prior to the s, and is still popular in Europe where acidic soil is not common and plants that are hard to grow can be grafted onto rootstocks of plants that are easy to grow like R.
The big advantage of grafting is the use of disease resistant, soil tolerant rootstocks. Also, some hybrids don't produce good root systems, so if the plants are grafted onto a good rootstock, this is no longer a problem.
There are two basic techniques of grafting, one involves grafting onto rooted rootstocks and the second involves grafting and rooting the rootstock at the same time. Then the scion is grafted to the rootstock and secured with an elastic band. See the referenced articles below for detailed instructions. The cuttings for the rootstock and the scion are taken at the same time. The scion is side grafted to the rootstock cutting and secured with raw cotton string which rots naturally.
The top is left on both cuttings. The rootstock is rooted immediately after the graft is secured. While a stronger rooting hormone will increase their chances of rooting, it makes it harder to get them to break dormancy and go into active growth. The cuttings will do best in a greenhouse with bottom heat from electric heat cables at around 75 degrees F, and with a mist system during the day to ensure they get all the moisture they can use.
However, they can also be rooted under plastic as described for evergreen azaleas. As soon as they have rooted, the cuttings should be fertilized with half strength liquid fertilizer and given three to four hours of extra light through the summer to force them into active growth.
Use 75 watt incandescent bulbs or a mix of incandescent and fluorescent bulbs, as close as possible to the cuttings without burning them, which is about 6 inches away.
In late September, stop the extra light to let the cuttings harden off for the winter. Do not disturb their roots until they begin to grow the following spring, at which time they may be potted up or moved to a bed in the garden. Cuttings from azaleas which are difficult to root can be grafted onto an azalea with a good root system.
The scion or cutting wood should be dormant, and the root stock in active growth. They should both be decidous or both evergreen. Using a greenhouse is best, to force the root stock into active growth in later winter or early spring, while the plant to be reproduced is still dormant. Follow any standard grafting procedure, being careful to match at least part of the cambium layers.
It is helpful to then wrap the union in damp sphagnum moss and cover the entire plant, scion and all, in a plastic bag. In about a month, after the scion begins to grow, gradually admit air into the bag until the scion hardens, after which the bag can be removed.
Azaleas grow readily from seed. The seed pods are plainly visible soon after the flowers drop, and become larger over the summer, eventually turning dark brown, splitting open, and dropping the seed on the ground. Only very rarely will the conditions be right for the seed to germinate and grow in the garden.
Instead, collect the seed pods before they open, and grow the seed under controlled conditions. Collect the seed pods as they begin to turn brown, usually around the time of the first frost in the fall. Put the pods of one variety into one container, such as an envelope or a small paper muffin cup, and mark it with the variety.
After a few weeks, the pods will split and begin to spill out their seed, as many as seeds per pod. Clean the seed by separating it from the pod and other debris. Prepare some flats, which may be any size and material, by putting a mixture of sand and peat or leaf mold or perlite to within about an inch of the top, and covering it with a half inch or so of milled peat moss. Soak it until it is thoroughly wet, and let it drain out the excess water. It may be convenient to soak it separately in a tub of water, and fill the flat with handfuls of the mixture squeezed free of excess water.
The plastic containers used by supermarkets for pastry and salads, about three inches high and various widths and lengths, are ideal for small quantities of seedlings. Sow the seed in the winter, indoors, to give the seedlings as much time as possible before being subjected to outdoor winter temperatures.
Broadcast it over the flat and mist it lightly to settle the seeds. Cover the flat tightly with plastic, and put it under artificial lights or on a north window sill. The seed will germinate in two to six weeks, depending on the variety. When the seedlings have developed two sets of leaves, carefully transplant them into other flats filled with a similar mixture of sand and peat or leaf mold or perlite.
Use a toothpick or similar fine instrument to remove a seedling, and to plant it into the new flat. Use a two or three inch spacing, as they will probably stay in this flat for a year or more. When the flat is filled, water the seedlings with a fine spray to settle the soil around the roots.
Cover it with plastic, and place it under lights or on a north facing window sill, or outdoors in the shade if the weather is reliably above freezing.
After a few days, the seedlings should be established and the plastic can be removed. Fertilize with very weak solutions of liquid fertilizer to maintain active growth.
After they have grown a year, the seedlings are ready to be potted up or planted out. The soil should be almost a solid mass of fine roots, and the soil can be cut into squares rather than trying to find out which roots go with with plant. They are quite tender, and should be given ample water and ample shade. Susan Lundman began writing about her love of gardening and landscape design after working for 20 years at a nonprofit agency.
She has written about plants, garden design and gardening tips online professionally for ten years on numerous websites. By Susan Lundman Updated November 28, Related Articles. Methods for taking cuttings are the same for both deciduous and evergreen azaleas:. Choose a 2- to 5-inch stem tip that's part of the season's new growth, that's still somewhat green and that bends instead of snaps. Cut the stem for propagation in the morning when the plant is most hydrated.
Make sure that your plant was well-watered the previous day. Make your cut just below a bulging node that would have formed a new stem if you had left it on the plant. Carefully remove all lower leaves from the bottom third of the stem, being careful not to nick the stem itself, leaving about three leaves at the top of the stem. Plant the cutting about one-third of its depth into the soil. Water the cutting, taking care not to wet the leaves.
0コメント