Gadenin日本語Get the appTake the wood at the right stage
The reliable material is a semi-ripe cutting: this season's growth that has firmed at the base but is still flexible and green towards the tip. Bend a shoot gently. If it flops without resistance it is too soft and will rot before it roots; if it snaps cleanly it is too old and will sit there for months. The right wood bends into a curve and springs back.
That stage arrives from midsummer into early autumn on outdoor plants, and can be found almost any time on an indoor plant that keeps growing. Take material from a healthy plant in the morning, when the shoots are fully turgid, and keep it in a sealed bag out of the sun until you can deal with it. Cuttings that wilt before you insert them rarely recover.
Choose non-flowering shoots. A shoot carrying buds is putting its resources into flowers rather than roots, and the buds will drop anyway once the cutting loses its root supply. If the only material available has buds, pinch them off before you insert.
Softwood cuttings taken in spring also root, faster but with a much higher loss rate, since soft tissue collapses at the first hint of a fungal problem. Semi-ripe is slower and far more forgiving, which is what you want if you are only taking a handful.
- Cut a shoot four to six inches (10 to 15 cm) long Take it from the current season's growth, avoiding anything in flower or bud. Cut with clean pruners or a sharp blade and drop it straight into a bag to hold the moisture.
- Trim below a leaf joint Recut the base cleanly just below a node, where the concentration of growth tissue is highest. A ragged crushed base rots instead of rooting.
- Strip the lower leaves Remove the leaves from the bottom half so that no foliage will sit in or on the compost. Keep two to four leaves at the top, and halve any very large ones to cut water loss.
- Dip in rooting hormone Optional but it noticeably improves the strike rate and the evenness of rooting on semi-ripe wood. Tap off the excess rather than leaving a thick coating on the cut.
- Insert into a free-draining acid mix Equal parts acidic potting mix and perlite or sharp sand, firmed lightly. Insert the lower third, space the cuttings so leaves do not touch, and water once to settle the mix around them.
- Enclose and keep warm A propagator lid, or a clear bag held clear of the leaves by canes. Keep it in bright indirect light at 70 to 75F (21 to 24C). Bottom heat from a heated mat makes a large difference to both speed and success.
The weeks after insertion are where cuttings are lost
Gardenia cuttings usually root in four to eight weeks in warm humid conditions, and a good batch strikes at a high rate. Almost all the failures come from two causes that pull in opposite directions: the cutting dries out because the case was opened too much, or it rots because the case was never opened at all and the compost stayed sodden in still stale air.
Ventilate briefly every few days. Lift the lid or open the bag for a few minutes, wipe away condensation, and remove any leaf that has gone yellow or brown before it turns into a mold source. One rotting leaf in a closed case can take out the cuttings either side of it within a week.
Keep the compost damp but never wet. Once the cuttings are inserted and settled, the enclosed environment recycles most of the moisture and you will need to water far less often than instinct suggests. Judge by weight of the tray or by feel, not by a schedule.
Resist the urge to tug at them. Gentle resistance when you very lightly hold the top of a cutting means roots have formed; repeated pulling breaks the fine new roots off. Better signs are new leaf growth at the tip and roots appearing at the drainage holes.
| What you see | What it means | What to do |
|---|---|---|
| Leaves still firm and green after three weeks | Normal, roots have not formed yet | Leave alone, keep warm and humid |
| Base blackening, cutting soft and limp | Rot from wet compost or stale air | Remove immediately, ventilate more often |
| Leaves dropping while the stem stays green | Humidity too low, or direct sun on the case | Reseal, move out of direct sun |
| White mold on the compost surface | Poor air movement, too wet | Ventilate daily, scrape off, water less |
| New shoot growth at the tip | Rooted and actively growing | Start hardening off over two weeks |
| Roots visible at the drainage holes | Fully rooted | Pot up individually into acidic potting mix |
Weaning and potting up
The transition from a closed case into ordinary room air kills more gardenia cuttings than the rooting itself, because a rooted cutting has leaves adapted to near-saturated humidity and a root system far too small to replace what those leaves lose in dry air. Do it gradually over about two weeks: open the vents a little, then more, then leave the lid propped, then take it off entirely.
Pot each rooted cutting individually into a small pot of acidic potting mix, using a pot only slightly larger than the roots. Too big a pot holds wet compost the young roots cannot use, and the young plant sits and sulks. Water with rainwater from the start, so the compost never drifts away from acid.
Pinch out the growing tip once the young plant has made a few inches of new growth. A gardenia left unpinched makes one leggy stem; pinched, it branches from the base and becomes a full, bushy plant, which is the whole difference between a good specimen and a disappointing one in three years.
Do not feed until roots have filled the small pot and the plant is clearly growing, then use a very dilute ericaceous feed. Expect flowers in the second or third year. A young plant that produces a bud in its first year is better pinched than allowed to flower, so the energy goes into structure.
Label every batch with the date it was taken and the parent plant, and note the date it rooted. After two seasons you will know exactly which week of the year gives you the best strike in your own conditions, and that beats any general advice about timing.
Layering, and what seed gives you
Layering is slower than cuttings and almost impossible to fail, because the shoot stays attached to the parent and keeps receiving water and food the entire time it is forming roots. It suits anyone who only wants one or two new plants and does not want to manage a propagator.
Choose a low flexible branch that can be bent down to soil level. About a foot (30 cm) from its tip, wound the underside of the stem with a shallow slanting cut, dust the wound with rooting hormone, and peg the stem down into a shallow depression of acidic potting mix. Cover with two or three inches (5 to 8 cm) of the same mix, weight it with a stone, and stake the tip upright.
Keep the layered point damp through the growing season and leave it alone. Rooting typically takes a full season, sometimes longer. Check by gently scraping back the covering the following year, and only sever the layer from the parent once there is a genuine root system, then leave it in place for several more weeks before lifting.
Seed is a different proposition. Seedlings are slow, variable and take several years to flower, and they will not reproduce the parent plant. That variation is exactly the reason to do it if you are curious about raising something of your own, but for reproducing a plant you already like, cuttings and layering are the only sensible routes.