Gadenin日本語Get the appSeed is the practical route
Eucalyptus germinates well and grows fast, which makes seed by far the most reliable way to get new plants. The seed itself is very fine, often mixed with chaff of similar appearance, so a packet that looks like it contains hundreds of seeds may contain a few dozen viable ones surrounded by debris. Sow more thickly than you would for a vegetable and expect uneven germination.
Freshness matters. Seed stored warm and damp loses viability quickly, whereas seed kept dry and cool holds for a couple of years. If germination is poor from a batch you know was sown correctly, suspect the seed rather than your technique.
Sow in late winter or early spring under cover so the seedlings have a full growing season ahead of them, or at any point in the warm months if you can protect the young plants through their first cold spell. Seedlings raised in autumn spend the cold months as vulnerable little plants with nothing to gain.
Sowing method
The whole exercise turns on drainage and on not burying the seed. Eucalyptus seedlings are killed by damping off faster than almost anything else at that size, so a gritty open potting mix and air movement matter more than warmth does.
- Mix an open potting mix Two parts seed-starting mix to one part perlite, coarse sand or fine grit. Fill pots or trays, level without compressing hard, and water thoroughly from below before sowing so you are not disturbing seed with a watering can afterwards.
- Sow on the surface Scatter seed and chaff thinly across the surface. Cover with no more than a light dusting of fine grit or vermiculite, just enough to hold the seed in contact with the compost. Seed buried a quarter inch (5 mm) deep will mostly not come up.
- Give warmth and light Hold the compost at 65-75F (18-24C) in bright light. Germination usually starts in one to three weeks. A propagator lid helps hold humidity, but vent it daily; still saturated air is what causes seedling collapse.
- Water from below, sparingly Stand pots in shallow water until the surface darkens, then lift them out. Never leave them standing. Let the surface dry slightly between waterings once the seedlings are up.
- Transplant early Move seedlings into individual deep pots as soon as they have their first pair of true leaves. Eucalyptus makes a strong downward root immediately, and a seedling left in a tray for an extra fortnight is already checked. Deep pots beat wide ones.
- Harden off and plant out small Grow on in bright, airy, cool conditions rather than pushing with heat. Move outside gradually over two weeks once frost has passed, and plant into the ground the same season while the plant is still small. The longer it sits in a pot, the worse it will anchor.
Do not pot up into large containers hoping for a bigger plant faster. Eucalyptus roots to the bottom of a pot within weeks and then circles; each unnecessary potting stage adds a spiral to the root system that never straightens out after planting.
Cuttings: honest expectations
Eucalyptus has a genuine reputation for being difficult to root from cuttings, and the reputation is deserved. Commercial propagation of selected clones is done with very young stock plants, precise misting, bottom heat and hormone treatment, and even then the strike rate is modest. Wood taken from a mature garden plant almost never roots at home.
If you want to try anyway, the only material worth using is soft juvenile regrowth from a freshly coppiced stool, taken while it is still flexible and before it firms. Wood from adult-foliaged branches is not worth the bench space.
Treat any success as a bonus rather than a plan. If you need five plants, sow seed and try cuttings on the side; do not rely on cuttings to fill a hedge.
| Method | Best material | Conditions | Realistic outcome |
|---|---|---|---|
| Seed | Fresh, dry-stored seed with chaff | Surface sown, 65-75F (18-24C), open potting mix | Reliable; the method to use |
| Softwood cuttings | Juvenile regrowth from a coppiced stool | Mist or sealed case, bottom heat 70F (21C) | Low strike rate, worth trying only for fun |
| Semi-ripe cuttings | Firming shoots from a young plant | Sealed case, bottom heat, rooting hormone | Rarely succeeds outside a nursery |
| Hardwood cuttings | Mature stems | Any | Effectively never roots |
| Layering | Low flexible juvenile stem | Pegged into free-draining soil for a season | Occasionally works on a coppiced plant |
| Division | Not applicable | Not applicable | Eucalyptus does not divide; it is a woody single-stemmed plant |
Self-sown seedlings
A mature eucalyptus in a warm climate sets seed and drops it, and you will find seedlings coming up in gravel, in path cracks and under the canopy. These transplant well while they are under about six inches (15 cm) tall and are effectively free plants, so lift them early if you want them.
The same fact is a nuisance if you do not. Seedlings grow very fast and a missed one against a wall becomes a real problem within two seasons. Pull them while they are small; once the taproot is established, hand-pulling snaps the top off and the stump resprouts.
What to record from a batch
Note the sowing date, the compost mix, the temperature you held and how many days passed before the first seedling appeared. Germination timing varies enough between batches that a single written record from a successful sowing is worth more than any general figure.
Also record how many seedlings survived transplanting seedlings and how tall they were when planted into the ground. That number is what tells you how many to sow next time, and it separates a seed problem from a technique problem when a later batch disappoints.