Independent comparisons. We may earn from shop links. More info

How to grow eucalyptus from seed in the UK

Updated: 21 October 2026

The packet in your hand may say the seed is easy and can be sown all year. That line is not a temperature, a depth, or a date. Hardy eucalyptus seed, in the RHS method, wants about two months of cold and a deep cell from around mid-February. Unwins Baby Blue wants about a week in the fridge and then 20°C, with almost no cover. This page is the method, not a ranking. Listings stay on the [eucalyptus seeds comparison](/hub/herb-seeds/eucalyptus-seeds). Peter F. used the RHS growing guide, the Unwins Baby Blue page, and amazon.co.uk notes from 19 October 2026. A purchase through our links can earn a commission at no extra cost to you.

The packet in your hand may say the seed is easy and can be sown all year. That line is not a temperature, a depth, or a date.

Our top picks

SAFLAX SAFLAX Tasmanian bluegum seeds

Best overall

SAFLAX SAFLAX Tasmanian bluegum seeds
5.3/10about £4.55
View offer
Unwins Unwins Eucalyptus Baby Blue

Alternative

Unwins Unwins Eucalyptus Baby Blue
2.8/10about £3.49
View offer
SaatPilot SaatPilot Eucalyptus parvula

Rank 3

SaatPilot SaatPilot Eucalyptus parvula
6.8/10about £4.99
View offer
On this page
  1. 1.Which chill to use
  2. 2.How to sow the seed
  3. 3.Light, water, and the first move
  4. 4.When a tray has failed

Which chill to use

Start from the packet, not from one number repeated online. For a hardy species the RHS says to chill the seed at 3–5°C for two months, then sow around mid-February so the plants can be outside by mid-summer. A labelled bag in a domestic fridge is enough. Unwins' page for Houseplant Eucalyptus Baby Blue is the short chill: about one week in the fridge, then 20°C, covered with vermiculite only because the seed germinates in the light, then grown on at a minimum of about 12°C. That recipe belongs to Baby Blue. It is not the instruction for Eucalyptus parvula, or for a blue gum packet that only says 'easy'. If nothing appears, Chiltern's note on E. parvifolia says to cold-stratify after a sowing has sat for about four to six weeks. 'Year round' is not specific.

How to sow the seed

Use a deep pot, a deep module, or a root trainer. Eucalyptus dislikes root disturbance, so one seedling per cell saves a prick-out. Fill with peat-free compost that drains. Surface-sow. The seed is fine, and a thick cap is how packets fail while the compost looks tidy. Chiltern says an E. parvifolia packet can contain chaff, and you sow the chaff with the seed. A light dust of vermiculite is the Baby Blue cover. SaatPilot's listing for E. parvula says a fine medium, even moisture, and light after the seedlings appear. Do not bury either kind of seed a centimetre deep. The SAFLAX kit at £5.25 includes coconut-fibre substrate with 100 seeds. That fibre is a sowing medium. It does not change E. globulus from an H3 tree into a hardier one. The seed-only packet at £4.55 needs any fine, peat-free mix you already trust.
SAFLAX SAFLAX Tasmanian bluegum seeds

Testsieger

SAFLAX SAFLAX Tasmanian bluegum seeds
5.3/10about £4.55
View offer

Light, water, and the first move

Bright light is the difference between a stocky seedling and a thread. A Spanish review on the SAFLAX seed-only blue gum said the stems were so thin they snapped. Give seedlings the brightest spot you have, and shade only the harsh sun Unwins mentions for new Baby Blue shoots. Water from below when you can. Cold plus wet compost rots seed and collapses seedlings. Take a cover off as soon as leaves show. Leave each seedling in its deep cell until the roots hold the compost. The RHS wants hardy plants outdoors by mid-summer, not as new potlings in November.

When a tray has failed

Do not invent a germination percentage. A UK review of Just Seed Silver Plate describes two seedlings from a 10-seed pack, and they stayed tiny. One UK review of SAFLAX blue gum says germination was fast. A Spanish review of the substrate kit counted about 15 seedlings from about 400 seeds. Those anecdotes say that 'easy' on a listing can still mean a sparse tray. If a hardy sowing shows nothing after about four to six weeks of warmth, Chiltern's rescue is a cold stratification and a fresh mix. Call an arborist only when a mature gum is rocking or pressed against a wall.

Common questions

Do eucalyptus seeds need the fridge?
Hardy species do, on the RHS method: about two months at 3–5°C before a mid-February sowing. Unwins Baby Blue is different: about one week in the fridge, then 20°C. A listing that only says 'year round' has not given you a chill time. Do not give rainbow gum the hardy two-month recipe just because both packets say eucalyptus.
How deep do I cover them?
Keep the cover thin. Baby Blue is sown so that light can reach it, with vermiculite rather than a cap of compost. Hardy seed is surface-sown or barely covered. A centimetre of compost is how fine seed disappears. If the packet contains chaff, sow the chaff as well instead of trying to separate every grain.
When do I sow in the UK?
For the hardy RHS recipe, sow around mid-February after the two-month chill, and aim to have plants outdoors by mid-summer. Baby Blue on the Unwins page is aimed at February to April, then kept at a minimum of about 12°C. A 'year round' line on an Amazon bullet is not a substitute for those dates.
Why are my seedlings long and thin?
Low light is the usual cause, especially on a dull windowsill while the compost stays wet. Move them brighter as soon as they emerge, without baking brand-new Baby Blue shoots in harsh sun. A Spanish review mentioned stems that snapped. Treat that as a warning about weak growth, not as proof your tray has a named disease.
Can I prick them out of a shared tray?
You can, and you will wish you had used deep cells. Eucalyptus resents root damage. Sow one to a module or root trainer so the first move is a whole root ball into a slightly larger pot. A shared tray looks efficient until the roots knit and you tear them.
What if nothing comes up after a month?
Check depth, water and temperature before you blame the whole packet. For a hardy sowing that has sat four to six weeks with no seedlings, a cold stratification and a fresh attempt is the Chiltern-style rescue, not a guarantee. We are not stating a germination percentage for any listing in this comparison.
Is the compost in the SAFLAX box enough on its own?
The £5.25 kit includes coconut-fibre substrate for the 100 seeds. Use it as the fine sowing mix it claims to be. It does not feed a tree for years, and it does not change the species. The £4.55 packet is the same blue gum name without that fibre, so you supply your own peat-free compost.

Related pages

Eucalyptus seeds buying guide

Eucalyptus seeds for pots

Hardy eucalyptus seeds

Eucalyptus seeds

Best eucalyptus seeds: H5 parvula or the H3 blue gum

Sources

Public UK sources named below. amazon.co.uk prices, stars and review counts on these twelve listings were read on 19 October 2026. Page updated 21 October 2026.

  1. RHS eucalyptus growing guide (retrieved 19 October 2026)
  2. RHS Eucalyptus gunnii (retrieved 19 October 2026)
  3. RHS Eucalyptus globulus (retrieved 19 October 2026)
  4. RHS Eucalyptus parvula (retrieved 19 October 2026)
  5. RHS Eucalyptus camaldulensis (retrieved 19 October 2026)
  6. Forest Research cider gum (retrieved 19 October 2026)
  7. GOV.UK invasive non-native plants (retrieved 19 October 2026)
  8. ASPCA eucalyptus (retrieved 19 October 2026)