Rainbow Eucalyptus, Mindanao Gum (Eucalyptus deglupta)

Looking for Eucalyptus deglupta seeds? Click here to buy on eBay!!

UPDATE! 2014/03/06 – This is the harvest time for Eucalyptus deglupta and we are doing are best in collaboration with our seed merchants, to acquire a large quantity of Eucalyptus deglupta seed in the coming weeks. Watch this space for updates!

Eucalyptus deglupta Blume is a huge evergreen tree from the seasonally-wet humid tropics. Indigenous to Indonesia, Papua New Guinea and the southern Philippines, it grows to more than 65m (213ft) and upwards of 2m (6.5ft) in diameter. Away from its natural environment it rarely exceeds half this size.

It is the world’s fastest-growing forestry tree, cultivated mainly for pulpwood on plantations throughout the tropics. It also provides a source of hardwood timber for use in cabinet-making, construction and joinery. In the Philippines the even-textured wood is known as “Bagras” or Southern Mahogany and in Papua New Guinea, “Kamarere” is a major export timber. E. deglupta is one of four eucalypt species not endemic to Australia, and is the only eucalypt to occur naturally in the northern hemisphere.

As an ornamental specimen, E. deglupta is popularly admired for its multi-coloured “painted” appearance, from whence the common name, “Rainbow Eucalyptus” originated. Fine layers of bark exuviate in strips of varying shape and size, revealing a smooth, white to pale green surface, which with age turns to vibrant green, grey, pink, red, orange, blue, and purple. The rainbow effect is most impressive on habitat specimens, and tends to diminish the further the tree is found growing from the tropics.

Cultivation outside the tropics

In less favourable regions, a degree of cold tolerance can be expected, perhaps even enduring an overnight frost. However, E. deglupta is unlikely to survive prolonged exposure to sub-zero temperatures. In Mediterranean climates with plentiful irrigation and sunshine, new growth will emerge almost year-round. Some foliage burn is inevitable on young saplings where low temperatures of 4°-5° Celsius (39°-41°F) are expected. The juvenile leaves are soft and tender, and damage easily during the first year when planted out.

By the second summer Eucalyptus deglupta develops adult foliage. Once delicate, velvety leaves now emerge a lighter shade of green, turning a lot thicker, with a  glossy appearance. During this period, the incredible growth rate becomes apparent. The tree in the adjacent photo is perhaps the first Eucalyptus deglupta in mainland Spain. At 1.5m (5ft) tall, planted out in May 2010, it had already doubled in height by the end of October the same year. All that is required to maintain this rate of growth is full sun and plenty of water!

About the seeds

The seeds are tiny, measuring approximately 2mm x 1mm*. There are an estimated two million seeds per kilo, or 2000 seeds/g. From my own experience, I believe this figure is based upon seed volume alone. Harvested seed of E. deglupta is inseparable from the chaff, and since the amount of chaff varies from one batch to another, this would in turn influence the total seed volume.

* shown with metric scale (mm)

I sell Eucalyptus deglupta seed in 0.25, 0.5g and 1.0g quantities, allowing a 30%-40% margin for chaff. Taking into account a field germination rate of 60%, I equate this to roughly 300-400 viable seeds per 0.5g packet. This sounds more than enough for the average grower, but E. deglupta is fickle in the early stages. Additionally, when sowing an entire 0.5g packet of seed, expect around 10-20% of the tiny seedlings to damp-off after the first few weeks. Make sure you observe the highest standards of greenhouse hygiene when sowing and cultivating E. deglupta seedlings.

Of the seedlings that survive, many will remain undersized. At least half will make the grade and require pricking out and potting up ahead of the rest. If germination yields the best results, and you’re only interested in the strongest plants, then expect around 100-150 seedlings from a 0.5g packet of seed. If all you require is a few plants, read on. Throughout the early stages of growth there will be setbacks, and these will be discussed in detail.

Germination method

Seeds germinate readily in 4-8 days. To maintain viability, make sure you keep the seeds dry, and refrigerated at around 3°-5° Celsius (37°-41°F). This will extend their lifespan by a considerable number of years.

Every gardener has their own technique for sowing seeds. Even so, I  am often asked about the best method  for germinating E. deglupta. As I mentioned earlier, this is a very fickle plant to raise from seed, and the first few weeks will seem painfully slow by comparison. Living in the Mediterranean, I find the best time of year to start is in April.

I prefer to use a lightweight sterile medium such as vermiculite, sometimes mixed 50/50 with coir (coco-fibre). Similarly, you can use perlite mixed with regular compost. Both are fast-draining. More importantly, these loose mediums will not form a “crust” once watered. This is critical, as the emergent seedlings can easily become trapped under the surface.

I typically germinate 0.5g of E. deglupta seed in white, semi-opaque, plastic trays measuring approx. 30 cm x 18 cm x 6 cm (12″ x 7″ x 2″) deep. I use a second tray as a lid to maintain humidity. Air flow is beneficial, so a loose-fitting cover which lets light through is ideal. Bright light, natural or otherwise, is sufficient during the early stages of germination. Full sun is only necessary once the seedlings are at least 5 cm (2″) tall and ready for pricking out.

The importance of cleanliness cannot be stressed enough. Make sure your germination containers are cleaned and sterilized. Use only fresh, quality compost if you prefer using soil, and use only clean water in you mix.

Fill a tray to about 3-5cm (1″-2″) with lightly moist germination mix. Level it smooth but do not compress the mix. Then sprinkle the seeds evenly over the surface a pinch at a time. Use a hand-held spray bottle to wet the seeds down. I add soluble, organic seaweed fertilizer to the water when using a sterile mix, as the tiny seeds hold very little nutrition. Now sprinkle some more of the medium over the seeds, just enough to cover them. Finally, water well, but do not soak. Cover the tray for up to 12 hours a day, and maintain a good level of light, with temperatures between 20°-30° C (68°-86°F).

Keep the mix moist, and do not let it dry out. If the temperature is consistently above 30°C (86°F) it is better to have the mix wet, even to the point of saturation. At this temperature, the emerging seedlings will tolerate a wet germination medium. Finally, do not despair if after your seedlings have sprouted, they appear to stay the same size for several weeks!

Sowing your E. deglupta in early April means they will be ready for pricking out in less time than if you sow them in February or March. Any time of the year will do, as they’ll happily survive lows of  4°-5° Celsius (39°-41°F) in a dormant state. If you like to see steady progress however, it is better to wait for the onset of Spring.

6 weeks later..

Around this time you can prick out the biggest seedlings and pot them up. Pricking out is not difficult, just hold the stem with thumb and forefinger and pull gently upwards. It helps to use a fine point to dig below the roots as you lift the seedling. For successful transplanting, try to transplant after sundown when the air is cool. I use plug trays, and a soil mix that is just dry enough to stir up finely. Ensure the seedling is upright, and that there is no air around the roots, by watering in well.

In practical terms, this is the earliest stage at which you can pot up E. deglupta seedlings, and it calls for a steady hand! If you are sowing fewer seeds using a bigger tray, then you can wait a few more weeks, until the seedlings are at least 5 cm (2″) tall.

Your newly transplanted seedlings, after watering in well, need be incubated in a covered box immediately. Keep them in the shade at around 20-25 Celsius (68-77 F) for at least 3 days. Many will wilt as a result of transplant shock during the first couple of days, but 80-90% of them should bounce back. After this time you can keep them uncovered, preferably in a greenhouse. If you live in an area of low humidity, it is best to keep your seedlings covered until you can visibly see new growth. Make sure they receive plenty of all-round light, as they are very responsive to the angle of sun.

Week 10

By mid-summer your seedlings should be enjoying the outdoors. Now almost 7 cm (3″) tall, they will have doubled in size from when they were pricked out. Make sure they are sheltered from strong winds, as they blow over easily. They are somewhat top-heavy at this stage, and until the stems turn woody, they will want to lie flat even in light gusts of wind, and invariably they will grow crooked rather than straighten up.

You may decide that this is a more manageable size at which to prick out your E. deglupta seedlings, in which case you should still follow the same procedure for incubating against transplant shock. The only difference being, that you should not pot them up into plug trays like these shown here.

The root growth on E. deglupta is phenomenal, the equivalent of a weed. Furthermore, and this is true for all eucalypts, they really do not perform well in pots. From this stage onwards, the growth rate is determined purely by how much root space each plant is given. In 5 or 6 more weeks, these little seedlings can be popped out of their trays and potted up into any size pot, preferably no smaller than 2 litres (0.5 US gallons).

Week 17

 

 

If you have plenty of spare seedlings, try experimenting with different-sized pots, and you’ll be amazed at the difference in growth rate! The ideal size for planting out is any time from 17 weeks, up to a year old. After that time, any manageable-sized container will soon start to restrict growth. Aim to have your Rainbow Eucalyptus  planted out before the second growing season commences.

If you don’t have a garden, did you know that E. deglupta make excellent bonsai specimens? Even when planted out, if space is an issue you can prune a young E. deglupta sapling into a shrub, to create a ‘large bonsai’. Although it is the rainbow-coloured trunk that attracts most attention, it is the newly emerging foliage that is prettiest.

Pests and diseases

E. deglupta seedlings are easily plagued by aphids, which are little more than a nuisance. However, there is a leaf blight that affects this eucalypt, of which I still know little about. It can appear on the tiniest of seedlings as small red dots and quickly spread, eventually killing an entire batch of plants. What is puzzling, is that it seems to live on some seedlings without affecting their health.

The best advice is to dispose of affected seedlings by burning, ensure good ventilation, and separate your seedlings into small groups. The blight will only kill seedlings up to about 6 months, after which time it seems to pose no major threat. Remnants of the blight are just visible in an earlier photo here.

About princeofpalms

My main interest is the cultivation of rare and exotic palms. I am regular contributor to the International Palm Society forum "PalmTalk" and the European Palm Society.
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38 Responses to Rainbow Eucalyptus, Mindanao Gum (Eucalyptus deglupta)

  1. Robert Phillips says:

    Hi,
    I ended up finding six rainbow eucalyptus tree in Australia but before I found out what was attaching them stripping the leaves and snaping the stems I lost three of them. It was possums. I have protected the other three trees and two of them are about 3 metres high. I amd also sowing Foxtail palms that have seeded growing in my yard and have got 30 of them shooting. I have attached a photo of my rainbows at the front entry. It looks like I can not attach the photo. I have also planted about 100 seeds tonight of the Rainbow eucalyptus, just brushing up on you recomendations. Regards Robert

  2. Sent you an email, Trish.

  3. Trish says:

    Hello John, thanks for the helpful info on your site. I would like to purchase and plant E.deglupta but cannot find anyone in Australia.

  4. Just click on the link to eBay at the top of the page!

  5. Chanelle says:

    I live in Australia and I’ve been looking for these seeds for such a long time,do you know where I can buy any? Thanks

  6. Sorry for your losses there, Ron. Agree, although your humidity is a bonus in the long run. Well, here in Spain, it’s almost a losing battle pricking out and getting them to survive without some sort of humidity chamber for a few days. I’m trying this year without, and only a select few seedlings seem to take, despite each seedling getting the exact same treatment.

  7. Ron says:

    Left them covered too long and they molded. So humid here that don’t need covers (should have followed the instructions better). Still have about 50 seedlings that survived but will give it another shot.

  8. In the first instance, your Eucalyptus deglupta will reveal a bright green stem, when the trunk is just a few inches in diameter, and the tree some 20 ft tall. Since the exfoliated strips are proportionally larger at a younger age, there is little variation in colour. The tones will be less vibrant too, if you live outside of the tropics. Bright green, dark ochre/red and a bluish-grey dominate for the first few years, starting at around 4-5 years planted out. I hope that answers your question!

  9. J Rodriguez says:

    First, thank you for the awesome site ! I just have a quick question before I decide whether or not to get involved in planting this tree. How long before the rainbow bark starts to show? Thanks in advance

    -JR

  10. Thanks Ron! Growing Eucalyptus deglupta in S. Florida is a bonus for you. When pricking out seedlings, they really benefit from high humidity to overcome the transplant shock. Where there is less humidity, such as here in Spain, I make sure to mist the greenhouse and keep my seedlings on the floor out of direct light, and if possible at a temperature below 25 Celsius, until they bounce back.

  11. Ron says:

    About one week out from planting as instructed and have hundreds of germinated seeds. These really are top quality seeds as I have had poor success in the past. Thanks and I will follow your blog closely. I am in South Florida where it is very warm (near 90 every day and only down to about 77 at night).

  12. Please see the link to eBay at the top of the page. There are 3 pricing options available. Quotes for bulk orders are also available upon request.

  13. Leon says:

    I would like to purchase seeds. Do you still have them available and if so, what is the pricing?

  14. Julie Nolan says:

    Just got my seeds and am off to plant them. I have purchased two plants of this online and killed them both. Not enough water I’m sure.
    This is a great tutorial! I’m sure your words will help!

  15. Hi Robert, sent you an email.

  16. Robert Phillips says:

    Hi,
    I live in Australia and have had problems finding Rainbow Eucalyptus trees or seeds I have some coming from a kind person in another state in Australia and picking up four trees that are about a metre high. I would love any ifo on looking after them as I first saw them in Hawaii and fell in love with them.
    Robert

  17. Pete N. says:

    Thanks for your reply.

    Should I continue suppling the same level of humidity to the seedlings until they are transplanted? e.g. Could it hurt the young plants if it is really humid in the aquarium?

  18. Thanks for the compliment! Much appreciated.

  19. Sounds like an ideal set-up. You really only need to keep the seeds covered for the first week or so, until most of the seeds have germinated. I have found that fungus spores will develop on the surface of the growing medium after the first week, if kept enclosed for more than 12 hours a day (I believe the pathogens to be in the chaff). Once you have sprouts, the light is all important, so your lamps will be a great bonus. With an open container, good humidity/temps and round-the-clock, direct light source, you probably have the optimum conditions already.

  20. Pete N. says:

    I planted the seeds 1 week ago. Over 50% appear to have germinated so far.
    I’m growing them in Perlite, and have added Schultz 10-15-10 plant food to the water (the amount recommended for house plants).
    I have a 60 gallon aquarium that I wasn’t using so I’m growing them in there. I’m also using a submersible aquarium heater, in a 2 quart pan of water, to help heat the aquarium…. I’m hoping this will eliminate the need to cover the seedling tray, in that this heater/water combination appears to be producing quite a bit of humidity.
    I’m keeping a 50 watt grow-light on 24/7, just outside of the aquarium.
    The interior heat of the aquarium seems to range between 73 to 81 °F .

    Any suggestions?

  21. sherizona says:

    I planted your rainbow seeds recently and within a few days had several tiny sprouts. Great product, thanks for the tutorial. So many people don’t realize how important it is to have sterile soil so the bacteria doesn’t consume the seed. Looking forward to watching these little guys take off!

  22. My pleasure, Cory!

  23. Cory Fink says:

    Got my seeds today, very excited to start the process. Thanks so much for this awesome website, and the future help :)

  24. Matt Bradford says:

    Great info John! I followed your instructions and had incredible success. Thanks for your generosity. It’s people like you that make this world fun to be in.

  25. Hey Walter, sent you an email.

  26. Happy to link up with other bloggers. Thanks for the compliment.

  27. Admiring the dedication you put into your website and in depth information you provide. It’s great to come across a blog every once in a while that isn’t the same old rehashed information. Excellent read! I’ve bookmarked your site and I’m including your RSS feeds to my Google account.

  28. Walter says:

    Hi again, I just received my Algae 600, how do you preared it?, how much concentration do you used? Thanks!

  29. Thanks Mike! I appreciate the feedback.

  30. mikeross says:

    This is such a great resource that you are providing and you give it away for free. I enjoy seeing websites that understand the value of providing a prime resource for free. I truly loved reading your post. Thanks!

  31. Happy to hear about your successes, Walter! The seaweed fertilizer I use (spec sheet) can be found here: Alga600 Organic Fertiliser. It’s a UK website, but I’m sure you’ll find a similar, local supplier. Regards, John

  32. Walter says:

    Amazing how good the seeds are, I had at least 95% germination in just 2-3 days, really satisfied, hope at least half grow large enough to pot them. Just a question, which mix of nutritional compenents did the organic seaweed fertilizer that you used or recommend (mix of P, N, etc). Thanks. Best regards.

  33. Glad to be of help, Bill!

  34. bill burnaugh says:

    Hello, me again.I recently sent you an e mail on how to increase germination on E.deglupta.I read your blog and found it very interesting.My recent trip to Thailand I had a 90 percent mortality rate but now know what I did wrong !! I assumed a constant “Wet” was causing damp off so I held back on watering…Im headed to Mexico in a month and will try your method with the remaining seed.I first saw this tree in a botanical garden in Hawaii about 5 years ago and had to have one.ha ha I have 2 trees in Mex that I started from seed.They are about 40 ft tall now.Id like more in Mexico and some in Thailand as they are show stoppers!!! Im a member of the IPS as well,We have about 800 palms under cultivation in Mexico and half that in Thailand ( but much more in the future) We spend about 8 months of the year farming in Thailand and Mexico. bill Carson City,Nevada USA ,Baja California Sur Mexico, and Nakhonsawan Thailand

  35. jaime says:

    I just place an order on daves garden site for 2 packets of seeds.
    If i buy more I will get a better price?
    how long can the seeds last stored?
    Thanks

  36. Contact me any time regarding seeds. I also offer larger quantities with a discount. Use the contact form when you are ready. Regards, John

  37. David Apswoude says:

    Informative, clear and concise growing guide.. Thank you.. I would like you to supply seed packets to Australia, John, as I intend planting out a 2 kilometre boundary line with Rainbow/ Deglupta Eucalypts at my farm..

  38. pamela wilson says:

    Interesting and informative article John if people follow this they cannot go wrong !!!