Mini forests

Mini forests ๐Ÿค” Here in Ireland you can plant up to 0.1 hectares of forest without planning permission. Might not seem like a lot, but it is a reasonable sized mini forest, especially if you are growing Eucalyptus trees.

Let’s put a bit more scale on this. Current recommendations in Ireland are for planting trees at a spacing of 2m, though for Eucalyptus some studies have shown that a spacing of 1.5m gives the best yeild.

Number of trees at a spacing of 2m in 0.247 acres ( 0.1 hectare, or 1000 square metres )

256 trees in total

Bog Lizard - Mini forest 256 trees

Number of trees at a spacing of 1.5m in 0.247 acres ( 0.1 hectare, or 1000 square metres )

441 trees in total

Bog Lizard - Mini forest 441 trees

So how much firewood are you going to get ?

A Eucalyptus tree can reach 15m in 10 years. Around 50 feet. Calculating how much firewood you will harvest will always be an estimate !

Say the base of the tree is 30cm diameter after 10 years, and the height is 13m. This would give a volume of about a third of a cubic metre. Say being ultra conservative that 200 trees make it to this height in 10 years, then 60 cubic metres.

5 cubic metres of ash sees me through a winter easily, but costs around โ‚ฌ500.
60 cubic metres should last me 12 years and 300 Nitens plugs currently costs from around โ‚ฌ900 depending on size.

So planting a mini forest I save at least โ‚ฌ5,000 ! over the 12 years, how cool is that ๐Ÿ˜Ž

NOTE that delivered firewood is not a solid lump of timber, which is how I am basing my calculation. So again I am being ultra conservative.

Other studies have suggested a lower return, though there seems to be limited information available.

An interesting comparison from the Coford report of Sitka Spruce and Eucalyptus Nitens after 13 growing seasons below

 Top height
Picea sitchensis ( Sitka Spruce )11.511
Eucalyptus Nitens22.526
(DBH) Diameter at breast height.

Note also that my cost calculations are for a tree almost half the height that the report compares ! Again I am being ultra conservative, though I am calculating to the base with a diameter of 30cm. Generally I am happy that my calculations are conservative ๐Ÿ™‚
If you take the height of the Eucalyptus to be, say 15m, then perhaps a saving of โ‚ฌ7500 plus, and still erring on the cautious side of the scale.
Are there any other crops which yield around โ‚ฌ1,800 an acre annually without subsidy ?

I am into my third year of growing Eucalyptus and if you intend to grow for firewood, then Nitens, Globulus, Dalrympleana and Johnstonii would be my current picks. I’ve also found MacArthurii to be wind resilient, the only real issue I’ve found here in West Clare.
Eucalyptus Gunnii are fast growing and great for coppicing. Viminalis are very fast when given a bit of shelter while they establish and until their foliage hardens, their growth can be hampered by wind burn.
All trees harden and acclimatise with maturity.
Most Eucalyptus produce good quality firewood, though some varieties are more suitable than others. I’ve detailed which are best on the specific pages.

If you have enough land and want to plant a bit more than a mini forest, then grant aid may be available for planting Eucalyptus here in Ireland.

Some further scientific reading which generally supports my claims:


Perhaps because I was new to Ireland, stoves, indoor fires, turf and firewood, my focus has been bias towards planting Eucalyptus mini forests for firewood, though the more I research the more I am keener on growing mini forests for other reasons. Agroforestry being one.

There’s a definite hostility where I live to forestry.
It’s understandable, historical plundering of Irish forests by the Tudors and subsequent poor legislation that discouraged support for forestry.
Hopefully I can change a few minds.

Anyways, here is a photo of a popular variety of Eucalyptus planted here in Ireland. Eucalyptus Dalrympleana. A wind tolerant shelter providing tree. I note the cattle always try to shelter from wind and rain just as humans and other animals do.
Oh, and also the scorching sun โ˜€๏ธ

A fine looking mini forest, even if this one is probably natural. Photo by Ian Sutton A high resolution good quality photo if you want to follow the link.

Dalrympleana mountain gum forest

Mini Forests

If you have even a quarter of an acre of land available to plant trees, you can gain from planting Eucalyptus.

Personally my acre was mostly planted with grass, and cutting it with the walk behind was quite amusing to start with, but I soon tired of the six kilometre walk.

Many of the houses I see around where I am in West Clare have gardens that are predominantly lawn and I doubt this is unusual for the rest of rural Ireland. What a waste when they could be planting mini forests. Even if it is just to attract wildlife. Eucalyputs flowers will attract bees and other insects which will attract birds and other wildlife, another benefit of planting mini forests ๐Ÿ˜‰

Mini forests for your own personal supply of constructional timber ๐Ÿค”

Personally I think it would be great in these times where the effects of global warming are becoming increasingly apparent if grant aid was made available to smaller land holders of which there are many in Ireland to plant mini forests and help achieve carbon neutrality. Eucalyputs grow faster than most other species, so planting Eucalyputs mini forests would a grand thing to do, not just for you, but for your family and your future generations as well ๐Ÿ˜‰


I am very much at the beginning of experimenting with Paulownia as a mini forest, though I am confident of my figures and assuming they grow at even half the rate of those in the Far East, Eastern and Southern Europe where there is significant commercial interest and extensive planting, then I will be happy with the return on my outlays.

Besides the coppiced logs, if left to grow on, then a better return can be made from their use as constructional timber. As with Eucalyputs you won’t have long to wait, Paulownia can grow at up to four metres per year in Germany, so it’s very possible they may manage three here in Ireland ๐Ÿ˜ฎ

Besides the aesthetics, a Paulownia mini forest will provide:

  • Good bee and insect food when they flower in early spring, though flowering may only commence from around year three.
  • Shelter, and they have been used to very good effect in rural China as shelter, improving crop yields significantly.
  • Shade for livestock.
  • If you keep free range chickens, then converting to agroforestry with Paulownia is considered to be one of the most profitable uses of an acre of ground.

Here are my mini forest figures for my 0.03 of an acre:

  • Cost of Paulownia Trees – โ‚ฌ292
  • Fertiliser, Milk Kefir, Mycorrhizal Fungi – โ‚ฌ5

Total around โ‚ฌ300

Estimated return after 11 years – โ‚ฌ808
NOTE I am not including processing costs, though these on my personal mini Paulownia forest are offset by not having to cut the fecking grass ๐Ÿ˜…

Return calculated on a tonne bag of firewood costing around โ‚ฌ80, if prices rise as they are likely to do now that turf cutting is banned, then the ROI will be greater.

Paulownia does initially have a high moisture content and will require drying before burning. It is however less dense than most hardwoods and will dry more quickly.
I say the above as there’s a lot of misleading information about Paulownia as a source of sustainable heating fuel. It has and is used in Asia and Africa as a source of firewood.

Figures are per tonne bag

Year 1Growing
Year 2Growing
Year 30.6
Year 40.8
Year 51.1
Year 60.8
Year 71.1
Year 81.4
Year 91.1
Year 101.4
Year 111.8

NOTE I have not verified the figures below ! they were posted on Social Media ! so caution should be exercised. Nonetheless, continental Europe are ramping up their planting of fast growing valuable Paulownia hybrids, and I very much doubt the often large corporations involved will be doing it just because it’s fashionable ๐Ÿ˜‰

I also saw one post on social media where the ROI for Paulownia growing in Albania was the equivalent of โ‚ฌ5000 per annum, the crop being 160 trees selling for โ‚ฌ35,000 after seven years ๐Ÿ˜ฎ

Below is a to scale representation of 169 trees with 3.5m crowns, effectively a spacing of 3.5m between trees.

Bog Lizard - Paulownia mini forest on an acre

NOTE Paulownia aren’t a tree for the bog !
They like a lot of hydration, but don’t like having their roots constantly saturated. My current observations from the cold damp 20 / 21 winter is that they survived the frosts with ease, though didn’t enjoy the constant soakings. I lost a couple out of perhaps a hundred. I would think that rather than them actually failing completely in cold damp saturated ground, growth rates would decrease.
If you have some free draining ground then I would definitely recommend trialing Paulownia as a mini forest / tree farming here in Ireland. The risk / reward ratio is weighted so heavily in favour, i.e. a very small outlay for a possible very large return ๐Ÿ˜‰

The other aspect of growing Paulownia is that they are very well suited to agroforestry, apparently particularly rearing free range chickens for egg production. Teagasc suggests no more than 400 hens per acre, lets be conservative, 200 hens.

  • 200 eggs per day, lets say 100 to be conservative
  • I buy a carton of six organic eggs for โ‚ฌ1.99, say you get a third of that at wholesale, 11 cents an egg.

So โ‚ฌ8000 a year from egg production per acre less costs:

  • Setting up
  • Additional feed
  • Vetenary
  • Admin costs
  • Wage costs

Lets be conservative again and allow for a third as net profit โ‚ฌ2650

So in total per acre โ‚ฌ2650 + โ‚ฌ5000 = โ‚ฌ7650 per year.

Assuming the first year is non productive, being set up time, then we can take an eight year cycle.
Estimated Profit per year:

โ‚ฌ6085 per year of the eight year period and Paulownia will regenerate from the stump and its considered you will get three rotations before having to replant.
So for the second and third cycles are seven year with a profit of โ‚ฌ7650 per year.

NOTE my figures are educated guesstimates, though also NOTE I am being ultra conservative.

Certainly if you have some suitable land for tree farming, both Paulownia and Eucalyptus mini forests and agroforestry are worth trialing.
What have you got to lose ๐Ÿค” the worst case scenario is that you grow; in the case of Eucalyptus, a lot of high quality, high value firewood and in the case of Paulownia a lot of medium quality firewood (by BTU)