Mini Forests


Mini Forests 🤔

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

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

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 €500.
60 cubic metres should last me 12 years and 300 Nitens plugs currently costs from around €900 depending on size.

So planting a mini forest I save at least €5,000 ! over the 12 years, how cool is that 😎

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


Tree Species
Top height (m)DBH (cm)
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 🙂
If you take the height of the Eucalyptus to be, say 15m, then perhaps a saving of €7500 plus, and still erring on the cautious side of the scale.

Are there any other crops which yield €1,800 per acre annually without subsidy 🤔

I am into my Sixth year of growing Eucalyptus and if you intend to grow for firewood, then my picks would be:

  • Nitens – fast growing, wind resilient.
  • Globulus – fast growing, wind resilient.
  • Dalrympleana – wind and frost resilient
  • Rodwayi – grown commercially for firewood, can be coppiced. Very wind resilient and frost hardy
  • 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. Frost hardy.

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.

Some further scientific reading which generally supports my claims:

Agroforestry

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.

Dalrympleana mountain gum forest

Eucalyptus 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 large 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 😉

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. Eucalyptus grow faster than most other species, so planting Eucalyptus mini forests would a grand thing to do, not just for you, but for your family and your future generations as well 😉

Paulownia Mini Forests

As with most of my Mini Forest, the main incentive was firewood, and from research over the past few years, its’ currently May 2024, Paulownia wood does make good firewood, though the caveat is that it has a high combustion temperature. It takes a lot of heat to get it to burn in the first place. Not an issue if you set your fire with a mixture that contains Eucalyptus, which has a very low combustion temperature.

So not the miracle tree I’d hoped for 😏 though others in Ireland have had growth rates of 3m per year in sunnier locations.

I’m still a fan, a neighbour a few kilometers away has a couple that flower prolifically, so I should get the beautiful purple flowers in a year or two.

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.

For me there will be an additional benefit, I won’t have to cut the grass on a steep bank, the micro Paulownia forest will look better and provide more habitat and bee fodder 🐝