2022 Drought

 Drought in 2022. Part 1

I am starting to write this on 27th July 2022. A bit after England recorded 40 degrees C for the first time at Coningsby a mere 14 miles East of here on the 19th. There has been below average rainfall each month this year and almost none since March. I have been giving the newly planted trees at Pit wood a splash of water Occasionally. It is unrealistic to water any properly. Since the start of July some of the 10 year old trees in the rectangular field have been wilting particularly those near the track by the ditch. 

A view of the southside of the rectangular field. Dead looking Rowan and a severely wilted sweet Chestnut.

All the Rowan around the field have red berries and only brown leaves. Rowan as its name Mountain Ash implies is a tree of mountains and high rainfall. Some of the sweet chestnut only have brown leaves, and all of them are badly wilted as some are on the Sycamore. This came as more of a surprise, as Mediterranean Trees I expected them to last better. The Robinia are just starting to wilt at the North end of the Field as are the Red Oak.  There is a E.gunnii that has started to wilt. It is the one nearest the corner by the track and the ditch where other trees are struggling. It is the lowest part of the field but appears to dry out first.

The Alders and Aspen do not seem to be badly affected, these are damp loving trees so again a bit of surprise.

Picture of edge of pollarded area in Rectangular Wood into unpollardedd species.

1 Robinia: Only slightly affected by drought. 2 Pollarded Aspen: unaffected. 3 Common Alder: Unaffected. 4. Pawlonia. The only surviving Pawlonia left in the wood. Unaffected. 5. Sweet Chestnut: struggling most leaves brown. 6: An unaffected Eucatyptus in the back ground. 

The trees at Cairn Wood are less stressed on the heavy clay. I think the London Plane, I planted last season, down there have died. At the moment the other trees there look O.K.

The Tulip trees and Coast Redwoods in the Tulip wood at the north end are stressed and have had some water. I lost a number of Douglas Fir in the dry weather in the summer of 2019 on the same side of the wood. More worrying many are a bit limp as are some of the Coast Redwoods that are also 2+years old. A few have died but there is no pattern to their distribution.

The hedgerow trees Hawthorn and Field Maple at Pit Wood particularly the former have plenty of Brown leaves. Ash, Oak, Common Alder, Aspen, Cherry and Holly have appeared to be least affected. I can hear plenty of people saying you should have planted only native trees. There is some justification for this. Trees driven south by the Ice sheets further than the Alps and the Mediterranean will have had to endure drought conditions, as they returned north, because sea levels were very low making sea areas less and colder. The world was very dry when the Ice Sheets were at their peaks.  

Since the extreme heat there has been some drizzle and on the 28th and 1st Aug a couple of millimetres of rain. Some leaves that had started to wilt have recovered but many have died. It will not be till the spring that the affect of the heat and drought can be assessed.  

Weeds

Weeding. 

When seeds are germinating on a woodland floor they need to compete with not only other seeds but also the plants that are already there. Tree seedlings tend to grow more slowly than herbaceous plants and get swamped. When trees are being planted they are usually at least 12" tall they are also normally planted into soil that has been sprayed with herbicide or ploughed. I usually spot spray the places where new trees are to be planted.  Spraying again in the late spring after planting if possible. The idea being to reduce competition for water and nutrients.

Spot spraying of newly planted trees at Pit Wood. An almost ideal mown flat grass meadow. Planting into a woodland presents different problems.

The problems associated with mature weed beds is the competition for light from tall perennial weeds and shrubs. 

This picture shows the trees that were planted over the winter of 2020/21 in the Plantation, which I now call the Tulip wood. The new trees are where the canes and tree guards are.  On the right the original sprayed area, around a tree, can be made out but the tree is not as tall as the weeds.

Both Woods are on nutrient rich soils. Weed growth can be very fast. Here the main weed is goose Grass, which takes over from Hedge Mustard that dominates earlier in the year. As the trees grow they may start casting shade and the dominant weeds will change. I expect Bramble and Nettle to dominate in few years.

If no action is taken then perennial weeds can make walking up the rows difficult. Bramble and Goose Grass can make it impossible. Where trees are newly planted ,I try to keep rows open by brush cutting or spraying. The space between the rows of trees in the photo above will be brush cut. This is quite hard work with Goose Grass being a major component. It wraps round cutter.

The Goose Grass swamping the Coast Redwood in front of the Birch tree will have to be removed by hand.

Where trees have been planted to replace failed ones, control is more difficult. On low nutrient sites the trees can shade out most plants that are not adapted to low light levels. As the trees grow the weeds get less light and tend to grow more slowly.

Once the trees are established I try to keep about one in three rows reasonably clear of weeds to make access easier. This is done by brush cutting and spraying. If there are not pressing reasons to get down between the trees This may not happen with the result that moving through the wood can become very difficult.

I received a pleasant surprise while collecting old spirals in Cairn Wood. The photograph is of a Bee Orchid. To find it was a real shock. It was in a very heavily shaded area and they are flowers of open dry limestone grassland. The heavy clay at Cairn wood was arable before being willow coppice. I will certainly have sprayed the whole field with Glyphosate twice while getting rid of the Willow. There is unlikely to be a Bee Orchid within several miles, so how and why it is here is a complete mystery.  I have pruned back the dense shade around it to give it a chance. It is not normal for me to try to favour plants of no apparent use. It is of little environmental value as the bee it mimics is not in the country, so has to be self pollinating. I will be careful and watchful with weed control now.

Splitting

 Splitting logs.

Wood for burning needs to be dry, this means 20% or less moisture content. Felled trees can be over 60% water. As the bark of a tree is designed to keep moisture in the tree logs dry very slowly and mainly via the cut surfaces.  Logs that have been split can dry much faster. It is easiest to split logs while they are green and recently felled. This is particularly true for Eucalypts. Splitting logs is the most physically demanding and time consuming of all the stages in log production. At least for those of us without expensive automated log splitters.

Logs that have been cut to length dry faster than longer lengths, but they require more handling and are more difficult to store and stack. The compromise I employ is to cut felled trunks  into lengths of 4-5 feet which can fit in the car and then split them. This size is known as cord wood. A cord of wood was the standard measure of fuel logs and is 128 cubic feet, derived from the size of the stacks in which it was initially stacked for drying and selling. A cord being 4' high 4'wide and 8' long.

I start a split using a hatchet placing it where I want the split and hitting it with a lump hammer. Driving the axe head until most of it is in the log. This is not a recommended method as it involves hitting a metal head with a metal hammer. It does require ear defenders and a face protector.

Once the log split opens up Metal wedges are driven into the split. The split should run down the log and release the axe. when the thick end of the wedge is is nearly in the log a second wedge is knocked into the split and the split extended as the first wedge becomes loose and can be relocated further down the the log.

Once the log is split it can be stacked on a pallet at the edge of a wood. It is better to get the log out of the wood where there is more air flow. I often run a Stanley knife blade down the bark. This helps the bark peel away from the log while exposing wood to the air. As it dries under the cut there is variable shrinkage and gaps open in the wood enabling more moisture to escape. 

Felling

 Felling.

One of the troubles with growing Eucalypts is that they can grow very fast. 

Two six year old E. vinimalis blown over winter 2021/2. They have a basal diameter of around 6 inches.

When they are grown amongst other trees they can have root systems not capable of supporting their canopies. They try to get above the other trees and have a high canopy exposed to the wind unprotected by the other trees. If the ground is very wet then the soil has little strength and the trees can be blown over. The situation in the triangular compartment is exacerbated by the high winter water table, which restricts root growth. 

Early 2020  saw storms Brendan, Ciara and Dennis saturate the ground and several of the original Eucalyptus were blown down. The root plate holes were full of water. I had started felling the largest trees for fire wood, but had selected the trees I thought were easiest to fell. At Pit Wood the Eucalypts are in amongst the other trees, and can be very much larger. They risk damaging other trees if they are blown over, or if they are felled. A decision was made to fell larger trees, at least there is the possibility of felling in a direction to minimise collateral damage. 

In the triangular field the largest Eucalypts are from the original planting, so are in recognisable rows and are large enough to need felling. The Eucalypts have strong apical dominance and tend to grow straight up. This means it may be possible to fell in a direction where they will do least damage. When planted in rows it may be possible to fell them all down one side or the other of the row. The picture on the left is of one felled down the middle of the row and balancing on the previously cut stump! 

Because of their apical dominance should they fork then the two limbs grow nearly parallel as in the felled trunk below

The photos above show a forked trunk that has been felled. It can be seen that there is no live wood joining the parts. There is a tendency for one to break in the wind, and then the other. This happened to the post towards the end of the row in the balancing picture above. 

A problem with the different growth rates can be seen in the photo below.

Two Eucalypt pollard stumps can be seen in the front centre of the Photo. They will have been as tall as the as the two Eucalypts with silver trunks and the ones with brown trunks on the far Left at the back. There is a Norway Spruce on the right and a pine stump. These were part of the planting that was mainly felled for the Eucs and conifers to be planted. The Conifers mainly Coast Redwoods are 6-10 foot high while the Eucs were 30-40 ft. The Eucs have been pollarded while they are still relatively manageable and can be felled with little damage to the conifers. They have done their job of providing shelter they now compete with the potential timber trees and will become fuel logs.

Pit Wood History Part II

Pit Wood History Part II 

Planting in  the triangular wood started in March 2011. I had bought some Robinia (also called Black Locust or False Acacia) which I thought were going cheep! There are three large impressive Robinia in Sutton so I thought the climate was OK. They are nitrogen fixers and have a durable timber, so seemed like a useful tree.  There were also a lot of Eucalyptus seedlings, these had been sown and grown under lights over winter. They were in cells and needed potting on. They had been hardening off outside during a mild March and Early April. I decided to plant out rather than pot on. Exactly the same decisions had been made for the same reasons at Cairn Wood in 2010. The result was that a lot of the Eucalypts were not established when there was a sharp frost in May and all the E. nitens, the largest ones needing to be moved on died. A number of other Eucalypts also succumbed to the late frost only a few weeks after planting. I had not learnt  and planted small Eucalypts in April 2011, hoping the lighter soil would allow better root growth. Again all the E. nitens died along with some others but many survived.  

April 2011, the triangular field spot sprayed and  planted up.

There is a ditch along one side of the field, in front of the row of trees, in the top Photo. There was also a single sedge plant towards the corner between the ditch and the track. I assumed that area was the wettest and planted nitrogen fixing alder instead of Robinia and a swamp Eucalypt in the area.

The Triangular field on the 5th May 2011. A sharp air frost has blackened the new growth. The centre row  is ash. The taller trees to the left are Robinia which leafs later. The small Eucalypts to the right were also badly affected. As was the Sweet Chestnut.
  

March and April 2011 were quite after the horrendously cold winter of 2010/11. Trees had flushed early thinking, like me, winter was over. I had planted the whole field by the middle of April.  The -3C frost on May 3rd came out of the blue. The bare rooted trees had to be planted. March is the usual time for spring planting. I can blame the trees for any damage they suffered. The Eucalypts were in cells and could have been potted on or left till mid May. They would have been restricted but alive. A lot of the Eucalypts were lost, The ash and sweet chestnut had their leading shoots killed, so were destined to be forked and poorly shaped trees. Alder are a hardier breed and the Robinia had not come into leaf. The spirals put on to stop the deer browsing kept the frost off the shoots in the spiral.  As there were smaller Eucalypts that had not been planted out I was able to replace losses.

As I write this on 1st May 2022, there are no leaves on any Ash and the Sweet Chestnut is only just breaking bud. (Oak is well out). It has again been a dry warm April, so why the difference I don't know. It could be the micro climate affect of the Spirals. 

There was a fine summer and by August the trees looked well established.

August 17th 2011. The tall trees are Robinia and the dark green showing above black square tree guards are Eucalypts. 

The winter of 2011/12 saw no planting at Pit Wood while  planting at Cairn Wood was completed.  Planting in the Rectangular field waited till 12/13 season. A hay crop was removed from it in 2010, 11, and 12. Meanwhile, the trees grew well in the triangular field except for in an area in the middle of the field.  

Sowing Euc seeds

 Sowing Eucalyptus Seed.

Eucalyptus seeds are small. The picture is of seeds and chaff from the bag shown in the previous post. It should be possible to get thousands of plants from them. They are Eucalyptus glaucescens, this comes with the usual caveat "the maternal parent was predominately" a E. glaucescens. A species that is favoured by the Forestry Commission (F.C.). One of which I am not a huge fan. It has not done particularly well at Cairn Wood or the triangular compartment at Pit Wood. These came from a tree felled in the rectangular area at Pit Wood. They were collected as I had not realised it was a Glaucescens until it was felled and I saw the fruits. It had grown much better than the others growing around it. The problem is probably that the species comes from dry areas and doesn't like my wetter land. Explains why it is better suited to The F.C.  at Thetford, it is also not favoured browse by Deer. 

I sowed some E. viminalis usual caveat on 14th February 2022. Two small tea spoons of seed and chaff were sprinkled onto two small seed trays (8"x6") filled with a multi purpose compost and sand mix. They were worked into the surface with a table fork, watered and left in a propagator, in a plastic bag. As the seed absorbes water it swells and they changes from black to a reddish colour. The close up picture is from the 18th Feb a main root and fine root hairs can be seen. The root tries to get down into soil and the seed is then lifted up, releasing the cotyledons. Once there are signs of sufficient shoots they are taken out of the  plastic bag. 

By Feb 28th ( a fortnight after sowing) the cotyledons were well established. Eucalyptus like most trees are dicots they have two cotyledons the storage structures within the seed. They are not technically leaves. Monocots, with one cotyledon are the grasses and most bulbs.  

By the 10th of March almost all seedlings were showing  their first true leaves. I try to prick out when the true leaves have developed sufficiently to hold while the seedlings are teased out. The largest seedlings get transplanted first, giving more space for the remaining ones. 

The seedlings have been pricked out into plastic 220ml cells.  I  bought this remaining stock from the sole importer of this style at the time and also got some 500ml. cells.  
The Eucs I originally bought came in 110ml cells and I have the cells. Cell grown trees do not normally come with their trays. I was quite fortunate. I think they are too small for Eucs and prefer to plant out larger trees than is done commercially.

  
A hole is made in the middle of the sand compost mix with the end handle a teaspoon and the seedling lowered into it. The spoon is used to press the mix against the root. The gap made is filled with  spoonfulls of more mix. When the tray is complete it is watered.  Afterwards watering is from the bottom, to reduce the chance of damping off, until the seedlings are strong enough to resist the blight. Hopefully when they have 3 or4 pairs of true leaves.

The original seed trays on the 5th April, 7 weeks after sowing. 250 seedlings have been removed. The remaining seedlings are still viable but have grown so large their roots will be so entangled that they will be difficult to tease apart, and will take time to recover.

 

Eucalyptus seed.

 Eucalyptus seed.

There are over 600 species of Eucalyptus. Many montane species or ones from Tasmania can grow well in The United Kingdom. Any generalisations I make about Eucalypts are often made from my own experience of a limited number of species.

The fruits of Eucalypts, called gumnuts, are small woody capsules. They vary in size from that of a small pea to that of a large pea. They ripen at least a year after flowering, so flowers and fruits can be found on the same branch. In the photograph they are the small black dots along some of the bare twigs.  Eucalypts give up on leaves and branches that are not photosynthesising well comparatively quickly. If the base is shaded they grow tall and straight with clear trunks. The photograph is of a branch above 20feet of clear stem.

All gumnuts are fairly similar. The capsules being closed by usually 3 or 4 valves which open as the fruit dries.  The shape of the capsules and the valves is a useful indicator of species as many eucalypts are similar and they do hybridise. 

Some different gumnuts. The 2 black spots above the gunnii and the glaucescens are seeds.
The brown speckling around the gunnii is chaff a padding from inside the capsules. 

 The ideal shape for a eucalypt for fuel logs is tall and thin. This means that seed has to be collected from felled trees or branches cut with a pole saw. I try to collect small branches that have full size green gumnuts and place them in large clear plastic bags. The idea being the seeds can still mature if they are not and the will slowly dry out.  

When the valves start to open I strip the gumnuts off the branches and put them into a small plastic bag to finish drying out and releasing their seed.
The bags get shaken so the seeds and chaff, an inert filler, can fall to the bottom. It is then a mater of separating off the gumnuts. The seeds are tiny and are the black specks. Kept dry they can remain viable for years. The bag probably contains a thousand seeds. The seeds are sold by weight and include some chaff, which is very light.