treeblog - Archive - October 2009

On Saturday the 12th of September I went for a late summer’s wander with my father. The weather was beautiful, the scenery was stunning, and our route just happened to pass by a couple of special trees: two rowans from which we collected berries to plant for treeblog’s Set D, one on Whitwell Moor and one overlooking Oaken Clough high up in the Ewden Valley.

I previously collected berries from the Whitwell Moor rowan in autumn 2008 which I planted as part of treeblog Set C this spring (along with berries from another rowan, downy birch seeds, and sweet chestnuts), then replanted as Set C-r on the 12th of May. None of those seeds have germinated to date, presumably because I never pretreated them before planting them - something I didn’t realise was necessary. Without the pretreatment they still ought to germinate, but a whole year later rather than in the same year like I expected. So treeblog is expecting rowans from both Set C and Set D to germinate in spring 2010!

The Whitwell Moor rowan on the day of my Set D berry collection: the 12th of September 2009.

I discovered the Oaken Clough rowan this summer on the 18th of July. When I first lay peepers on it I knew that it had the biggest girth of any rowan I’d ever seen. I measured it on the berry run: 3.4 m (11 ft 2 in.) in circumference at about shin height. That gives a diameter of 1.1 m (3 ft 7 in.). These figures might not sound very impressive, but for a rowan they are well impressive. Unfortunately, this monster of a rowan has suffered a catastrophic collapse. Most of the collapsed boughs nevertheless remain alive, and since this incident the tree has put out a lot of new growth. There’s no reason why it shouldn’t keep on going for many years to come.

After I’d picked my berries, I sort of forgot about them for a couple of weeks. I just couldn’t stomach the upcoming task…

The Oaken Clough rowan berries. The black ones have gone bad. [Photo: 20 Sep. ‘09].

Then last week I got around to removing the seeds from the berries. This was a long, time-consuming process. I estimate it took me four or five hours, and that was only working with about half of the berries! The other half had gone rotten because I’d waited so long to act. I should have removed all of the seeds when the berries were fresh, but then ten hours of seed extraction would have sent me pathologically insane. Whatever, the outcome is I have plenty of seeds.

This afternoon I removed any bits of husk still attached to the seeds. How nice and clean they look!

The clean extracted rowan seeds earlier today. The Oaken Clough rowan’s seeds appear to be slightly larger than those of the Whitwell Moor rowan.

Right. Now the seeds are all ready for pretreatment. To improve my chances of Set D success, I’ll be trying out not one, not two, but three methods of pretreatment. My two piles of seeds will be split into thirds, and each pair of thirds will undergo a different method of pretreatment. These methods are laid out in a Forestry Commission practice guide, and an upcoming post will detail what they are. The pretreatment has actually already begun for one pair of thirds: they are currently being soaked for 48 hours to rinse off any germination-inhibiting chemicals!

N.B. As each of the three Set D species are being planted on different days, I’m going to describe the rowans as belonging to Set D-r, the beeches – which were planted on Wednesday - as belonging to Set D-b, and the sweet chestnuts – which I have yet to collect – as belonging to Set D-c. That’s just to make things easier when I say blah blah blah Set D-r, Day XX.

The fortieth edition of the Festival of the Trees is over at local ecologist. Go read!

Two species of caterpillar on the grey alders

Earlier this afternoon I noticed several caterpillars on two of the Set A grey alders (Alnus incana). There were a few colourful caterpillars munching away on grey alder No. 3 and there were several white “snowflakey” caterpillars on grey alder No. 2. These snowflake caterpillars have been on the alders since at least mid-August and they seem to have some kind of magic power that can prevent a camera from focussing on them. They eat in random patches to leave the leaves full of holes like a Swiss cheese whereas the colourful, curly caterpillars eat in a more systematic fashion, devouring neat sections between veins. These caterpillars stand with their tails sticking up into the air; when I got close to them they gave them a little wave.

Last year there were two or three other species of caterpillar on the alders. Have a look at all the posts tagged with ‘caterpillars’ if you’re interested!

By the way, I’ve no idea what species either of these caterpillars belong to. Leave a comment or drop me an email if you know what they are, please!

Update (July 2010): The black and yellow ‘caterpillars’ are actually larval forms of the hazel or birch sawfly (Croesus septentrionalis).

Of Arcite’s funeral (A Knight’s Tale)

High labour and full greet apparailinge
Was at the service and the fire-makinge,
That with his greene top the heaven raughte,
And twenty fadme of brede the armes straughte –
That is to sayn, the boughes were so brode.
Of stree first there was laid many a lode;
But how the fire was maked upon highte,
Ne eek the names how the trees highte
(As ook, fir, birch, asp, alder, holm, popler,
Willow, elm, plane, ash, box, chestain, linde, laurer,
Maple, thorn, beech, hasel, ew, whippletree)
How they were feld shall not been told for me;
Ne how the goddes runnen up and down,
Disherited of hir habitacioun
In which they woneden in rest and pees –
Nymphes, faunes, and hamadryades;
Ne how the beestes and the brides alle
Fledden for fere whan the wood was falle;
Ne how the ground aghast was of the light,
That was not wont to seen the sunne bright;

From The Canterbury Tales by Geoffrey Chaucer.

Set D: sweet chestnuts collected & planted

Three sweet chestnuts sitting in an opened cupule. The dead catkin that held the male flowers, still attached to the base of the cupule (which once was a female flower), can be seen in the background. [Photo: 8 Oct. ‘09]

Last Thursday (the 8th of October) I went on a tree mission to Wigtwizzle with my sister. Mission objective: to collect nuts from the massive sweet chestnut (Castanea sativa) there for treeblog Set D.

While a lot of unripe cupules were stillon the tree, a great many ripe ones were lying open on the ground below. While trying to avoid a nettling, I managed to gather a haul of chestnuts with a total fresh weight of 75 g (2 ½ oz). Mission accomplished!

I collected nuts from the same tree in 2007 and 2008 for Set B and Set C respectively, but I didn’t manage to grow a single seedling. I now know the error of my bad old ways; I erred by waiting until spring before planting, by which time the chestnuts – which lose moisture rapidly and so are unsuited to storage – would have been well and truly dessicated. This time around, with only two days passing between collection and planting, treeblog might finally produce some baby sweet chestnuts.

I planted one hundred of the nuts yesterday in five forty-individual-pockets-to-a-tray seed trays using a special seeds and cuttings compost from B&Q. I ran out of room (and out of compost), so I had about sixty nuts left over. Until I decide what to do with them, I’ve mixed ‘em with some damp compost and popped ‘em in a plastic bag.

One of the seed trays showing forty chestnuts in forty ‘pockets’: a planting action shot.

The final product: five seed trays with one hundred sweet chestnuts carefully picked and planted. This is treeblog Set D(c) - the chestnut part of Set D. Set D(b) – the beech part – was planted on the 30th of September and the rowan seeds – Set D(r) – have just begun pretreatment and are on schedule for a springtime planting.

treeblog Set D: pretreatment of the rowan seed

So I’ve (1) collected and (2) pre-pretreated treeblog’s Set D rowan seeds. Now they are undergoing (3) pretreatment before I (4) plant them in the spring. The last time I planted rowan seeds – for treeblog Set C – I neglected to pretreat them and my folly was rewarded by a total absence of germination. (So far… A year of ‘natural pretreatment’ and they may yet germinate alongside the Set D seeds!) This time I am boosting my chances of success by trying out three different methods of pretreatment advised by the Forestry Commission in their Practice Guide Growing trees and shrubs from seed by Peter Gosling (2007) [available online in .pdf format here].

Rowan seeds are classed as orthodox, deeply dormant seeds – ‘orthodox’ meaning easily stored and ‘deeply dormant’ meaning they ‘remain outwardly inactive under all conditions’, i.e. they require pretreatment to bring about germination. In the wild, rowan seeds would remain dormant for a year or two before germinating – the ‘natural pretreatment’ I mentioned above.

You’ll remember that I collected seed from two different individual rowans: a tree on Whitwell Moor and a tree above Oaken Clough. I kept each seed collection separate to find out if there is any difference in growth or form between the seedlings of the two trees. I also divided each collection into thirds so that the seeds of both trees will undergo all three of the pretreatment methods recommended by Growing trees and shrubs from seed. I’ve provided an abridged version of each of those methods below:

A. “Easy: natural (outdoor) pretreatment / sowing with medium”

1. Prepare a moisture retaining medium by mixing one part organic material (such as peat or decomposed leaf litter) with one part coarse particle material (such as sand or grit).

2. Mix one part seeds with one part moist medium and place in a container which is open to rainwater at the top and has drainage holes at the base.

3. Pretreatment: place container outdoors for thirty (16 – 30) weeks, positioned so as to receive exposure to seasonal temperature changes whilst avoiding daily temperature fluctuations.

4. Inspect seeds regularly (weekly to fortnightly) and if necessary re-moisten the stratification mix or remove decaying seeds to prevent the spread of fungal infections.

5. Remove and sow germinating seeds (or sow all seeds when 10% have begun to germinate).

A. On Saturday I filled two small plant pots with a one part compost, one part sand mix. Into one pot I mixed a third of the Whitwell Moor seeds; into the other I mixed a third of the Oaken Clough seeds. I’ve placed the two pots outside where they are open to rainwater but should avoid large fluctuations in daily temperature. There they shall remain until spring. Sixteen to thirty weeks from the 10th of October gives us a planting window open from the 30th of January to the 8th of May. I’ll probably plant all of the Set D rowan seeds proper in March.

B. “Moderate: artificial (temperature controlled) pretreatment with medium”

1. Prepare a moisture retaining medium by mixing one part organic material (such as peat or decomposed leaf litter) with one part coarse particle material (such as sand or grit).

2. Mix one part seeds with one part moist medium and place in a container, leaving a gap in the top.

3. Pretreatment: two (2 - 4) weeks warm followed by thirty (16 - 30) weeks cold. Use the main compartment of a refrigerator for the cold phase.

4. Inspect seeds regularly (weekly to fortnightly) and if necessary re-moisten the stratification mix or remove decaying seeds to prevent the spread of fungal infections.

5. Remove and sow germinating seeds (or sow all seeds when 10% have begun to germinate).

B. On Saturday I filled two empty yoghurt pots with a one part compost, one part sand mix. Into one pot I mixed a third of the Whitwell Moor seeds; into the other I mixed a third of the Oaken Clough seeds. I’ve placed the two open-topped pots in the fridge where I’ll ensure that they remain moist until spring.

C. “Skilled: artificial (temperature controlled) pretreatment without medium”

1. Place seeds in a loosely-tied woven bag and rinse / soak in cold (+4°C) water for forty-eight hours to remove any chemical inhibitors.

2. Drain seeds in a sieve to obtain imbibed, surface dry seeds.

3. Transfer seeds to a polythene bag. Leaving an air gap above the seeds, loosely tie the neck of the bag with a finger-sized hole to permit gaseous exchange but retard drying.

4. Pretreatment: two (2 - 4) weeks warm followed by thirty (16 - 30) weeks cold. Use the main compartment of a refrigerator for the cold phase.

5. Inspect seeds regularly (weekly to fortnightly) and if necessary re-moisten the stratification mix or remove decaying seeds to prevent the spread of fungal infections.

6. Remove and sow germinating seeds (or sow all seeds when 10% have begun to germinate).

C. On Saturday the 3rd of October I started separate 48-hour soakings of the Whitwell Moor and Oaken Clough seeds. I rinsed the seeds two or three times during the 48-hours. A week later (last Saturday), I transferred the surface-dry seeds to two small polythene bags and placed them in the fridge.

So there you go. Will the seeds make it through the winter? Will any of them germinate next spring? Will there be any difference between the Whitwell Moor and Oaken Clough seedlings? Which method of pretreatment will be the most successful? Only time will tell!!!

A walk through Yew Trees Lane Wood (Part One)

This set of photos isn’t very recent. I took them three weeks ago, on the 26th of September – the day I collected cut-leaved beech nuts for treeblog Set D. It was a beautiful, beautiful day.

Entering Yew Trees Lane Wood from the fields, you are plunged into an amazing environment of dense foliage and huge pine trunks.

It may not look very big in this photo, but the tree in the centre is a very tall, very straight beech (Fagus sylvatica). It’s a cracking specimen!

A walk through Yew Trees Lane Wood (Part Two)

Holly (Ilex aquifolium). Psst. Wanna see a photo of the same holly in February?

Three brothers. On the left: a hawthorn (Crataegus monogyna). In the middle: a fairly recently deceased beech (Fagus sylvatica). On the right: a longer-dead tree, probably a beech also.

Mushrooms and beech leaves

Any idea what species these are? I’m useless at identifying fungi. I need to get myself a decent field guide and get self-improving! I think these might all belong to the Russula genus, but I’m not confident. These mushrooms were: seen in South Yorkshire, England; at the end of October; in an area of woodland composed predominantly of European beech (Fagus sylvatica) with a handful of English oak (Quercus robur).

October 2009

treeblog Set D: collection and pre-pretreatment of rowan seeds

Two species of caterpillar on the grey alders

Of Arcite’s funeral (A Knight’s Tale)

Set D: sweet chestnuts collected & planted

treeblog Set D: pretreatment of the rowan seed

A walk through Yew Trees Lane Wood (Part One)

A walk through Yew Trees Lane Wood (Part Two)

Mushrooms and beech leaves

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