Storm Gerrit

The wind speed record for 2023 - as recorded in our back garden by my Davis Weather Station - was recently set at 56 km/h during Storm Pia (December 20th - 21st). A few days later that record was smashed by Storm Gerrit (December 28th) with a wind gust measured at 61 km/h!!! (Figure 1).

Figure 1: Daily Mean & Highest Wind Speeds (December 2023) in Hereford

Storm Gerrit (G) was more intensely felt in Hereford because it came with significant rainfall whereas Storm Pia (P) was accompanied by dry weather (Figure 2).

Figure 2: Daily Rainfall (December 2023) in Hereford

Conditions were much worse in other parts of the country ...

Video 1: Sky News Report on Storm Gerrit

Video 2: Planes in Trouble (The Telegraph)

Storm Pia affected more countries and there were twice as many fatalities. Here is a really nice video from The Whitby Photographer. If you watch the video, perhaps you can explain why members of the general public put themselves, and their kids, at risk just to take a photo they'll probably never look at again.

Video 3: Storm Pia at Whitby, Yorkshire

Hot Composting - The Importance of Aeration

While tending my HotBin compos bin over the Christmas holidays, I was reminded of the importance of compost aeration. I'll come to that in a moment but, first, I thought I should give a quick recap of the 'ingredients' needed for the successful hot composting of garden waste:

1. A population of micro-organisms (fungal and bacterial) to breakdown the plant waste into a stable organic soil conditioner (finished compost) - garden waste will contain most, if not all, the necessary micro-organisms albeit at levels too low for rapid hot composting; hence the need for ingredients 2, 3, 4 and 5! Inoculating a new compost heap/pile/bin by recycling a sample from the previous compost heap/pile/bin will get you off to a fast start. I inoculate new and existing HotBin compost bins with course material sieved from my finished compost.
2. A carbon-based energy source - the bulk of the plant waste provides this component, for example, in the form of polymeric (e.g. lignin) and complex (cellulose, hemicellulose) carbohydrates. Microorganisms oxidise carbohydrates to carbon dioxide (CO2), water (H2O) and energy for cell growth. Some of the energy is also released as heat and raises the temperature of the compost pile. Both brown and green garden waste are a 'food' source for the essential micro-organisms in your compost heap.
3. A source of nutrients - predominantly nitrogen but also phosphorus, potassium and trace elements (sulfur, magnesium, manganese, calcium, cobalt, zinc, copper, molybdenum, etc). Nitrogen is the most significant nutrient being a major element in the biosynthesis of the amino acids and proteins needed to increase the activity and population of micro-organisms (see 1 above). Green waste is the main source of nitrogen. The general rule is to have a carbon/nitrogen ratio (C:N) somewhere between 20:1 and 40:1. Above 40:1, the lack of nitrogen limits bacterial and fungal growth. Below 20:1, too much nitrogen can lead to anaerobic conditions producing ammonia and putrid odours. The home composter learns by experience what a good green/brown balance is for their compost bin. You should err towards 20:1 when starting a new compost pile. In my experience, a well-functioning HotBin (say running at 60 ℃) can cope with a greater variety of C:N ratios.
4. A regular supply of oxygen (aeration) - this is used by bacteria and fungi to oxidise the carbon-based energy source (see 2 above) and provide energy for bacterial and fungal growth; a byproduct of this oxidation is heat that raises the temperature of the compost pile and speeds up the composting process (positive feedback). Traditionally, the supply of oxygen is controlled by regular turning of the compost heap. The HotBin composter is engineered to enable this aeration process to occur automatically without any physical intervention.
5. Moisture -  water is added to the compost pile as a constituent of the garden waste and is also produced as a part of the composting process (see 2 above). A moisture content of 40-65 per cent is considered ideal for composting. Too little water slows the composting process and too much can lead to anaerobic conditions (slow and smelly compost heaps). A simple 'squeeze test' such as this or this will make sure you are in the right ball park. In my experience, if the top active layer (10 cm) of your HotBin is running at 60+ ℃, then you don't need to worry about moisture content. Free water will naturally gravitate to the bottom of your HotBin. Generally, this is fine because composting worms prefer a higher moisture content (80-90%); however, it can be a problem if the compost becomes too compact and reduces the oxygen supply (see 4 above) to the upper active (i.e. hotter) layers.

OK! Back to the two incidents that reminded me of the importance of aeration.

Thanks to my neighbour's hedge cutting, there has been plenty of green and brown garden waste for hot composting this winter. December has been very mild after the cold snap at the beginning of the month. Approximately every 10 days, I will remove around 80 litres of partially-composted waste from the hatch of my 200 litre HotBin (Photo 1) and transfer it to one of my maturation bins where it will spend at least another 6 months before being used in the garden either before or after sieving.

Photo 1: Removing Part-Composted Waste from the HotBin Hatch

A few days ago, I noticed the top vent on the HotBin was fully closed (Photo 2) and the lid thermometer temperature had dropped to 37 ℃ from the 54 ℃ it had been on the previous day. The temperature of the top 10 cm of compost had also dropped from 61 ℃ to 50 ℃.

Photo 2: Closed Air Vent on HotBin

Whether the vent had closed by accident or, as in the past, because one of the local cats had chosen the top of the HotBin as a pleasantly warm place to rest, we will never know for sure. In any case, I needed to reinvigorate the bin and get it back up to hot composting temperatures.

First, I transferred 80 litres of partially composted material from the hatch of the HotBin (Photo 1) to one of my maturation bins where the composting process would continue under the supervision of local worm population. After refitting the hatch and resettling the contents, I added two hot water bottles and 24 litres of fresh garden waste before covering with a reflective mat and resetting the vent valve to its correct position (about a 2 - 3 mm gap). The lid thermometer now read 32 ℃ (Photo 2) but within a couple of hours it was reading 35 ℃ (Photo 3); a good indication the bin was back on the way to full health.

Photo 3: Correctly Positioned Lid Vent 

Unfortunately, the next day, while checking the HotBin during Storm Pia, I found the vent fully open (Photo 4). I'm assuming blown open by a gust of wind catching the edge of the adjustable valve.

Photo 4: Fully open HotBin vent valve

The lid thermometer read 37 ℃ and the upper compost layer was 53 ℃. It needed another two days of hot water bottles and fresh waste before the upper compost layer reached 60 ℃ and the lid thermometer read 50 ℃.

Figure 1 shows the HotBin compost temperatures at 30 cm and 10 cm before, during and after the problems with the aeration valve. The period when the valve was shut is shown in green and when it was fully open in yellow.

Figure 1: Compost Temperatures Before and After Aeration Issues

Shutting the valve reduced the natural aeration of the compost bin and had the largest effect with a > 10 ℃ drop in compost temperature over a 24 hour period. The fully open valve resulted in a slower heat-up rate due to the greater heat loss through the valve. Once the valve returned to its normal position (Day 6), the top 30 cm of compost quickly heated up to 55+ ℃ and, within a few days, was running at over 60 ℃. Combined with the use of a heat reflecting blanket, the compost was maintaining a temperature of 50 ℃ even at a depth of 50 cm.

To prevent possible accidental closure by neighbourhood cats or unexpected openings by wayward winds, some additional protection was offered for the aeration valve ...

Photo 5: Cat Deterrent and Wind Protector

When Doing the Bare Minimum Never Seems Quite Enough

 Welsh Water (Dwr Cymru) has been doing some essential public works in the surrounding streets that included digging up roads and pavements. They worked diligently and reinstated the roads to something like their original condition. This involved using a minimum amount of yellow paint (Photo 1) ...

Photo 1: Road Markings after Reinstatement

On the narrow streets around here, where there are too many cars for the available car parking spaces, the new yellow lines may be a little confusing. You can just make out that the yellow lines stop this side of the gate. It would have helped if the contractors for Welsh Water had removed the overlay of dirt on the existing yellow lines that were not there before they started their excavations.

Photo 2: New & Old Road Markings

Better still, the local authority could have asked them to repaint the existing lines to clearly demarcate the parking and no parking zones. Betterer still, the local authority could have reassessed the lengths and locations of the "no parking double yellow lines" and squeezed a few more parking spaces in these streets. When I asked the local authority to review the situation a few years ago, I got the impression it would be a lot of trouble and cost a fair bit of money.

Unfortunately, we have a few thoughtless residents who think nothing about parking opposite the street exit (Photo 2). It may be a peculiarly English trait that people believe they have the right to park immediately outside their front door - and that nobody else should infringe on this basic human right. Today, I have seen two vans (Ford Transit-type) negotiate this corner with difficulty, having had to mount the pavement to get round. Larger vehicles (fire engines, ambulances, refuse collectors) find it impossible to take this corner when someone is parked there and have to reverse back down the street.

Doing the bare minimum or quiet quitting seems to be more prevalent these days.

Storm Pia

Storm Pia, named by the Danish Met Office, hit the UK on December 20th - 21st. Fortunately, Herefordshire was on the edge of the warning zone and escaped the most damaging winds.

Video 1: Storm Pia viewed from the Rear Garden

Video 2: Robin in a Spin (Storm Pia)

Video 3: Scudding Clouds (Storm Pia)

Checking the 2023 wind records, monitored by my Davis Weather Station, December 21st turned out to be the windiest day of the year so far (Figure 1). A top speed of 56 km/h at 11.30 am (21/12/23).

Figure 1: Highest and Average Wind Speeds (Daily) in 2023

The UK Storm Season runs from early September to late August in the following year. Figure 2 covers this year's storm season (double click for larger image).

Figure 2: 2023/24 UK Storm Season (Highest & Mean Daily Wind Speeds in Hereford) 

Some of the named storms are indicated in Figure 2: Debi (red dot), Elin (green), Fergus (blue) and Pia (black).

It has been a quiet year for storms in Hereford - something to be thankful for.

Cat Deterrent

 

Photo 1: Neighbour's Cat has Spotted Something in the Tree 

We are surrounded by cats and, presumably, cat owners. We are not keen on felines though we would not wish them any harm. They are useful as mousers (I've disposed of two dead rats found in the kitchen garden) but they are always leaving their calling card on any bare patch of soil and can decimate the local bird population.

Well, you might say, then don't leave any bare soil patches! But that is easier said than done in a working kitchen and flower garden. We've tried all sorts of deterrents including ultrasonic repellers (fine for an open lawn but the signal easily blocked by growing plants, etc), fence/wall spikes (the cats just walked along them as if they were a deep-piled carpet), water pistol (doesn't work if you're not there), chicken wire (they always seem to find the small gap)and various smell-based deterrents (orange peel, citrus and essential oil sprays, etc) which seem to last only as long as the next cat visit.

The best cat deterrent, in my opinion, is a magpie on parental duties. These aggressive birds, especially when they have young to protect, have no qualms attacking a cat that gets even remotely close to the nesting site.

Recently, I've been emptying my compost bins and mulching the autumn raspberries. As a final top dressing, I add a one to two inch (2.5 -5 cm) thick layer of bark which is a good cat deterrent if not a 100% guaranteed one.

Photo 2: Autumn Raspberry Plot after Mulching with Compost & Bark

The rhubarb patch received a different treatment. After mulching with compost and recovered coir (from finished Quadgrows), I placed some upturned tomato grow pots over the plot to deter the cats (Photo 3). I haven't tried this before so I'm hoping it will work.

Photo 3: Upturned Tomato Grow Pots as Cat Deterrent

Apart from having to clear up their mess, this is the main reason for deterring cats in our garden:

Video 1: Blue Tits on Feeder

Hot Composting - A Cover Up?

 

Photo 1: HotBin next to Conventional Garden Composter

There are three main reasons why you should hot compost your garden and kitchen waste using, for example, a HotBin:

1. to speed up the multi-year composting process
2. to kill off weeds and pathogens
3. to allow cooked food, including meat, to be composted without attracting vermin

Although the availability of garden waste decreases in the winter months, you may want to keep composting through the colder weather with kitchen scraps, etc. Hot composting over the winter presents its own challenges such as having sufficient quantities of waste and maintaining compost temperatures (50 ℃ to 60 ℃) in sub-zero conditions.

A well-insulated bin is top priority (Photo 1). A little ventilation is necessary because air (i.e. oxygen) is necessary for the aerobic decomposition of vegetative waste. Too much ventilation, especially in sub-zero winter temperatures, might cool the composting material too much. You will not be surprised to hear that the HotBin has all these requirements covered.

In my experience, the HotBin and Super Compost Bin often benefit from a cover laid over the compost surface, especially when: (i) the bins are only partially full, and (ii) during cold weather.

Photo 2: Fleece Cover in Super Compost Bin

If the bin is only part-filled then the cover helps retain heat within the compost pile rather than heating the air space above (before escaping via the lid vent). When the bin is at full working temperature (60 ℃ to 70 ℃), it has a tendency to dry out quickly and the mat helps retain some of the moisture. [Note: remove the mat if the compost is too wet and let it dry out before replacing it].

Up until recently, I have always used a fleece-type material, typically capillary matting - the thicker the better - cut to fit loosely over the top of the compost (Photo 2). As the weather started to get colder (late November), I thought I'd try a more reflective non-adsorbent material that would reflect heat (infra red) back into the compost pile but allow moisture to escape.

Photo 3: Reflective Indoor Grow Sheeting

The material is easy to cut with scissors and position on top of the compost ...

Photo 4: New Reflective Sheet in HotBin

The following day everything seemed to be working fine; some of the hot water vapour had condensed out on top of the sheeting; this can be discarded if the compost was wet enough or added back if it was too dry.

Photo 5: Reflective Sheet in Action

Figure 1 plots compost temperatures at 50, 30 and 10 centimetre depths; for comparison, the minimum overnight temperatures in the garden are also plotted. The cold frosty period at the end of November/beginning of December (Day 3 to Day 12, Figure 1) coincides with lower compost temperatures. The temperature of the upper active layer (top 10 cm) maintained its temperature reasonably well - it did, however, receive extra help in the form of two daily hot water bottles on days 8, 9, 10 & 11 (overnight subzero temperatures). Fresh compostable material was added every day. The arrival on Day 10 of a neighbour's green hedge trimmings (Photo 6) greatly helped.

Figure 1: Daily Compost Temperatures at 50, 30 & 10 cm & Minimum Daily Temperature

Photo 6: Fresh Supplies of Garden Waste

It is too early to say whether the reflective mat is working as I hoped but initial results are encouraging. Compost temperatures drop noticeably when the outside temperature drops below 0 ℃. This effect is smaller in the upper layer provided sufficient fresh easily composted material (e.g. kitchen waste) is added regularly. The addition of hot water bottles helps especially when the outdoor temperatures fall well below zero (Days 10 & 11, Figure 1).

Since a plentiful supply of green compostable material arrived (Day 10, Figure 1) in the form of a neighbour's hedge trimmings, there has been a significant improvement in the overall performance of the HotBin. The temperatures at 30 cm and 50 cm depths have, in particular, been boosted. Whether this is due to the mat reflecting heat, generated in the active top layer, back into the heap is difficult to say. But I'd like to think it is a factor. The dip in temperature on Day 21 (Figure 1) came about because I removed 80 litres of already composted material from the HotBin hatch; the measured temperature at 50 cm depth was very close to the baseplate of the HotBin.

The conditions on Day 23 (Figure 1) are close to ideal with the top 50 cm of the compost pile operating at 50 ℃ or above. A slightly hotter upper layer (top 10 cm), say 60 ℃, would be nice but one mustn't be greedy.

The new reflective mat is easier to use than the old fleece mat which would absorb water and need to be wrung out everyday. The experiment continues ... 

A Winter Stew from the Kitchen Garden

 Saturday 9th December 2023 was a funny old day weather-wise (Figure 1). Up to and including the 11th December, it was the warmest day of the month reaching a high of 13 ℃ between 10.30 am and 12 noon. There was also plenty of sunshine (green) especially between 10.30 am and 2.30 pm and plenty of light showers (blue) throughout the day.

Figure 1: December 9th 2023 Weather

It was the sort of day where rainbows should be visible though this example was from the day before.

Photo 1: Rainbow over Hereford

It meant a lot of toing and froing between the house and kitchen garden as I went looking for vegetables to add to the winter stew I was preparing. The first port of call was the root vegetable plot - the basis of any good winter stew. Here I dug up, knobbly carrots, hairy celeriac, elongated parsnips and rotund beetroot. 

Photo 2: Carrots, Celeriac, Parsnip and Beetroot

The second port of call was the brassica patch where I picked the last two cauliflowers of the season, including a Romanesco with its fractals and Fibonacci sequence, and a red cabbage (Photo 3).

Photo 3: Red Cabbage and Cauliflowers

The colour of red cabbages is affected by the pH of the soil: redder leaves in acidic soil, purple in neutral and greenish-yellow leaves in alkaline conditions. I think my soil is neutral with a slight tendency to acidic. One day I will find out when I analyse my soil with my new soil test kit.

A warming winter stew is very easy to make in a slow cooker and most of the ingredients can be grown in the kitchen garden. In addition to the freshly-picked carrots, parsnips, beetroot, celeriac, and cauliflower, I added homegrown onions, potatoes, green beans (from the freezer), celery, garlic and jalapenos. Some vegetable bouillon and herbs (fresh or dried) and leave on a gentle boil for 4-5 hours.

Photo 4: Winter Stew

Eat with freshly-baked bread and a side portion of easy coleslaw (red cabbage, carrots and Golden Delicious apples with vegan mayo).

Photo 5: Golden Delicious Apples from the Garden

Frosty Days are Here Again

 

Figure 1: Minimum Daily Temperatures (November 8th - December 7th 2023)

In our Hereford garden, the first air frost (temperature < 0 ℃) of this winter arrived at thirty minutes past midnight on the morning of the 25th November. Figure 1 displays the minimum daily temperatures between the 8th November and the 7th December 2023. The first air frost appeared at the start of a chilly 10 days at the end of November and stretching into December. Those first few air frosts were enough to cut short the dahlia (Photo 1) and fuchsia (Photo 2) blooms.

Photo 1: Frosted Dahlia (27/11/23)

Photo 2: Frosted Fuchsia (27/11/23)

Although the Salvias did not appear to notice ...

Photo 3: Frost Hardy Salvia (27/11/23)

In the kitchen garden, fleece provided some protection for celeriac even though they are frost resistant ...

Photo 4: Celeriac Frost Protection

A harder frost was just around the corner with temperatures dropping to -5 ℃ on the 1st December and even lower (-7 ℃) on the 2nd. The bird bath froze over (Photos 5 & 6) with some interesting ice patterns.

Photo 5: Frozen Bird Bath (7/12/23)

Photo 6: Ice Patterns in the Bird Bath

The Swiss Chard plants suffered in the -7 ℃ frost but recovered a day or two later.

Photo 7: Swiss Chard after -7 ℃ Frost (2/12/23)

The garden took on a magical wintry look and we had lots of visitors to the bird feeders.

Photo 8: Frosted Garden

Cobwebs you never knew were there suddenly appear ...

Photo 9: Frosted Weather Station

... creating incredible structures in the air ...

Photo 10: Cobweb Canopy

Many of the plants were covered in ice crystals like these rose hips (rosehips, rose haw, rose hep) ...

Photo 11: Ice Crystals on Rose Hips

After the cold snap, temperatures have picked again as shown in Figure 2. For the last seven days (5th to 11th December inclusive), mean daily temperatures have averaged +7.5 ℃ which is 3 ℃ above the CET average for December. Not quite t-shirt weather but I've managed to do a lot of tidying up in the garden.

Figure 2: Mean, Max and Min Daily Temperatures (12/11/23 to 11/12/23)

A Hot Composting Saga (Part 6) - Draughtproofing

 I was doing a bit of admin and realised I hadn't completed this series of posts. See here for Part 5 and links to the earlier articles. This is the final one on this particular topic though there will be plenty of future posts on hot composting.

To bring you quickly up-to-date, I have three hot composting bins: one is an early version of the HotBin (possibly Mark 1 or maybe earlier) along with two prototype hot composters (Super Compost Bins) supplied by Tony Callaghan, inventor of the HotBin. In spite of its age, my HotBin is still working well, enabling me to successfully hot compost through the winter months due to the excellent insulation provided by the one-piece expanded polypropylene body (no leaky joints!).

By way of contrast, the prototype Super Compost bins require self-assembly meaning there are plenty of potential cold spots at the joints.

Photo 1: Unpacking the Prototype Super Compost Bin

After several years of untroubled hot composting with the Super Compost bins, this Spring I was having all sorts of problems getting the bins up to working temperatures (50 ℃ - 65 ℃). Figure 1 plots the daily compost temperatures (measured at depths of 10 cm and 30 cm) of Super Compost Bin #2 along with the cumulative volume of added garden waste. This was a successful hot composting process with temperatures in the active (top 10 cm) section of the heap remaining above 60 ℃ for 40 days and 40 nights; there were a couple of periods, around day 22 and day 35, when the temperature dropped below 60 ℃ because the bins were left unattended due to holidays.

Figure 1: Daily Compost Temperatures (℃) and Cumulative Garden Waste Added for Super Compost Bin #2 (10th October 2022 to 20th November 2022)

Table 1 presents the equivalent data for the subsequent hot composting run in the same Super Compost bin. Despite daily attempts to boost the temperatures using hot water bottles, the active zone only achieved temperatures in the mid-forties (℃).

Table 1: First Hot Composting Attempt in 2023 with Super Compost Bin #2

DAY	Added Garden Waste (Litres)	T oC @ 30 cm	T oC @ 10 cm	Minimum Daily Temperature (oC)
1	94*	not measured	not measured	6
2	18*	19	35	7
3	20*	23	37	3
4	10*	26	34	4
5	8*	27	44	1
6	8*	32	40	6
7	0	36	43	4

* Two hot water bottles added daily to kickstart the hot composting process

Having fixed the first Super Compost Bin with some self-adhesive draught excluder, it was time to turn my attention to Super Compost Bin #2. As there was insufficient draught excluder for the second bin, I decided to utilise some thick capillary matting previously used as a tray liner for controlled watering of potted plants.

The Super compost Bin was dismantled and cleaned before reassembling using strips of capillary matting to fill the joints in the four side pieces (Photo 2) ...

Photo 2: Capillary Matting used as Draught Excluder in Super Compost Bin Joints

The lid of the Super Compost Bin rests on rubber tubing seals that were not sealing properly. Some old packaging material (recycled jeans!) was used to fill any gaps and reduce the escape of hot air (Photo 3) ...

Photo 3: Operating Super Compost Bin with Extra Lid Seals

A similar system was used on the first Super Compost Bin. Photo 3 was taken when the Super Compost Bin was in operation (details below); note that the hot compost is covered with a sheet of capillary matting to help retain heat and stop the compost drying out too quickly.

After the refit, the Super Compost Bin #2 once again worked to specification (Figure 2) with temperatures in the active region (upper 10 cm) ranging from 57 ℃ to 70 ℃ for the first 28 days.

Figure 2: Daily Compost Temperatures (℃) and Cumulative Garden Waste Added for Super Compost Bin #2 (8th July 2023 to 8th August 2023)

A better test of the 'leak-proofing' would be a hot composting run when the weather is colder. Figure 3 summarises such a run that started on the 7th November 2023. The green line represents the daily minimum outdoor temperatures that dropped below 0 ℃ towards the end of November. The yellow line, representing the upper (top 10 cm) active layer of the compost heap, maintains a mid-50 ℃ to mid-60 ℃ temperature range for the first 25 days until the bin is full.

Figure 3: Daily Compost Temperatures (℃), Outside Minimum Temperature and Cumulative Garden Waste Added for Super Compost Bin #2 (7th November 2023 to 3rd December 2023)

The three hot composting runs shown in Figures 1, 2, & 3, consumed around 400 litres of shredded garden and kitchen waste - equivalent to between 600 and 800 litres of pre-shredded waste. I will leave the full compost bin until spring to continue maturing before transferring the contents to my maturation bins for finishing off.