December 2013

December 2013

A look at goings on in December 2013.

Update of 16th December

It has turned wet here and it feels like winter is kicking in. I continue gardening in drier moments with compost and manure to spread, trees to prune, hotbeds to dismantle and experiments to maintain.

I have many salad leaves to pick. When growing winter salad commercially, apart form a lull in January, the darker months can be a busy harvest-season. For example Christmas salad is popular, and thanks to the mild December so far, leaves are bountiful undercover, with even some nice ones outdoors.

Day length affecting growth

In fact I have been interested to observe all the new growth there has been in the short days of December, when usually it is reckoned that low light levels prevent much growth happening. We have sunrise at 8.07am and sunset at 4.04pm, so day length is well below the ten hours (as quoted by Eliot Coleman, between sunrise and sunset) as necessary for meaningful growth. Coleman calls it the ‘Persephone effect’, because she lives, in winter only, with Hades who abducted her. During this period her mother Demeter, the Earth goddess, shuts down plant growth as a result of her sadness at losing her daughter over winter.

At latitude 51, in southern Britain, the threshold of ten hours sunlight is crossed on October 27th and back again on February 16th. So I am grateful that during this long period, Demeter allows growth! Recently I have been picking amazingly large and healthy new leaves of mustards, lettuce, spinach, winter purslane, leaf radish, endive et al. The lettuce in particular has been way larger and thicker than usual, a combination I guess of mild temperatures (first 15 days of December, av. low of 3.4, av. high of 9.6) and well fed soil, with good compost on the surface: also not over-watered, once every three weeks or so at the moment, a decent soak and then allowing the surface to dry out between waterings. This reduces weed growth and ensures that the mostly dry leaves suffer less mildew.

Lettuce in particular needs care in watering as it is so susceptible to mildew in winter. Growing the variety Grenoble Red helps as I find it amazingly resistant to fungal attack, and also it suffers less slug damage, than cos types especially. For example I have some nice Winter Gem cos lettuce but they are often nibbled around the edges or at the base of their stems.

Outdoors in milder areas, there is still time to sow or plant broad beans, even garlic if you still have some to go in. I am about to harvest the last celeriac which have continued to swell until recently, but now their leaves are mostly diseased and they may store better indoors than in the soil, when trimmed carefully to leave some soil around their roots.

There are conflicting weather forecasts for the winter. Headline grabbers are the stories of deep cold but most I have seen are for average weather, and the only thing we know is that nobody knows! Who forecast the hot July?

Here, November turned out quite average in temperature with below average rainfall and above average sunshine (though it still felt dark!). Do you remember that incredibly warm November of 2011?

2010 2011 2012 2013
Av. day C 8.7 13.3 9.7 9.4
Av. night C 2.3 7.1 3.1 3.4
Rainfall mm 100 96.1 142.4 65.8
Sunshine hrs 75 73 55 86
Frosts 10 1 5 7

In 2013 it was very mild at first and outdoor salad was amazingly productive until some frosts: we had -5C on 26th and that made a difference, even rotting some bulb fennel in the polytunnel.

Outdoor lambs lettuce is more slug-eaten than usual and the damp autumn has seen quite an explosion of slugs after the dry summer: I think their many eggs were just waiting for the first moisture. A neighbouring grower of long experience made the same comment and said it took him by surprise, with slugs even in cabbage hearts. Best remedy for that is to harvest before too many get in there, but the mild weather has meant that early harvests for winter storage are not keeping so well. I waited as long as possible and harvested dense heads of Filderkraut and Huzaro cabbage on November 17th, now they are in crates in the barn. Some outer leaves decay slowly and need peeling off before eating the good inner leaves, which should keep until March if winter is not too mild.

Now is the season of spreading compost and I have been frustrated by having a bad back, from log splitting. Still I managed to empty the greenhouse hotbed, for refilling in early February. The manure had rotted nicely but with many wood shavings still intact, so I spread it in pathways to create a less sticky and easier to weed surface than the clay soil. The cardboard has done its job since February and all perennial weeds are dead, except for field bindweed.

A couple of pathways had grass re-growing so I put some thin cardboard on that before spreading an inch or two of the woody manure.

Also I have been removing the wooden fence posts and rails which were holding the shape of my beds, to stop their compost falling on carded pathways. Their job is now done and when removing them, I was cutting a fair number of slugs and composting their eggs. The photos below show how beds that were 12-15cm high (5-6in) with manure and compost last December, are now one third of that in depth, and ready for another inch or two of manure or compost on top. I have about three tons of my own to spread and a big pile of manure.

More on Experiments

On left is a dug bed, on right is undug, neither had any compost, see results of harvests in table below.
On left is a dug bed, on right is undug, neither had any compost, see results of harvests in table below.

A new experiment for next year is comparing growth with and without rockdust. I have spread an inch on one side of the beds where I have also been comparing growth using no compost, between digging and not digging. Then a third undug bed with compost on top. So we have:
Bed 1, dug with no compost
Bed 2, undug with no compost
Bed 3, undug with two inches (5cm) compost on top.
See previous posts for reports of this, also called the Shumei experiment.

The only remaining harvest is Bandit leeks, 12 clumps on each bed for picking in early spring.

Shumei and compost trial first year – Three beds 2m wide, 9m long

Vegetable 1 Dug bed 


2 Undug bed 


3 Undug, compost kg
Beans Czar 0.95 0.83 0.75
Beans Borlotti 0.57 0.23 0.77
Squash Kabocha 4.39 (3) 2.74 (2) 7.75 (3)
Squash Kuri 5.42 (7) 3.07 (4) 8.95 (9)
Celeriac 1.51 1.14 2.82
Beetroot 16.56 20.86 25.96
Leek Zermatt 1.60 1.37 2.48
Leek Bandit still to harvest M-A in March-April in March-April
Cabbage Filderkraut 5.50 6.18 6.16
Cabbage Kalibos 1.51 0.85 1.14
TOTAL kg 38.05 37.27 56.78

Harvests, Storage

I hope you have lots of produce put by. These photos comparing a dried onion and one just harvested, of the same sowing, show the benefits of good harvesting: