Summer comes to the poly tunnel early
(Dave, Simon, Richard and Tony) set out to erect a large poly-tunnel on
the allotments in the summer of 2013 we had no idea what lay ahead.
Tony had the bright idea following a disappointing growing season the
previous year and David and Simon had spotted a derelict poly-tunnel
frame on one of their family caravan weekends, so the project came into
being when the four of us committed in the summer to make the project
happen; we never decided who was Foggy!
result from our point of view was a 60ft protected growing area which
was complete in late Autumn. We had collectively cleared the
site, burnt off the stubble, then rotavated and then hand dug it once
again after the tunnel was up.This clearly left us with an excellent
wed free growing medium which was looking in need of planting; this we
viewed from the seated social area within the poly-tunnel where we were
having coffee and biscuits.
So what to plant? We didn't know what would germinate or even if plants
would over winter. Selfset bean plants were brought into the tunnel,
they rocketed over Christmas and then failed from Botrytis- we had not
ventilated enough, (this led to a modified vent system on the
doors!). Other crops were planted by each of the group and we
waited for spring to happen but oh boy dis it happen fast?
The instant heat produced by any sun and the increasing daylight hours
have speeded up the growing pace so in late April we have achieved a
poly-tunnel summer! Believe it or not we have just harvested
potatoes, peas, beetroot, carrots and the first strawberries of the
year have been eaten.
We are learning fast and look forward to completing our first year in
the poly-tunnel so we can review which crops enjoyed the tunnel
environment, ready for another exciting and interesting year growing
The two large covered growing areas have come up with different ways of
collecting and storing water. The poly-tunnel boys have devised
their own stick-on guttering system leading to barrels sunk in the
ground. which is then pumped to barrels at ground level.
The communal greenhouse has conventional guttering so is collecting
rain water into 1000l tanks. A 1000 litres of mains water costs
over a £1 so great savings over the years are to be made.
The allium leaf miner
I have each year seen an increasing attack on my leeks of this nasty pest.
The miner tunnels down the leek causing
brown lines and eventually the whole leek collapse. The pupae seen here
will be obvious when you cut open your harvested leeks in the autumn.
Prevention is best achieved by covering all
alliums (leeks, onions, shallots and garlic) with insect proof netting
or fleece thus preventing the fly from laying its eggs on the
leaves. This is done in March/April and again in
September/October. With fast maturing alliums you can try
planting after the first period of attack.
Cabbage root fly Spring/summer 2012
the first time in my growing career I have been affected by cabbage
root fly. I first noticed an attack when the radish that I
planted with my parsnip had moth eaten leaves and never
developed. The turnips suffered the same fate and finally the
swedes which was planted some time later.
A later sowing of swede under some flease were also attacked but
developed to a greater extent. All the other brassicas appear
unaffected as yet but were planted as small plants and covered with
Environmesh also they had a thick layer of grass mulch.
Suggested prevention is to cover plantlets with fleece or fine mesh and
use fly-mats. If infected a nematode biological control called Nemasys
can be used. Paul
Onion White Rot August 2011
On harvesting my onions this year I found that in a small area close to the fence a number of my onions had white rot. This was not a big surprise as I know that a number of other allotments suffer from this condition.
white rot is the most serious widespread and destructive disease
affecting alliums (onions, garlick, leeks). It is a persistant,
soil-bourne fungus. Once in the soil it is extremely difficult to
control or eradicate.
Plants suddenly die. Roots stunted growth. White
cottony-looking fungal growth seen on the base and sides of the bulb.
Small, black, round fruiting bodies called 'sclerotia'are formed which
can remain in the soil for up to fifteen years. The presence of
an allium plant stimulates the fruiting body to germinate and infect
new plants. White rot is temperature dependent. It is only
active when the soil is between 10 and 20 degrees C.
Hygiene- avoid carrying infected soil on boots, tools etc.
Use a long rotation- 8yrs.
Sow seeds rather than sets.
Dispose of infected bulbs. Do not compost.
A trial based on incorporating onion waste inton the infected soil
appears to be effective. The sclerotia are stimulated into
germinating and die as no host plant is present. Waste from
brassicas has also been found to be effective.
(Horticultural Week Jan 2009)
A Cautionary Tale
I planted greenhouse
greenhouse tomatoes, raised in 1 litre pots and then into 50 litre
growbags as usual and was after three weeks or so disappointed to see
them looking distinctly unhealthy with poor growth and yellowing
foliage. Two were so sickly I replaced them. I had done
nothing differently to previous years and the other spares given to a
first year tyro were doing well (they went on to give an enormous crop
well into November). I then realised that my grobags were of a
non-peat variety though this was only in small print on the bottom of
the bags. In these days of ecological science this should have
made no difference but as a control I planted three small self setters
from the garden in a Tomorite peat grow bag. This was early July
and too late to expect too much of a crop from them. I persevered
with the originals but the results were effectively a crop failure -
pale and spindly, poor flowers-set, blossom-end rot and small
fruits. Some plants came better than others but non came anywhere
near expectations. The three self setters in the peat compost did
well in every way apart from being late though there is now a large
drawer of good sized fruits that will ripen until Christmas.
August I approached the supplying garden centre to enquire (not
complain) about my experience and was told they had sold pallet loads
of these grow bags with no other negative comments and "Was I
overfeeding?". E-mailing the manufacturer in a similar vein
produced a next day phone call from the production manager who
diagnosed a nutrition problem ; probably due to the basic
difficulty of mixing and milling the non-peat
ingredients and ensuring proper nutrient
distribution. He apologised, acknowledging that my
experience was not unique and offered generous recompense.
I shall be using peat based compost whilst it is available and hoping that green technology eventually comes good.
(Editor - Readers are very welcome to comment on Ken's article on the use of peat as a growing medium in the forum)