Procedure prior to planting
Greenhouse Clean and Trickle irrigation
clean and check.
1. Spray the crop with an appropriate broad spectrum
insecticide to eliminate any insect pests that may be
present in the old crop. This is for your own safety, as
crop removal disturbs the pests, which migrate to your
other crops or to your neighbors crops.
2. Turn off irrigation system and allow the plants to dry
out the root mat.
3. Remove old crop, and consign to the dump. Remove old
bags there has been disease problems, excessive salt
build up or if they are past their best. Most greenhouse
properties are too small to allow old crop remains to be
dumped on the property without risk of disease
persistence in the dump and future re-infection of your
own or neighbours crops. If the old plants do have to be
dumped on your own property then they should be either
burnt, or buried with soil or at least covered over with
4. Sweep up and remove all loose and plant debris and
5. Wash down all interior greenhouse surfaces and floors
with a high pressure water wash.
6. Fumigate or disinfect the greenhouse either by
spraying formalin or thermal fogging with formalin if
this is legally available for use in your location. Use
formalin at 1 litre of formalin in 50 litres spray or
about 1 litre formalin per 150m2 of greenhouse floor
area. For thermal fogging use 400ml formalin per 100m3
greenhouse space. Do not use stale formalin, it
polymerizes on keeping and is not effective. Good
protective clothing is required and a respirator
cannister rated for use with formalin. It is best to do
this during the afternoon while it is still warm and to
shut the greenhouse tight overnight. Ventilate the
following morning and do not work in the greenhouse until
the smell of the formalin has dissipated. It is also
possible to use a strong chlorine solution of 100ppm or a
commercial solution that contains the active ingredient
of Alkyl-dimethyl-benzyl-ammonium chloride. Rinse well
afterwards twice or three times. Protective clothing is
also required with both of these materials.
7. Wash overhead crop wires and any cradle wires using a
disinfectant. A squeegee mop on a long handle is most
effective for this, as the sponge can be clamped around
the wire while pushed down the length of the wire. Wash
and wipe any surfaces likely to be regularly handled by
dirty hands, e.g. door handles, ventilator winders etc.
8. Wire string hooks, cradle wires or any other plant
support parts which are to be re-used should be soaked in
disinfectant before being brought back into the house.
9. Thoroughly clean and check the trickle irrigation
system which helps to avoid many problems during the
growing season. The following notes assume that the
outside of the trickle system pipes has been cleaned
during the end of crop clean up. If not the pipes should
be water blasted or washed clean of any dirt or algae
before proceeding with the following steps.
10. Open the ends of the flow headers and flush out the
header pipes with clean water.
11. Disconnect the lateral pipes from the headers.
12. Open the far ends of the lateral pipes and connect
the header end to a hose pipe and flush out the lateral
with clean water.
13. Close the far ends of the lateral pipes and flush
clean water through the microtubes or drippers using as
much pressure from the hose pipe as possible. The
microtubes should all be squirting water very strongly.
Check for any missing microtubes. Check that each
microtube is flowing strongly and unblock or replace any
microtubes not delivering the full flow. Make sure that
any replacement microtubes are the correct length and
14. Re-connect lateral pipes to headers.
17. Each station of the irrigation system should have a
clear plastic sight tube to indicate the normal operating
head. Clean these clear plastic tubes by pulling through
a piece of rag on a wire or replace if the plastic is
discoloured and cannot be cleaned.
18. The water and feed supply to microtube trickle
systems should pass through a filter (preferable 200 mesh
or equivalent). Check and clean the filter.
Preparation for planting.
1. Preplant wetting
Wetting before planting is necessary to ensure that all
the bags have the same moisture content and that all the
media within the bags is uniformly wetted. Failure to
properly prewet bags may result in uneven plant
establishment and of funnelling of water straight through
the centre of the bags and out the bottom without any
lateral wetting of the media. Stand out planter bags in
final position and install microtubes or drippers. Hose
water bags with plain water until water runs out the
bottom of the bags. If modules are to be used place
modules in position but upside down (i.e. any prepunched
drainage holes on top). Insert microtubes into the bags
and apply water until bags are full of water. Then turn
bags the right way up, cut drainage slots if bags are not
prepunched, and allow to drain overnight.
2. Preplant feed
Apply about 1 litre of feed per bag (assuming bag of
about 8 - 10 litres is used) through the trickle
irrigation, using feed at CF 20-25.
Not all plants will be top quality so select good healthy
plants of uniform size for planting keeping plant size
uniform within rows.
Ex plastic pots : knock out plant
carefully, so as not to disturb roots, and plant with
cotyledons (seed leaves) just above the surface of the
sawdust or pumice.
Peat pots: plant with the rim of the
peat pot just buried in the sawdust or pumice but the
cotyledons must not be buried. Bottomless plastic pots :
stand pot with plant on the surface of the sawdust or
pumice or bury to a depth of 20-25 mm for better
4. Spare plants
It is worth setting up an extra half row with a trickle
line in a path for spare plants, planted into planter
bags as usual. These spare plants can then be used to
replace any plants that are not upto standard, or become
damaged or diseased prior to setting the fourth truss. At
that stage any unused spares need to be discarded.
5. Microtubes or drippers
Make sure that the microtubes or drippers are discharging
onto the root balls of the plants.
5. Post-plant Feed
Apply 150-200 ml of feed per plant immediately planting
6. Apply sand to sawdust
Much better water spread is obtained in sawdust bags is
the bag is topped with a 10-15 mm layer of fine sand. It
is easiest to apply the sand after planting and before