8
ARTICLE
“Cultivate”
HEMP
4 Tips to:
By Jeremy Daw
So far, 2014 has been a record year for California heat (among other places in the world).
While this may not be a bad thing for cannabis cultivators per se – some strains prefer a
warm climate – farmers who fail to properly prepare their crop will lose money and may
risk their plants. Here are some helpful hints on how to help your garden beat the heat:
Shade their roots: Just as a nice shady spot out
of the sun can be a nice respite for humans on
a hot summer day, so can a little shade work
wonders for plants. Don’t shade at the canopy
level (although you may want to do this with
young starts – see below), but at the roots,
where plants perform some of their most vital
functions. For best results, use a white sheet –
the light surface will deflect most of the sun’s
rays. Prop the sheet a few inches above the soil
or hydro layer to create a buffer of air in between. With this protective layer between your
plants’ roots and the hot outside air, they will
be much better equipped to handle the hot
summer sun on their canopy.
Diffuse light for young plants: While you generally won’t need to shade mature plants at the
canopy level – thus stealing the main source of
their energy! – young starts need some partial
shade to avoid frying in the hot sun. The goal
is to simulate nature – in the wild, young plants
tend to sprout below a higher canopy created
by more mature plants, so they’ve evolved to
grow best under partial shade conditions. To
simulate this scenario, use a diffusing cloth like
thin canvas or cheesecloth – some commercially available cloths have been designed for use
by nurseries for exactly this purpose, as well.
Mulch: Covering bare soil with a layer of mulch
has many varied benefits, of which keeping
plants cool is only one. Thus, if you’re growing
in soil you should always add a healthy layer
of mulch, even if you’re already shading at the
root level. If you’re not shading at the root level,
airy and fibrous mulches like pine can be the next
best way to create the shady buffer of air so critical to keeping plants cool. This step is especially
critical if you’re growing organically – not only your
plants roots but earthworms, mycelium and many
other organisms which symbiotically benefit their
roots will thank you for the respite.
Heatwave 911 – Ice: If all other methods prove inadequate in the face of blistering heat, you can
step up the assault on high temperatures with
some well-placed ice cubes during the hottest part
of the day. Here, care must be taken – dropping ice
cubes directly on the roots may drop the plant’s
temperature below its ideal range or even shock
the plant. But if dropped on top of a buffering layer (say, a layer of pine mulch), the melting runoff
from the ice cubes can warm to just the right temperature to be drawn up through the roots and
through the stalk to the stomata at the canopy
– thus cooling plants Zzfrom the inside out. Here
again a well-placed white sheet will redound to
great benefit, because the shade under it will encourage the cubes to melt at a steady rate as well
as preventing the cubes’ moisture from escaping
into the air above.
In conclusion, these techniques work best when
used together – using diffusing cloth to shade
young plants before putting them out, root-shaded
and mulched, in direct summer sunlight. If used
in tandem, these techniques can reduce water requirements and avoid having to use more expensive interventions, like ice cubes, at all.
9