seems to be one of the easiest ways of increasing yield, growth
speed, and quality in a well vented space, with or without
elevated CO2 levels. Just prepare a tea of worm castings, fish
emulsion, bat guano, or most any other plant food right for the
job and feed in vegetative and early flowering stages. It is not
recommended for late flowering, or you will be eating the
sprayed-on material later. Stop foliar feeding 2-3 weeks before
harvesting. Wash off the leaves with straight water every week
to prevent clogging the stomata of the leaves. Feed daily or
every other day.
Best times of day
to Foliar feed are 7-10Am and after 5 in the evening. This is
because the stomata on the underside of the leaves are open
then. Also, the best temperature is about 72 degrees, and over
80, they may not be open at all. So find the cooler part of the
day if it is hot, and the warmer part of the day if it is cold
out. You may need to spray at 2AM if that is the coolest time
available. The sprayer used should atomize the solution to a
very fine mist; find your best sprayer and use it for this. Make
sure the PH is between 7 and 6.2. Use baking soda to make the
solution higher PH, and vinegar to make the solution lower PH.
It is better to spray more often and use less, than to drench
the plants infrequently. Use a wetting agent to prevent the
water from beading up, and thereby burning the leaves as they
act as small prisms. Make sure you don not spray a hot bulb;
better yet, spray only when the bulb has cooled.
Perhaps the best
foliar feeding includes using seltzer water and plant food at
the same time. This way, CO2 and nutrients are feed directly to
the leaves in the same spray.
Foliar feeding is
recognized in most of the literature as being a good way to get
nutrients to the plant later when nutrient lockup problems could
start to reduce intake from the roots.
WARNING!: It is
important to wash leaves that are harvested before they are
dried, if you intend to eat them, since they may have nitrate
salts on them.
NOTE: One grower
who reviewed this document comments: "Fish emulsion smells. Bat
guano could be highly unsanitary. Stick to the Rapid-Gro, MgSO4
(Epsom salts), hydroponic trace element solution. Nitrate salts
(The "N" in NPK) are unhealthy to smoke. Personally, I never
Above is a great
comment, and there is great wisdom in an organic, non-toxic
garden. Personally, I use only CO2 on my indoor hydroponic
plants, and never folar feed. It simply does not seem to be
necessary when using hydroponics.