Re: [CH] 2 liter soda bottles

Lynn Edwards (ledwards@crl.com)
Tue, 28 Apr 1998 20:46:39 -0700

Doug forwarded the following about using 2 liter soda bottles in a ring around
pepper plants:

> > go to your recycling part of the grocery store and buy
> > a bunch of 2-litre clear plastic pop bottles for the 5 cent refund.
> > Remove the labels, fill with water, cap, and band together in a circle big
> > enough for the growing plants.  Tomatoes, peppers, and eggplants can be
> > planted a few weeks earlier with this method...

Watch out!  This idea sounds good, and so I tried it a couple years ago on 10
tomato plants.  Within hours I had many dead tomatoes and others that were so
severely damaged that I had to replace them with spares.

Try this little experiment.  Fill a two liter bottle up with water and cap it.
Set it close to a pepper plant and back off several feet and view the pepper
through the bottle.  Notice the greatly magnified leaf sections as you move
about while watching the plant through the bottle.  This is especially true if
looking down on the plant through the curved body to neck transition of the
soda bottle.  The soda bottle is forming a crude magnifying glass with the
focal point quite a few inches beyond the far side of  the bottle.  With a good
magnifying glass you can light paper on fire in just a few minutes.

In my locale in the springtime the sun angle is just right to shine down onto
the plant through the neck area of the bottle where it started burning into my
poor tomato seedlings.  As the sun arced across the sky it burned a narrow line
across each plant, lopping off branches, leaves,  and even main stems as it
went.  It looked as though they had been cut with a welding torch. Your plants
won't stand a chance if the sun comes out from behind a cloud, even if just for
a few minutes.

If you're intent on using soda bottles then be sure to sand a rough surface
onto the bottles to diffuse the light before subjecting your peppers to this.
This prevents any focusing and eliminates the damage.  I tried this too.  The
end result was that the sanded soda bottle housed plants did no better than
plants guarded with an ordinary circle of 6 mil plastic.  I compared soil
temperatures, as well as air temps inside the bottle ring in full, partial, and
no sun conditions with no significant difference between them.

Two liter soda bottles are cheap but the labor effort to sand them is not
trivial.  Try it.  The plastic is tough to roughen up and the sandpaper loads
up quickly.  For me the ring of six mil plastic is more effective and much
easier.  Not only that but the plastic sheets fold down flat for easy storage
till the next season.

Lynn Edwards
www.crl.com/~ledwards