The Reh Method of Greenhouse 
Culture with Plastic Glass 
Frederick O. and Winifred Reh of Belle- 
ville, Illinios, have published a booklet of 
16 pages in which they list and discuss their’ 
method of growing plants (mainly Orchids) 
in their plastic fiber glass house. 
There are many who are building small 
greenhouses and both the type of house and: 
its operation. are problems. The Rehs evid- 
ently have many of these licked and in doing 
ie os come up with some new ideas as 
well. 
To quote from their forward, ‘““We want to 
stress the fact that the light which comes 
through our plastic glass panels is a pow- 
erful cosmic force. To utilize the optimum 
advantagees of this material it is imperat- 
ive to briing the trinity of plant ecology — 
light,, moisture and air—dinto a _ balance.” 
In any greenhouse, whether one covering 
arces or just the small hobby greenhouse, 
this trinity has always been a problem. Es- 
pecially is this so in the small house where 
the operator is often absence most of the 
time and where the conditions within the 
house can change rapidly. 
The writer has for some time been work- 
ing on a small greenhouse that will fill the 
need of a hobby-house —a house that can 
be operated so that it will not be a ”hobby- 
horse” instead of a hobby-house and one, 
too, that the owner can work elsewhere dur- 
ing the day without worrying and that he 
can sleep at night. 
First, the subject of light—the glass for 
the house. Outside of cost, and I under- 
stand the plastic glass costs nearly $1.00 
per square foot, it has many advantages. 
From the standpoint of cost, it can be erect- 
ed on a much less frame work — the panels 
can be even set into the soil a foot, thus 
saving the cost of a cement foundation and 
only the pipe supports need be put into 
cement. As the panels are some 4x8 feet 
in size, only a limited amount of supporting 
material is needed. Even the roof supports 
are not so costly. ; 
With plastic glass, the roof is made of the 
corrugated sections, 40” x 144”. The side 
wall of plain panels. As the Rehs point out, 
the mere use of plastic glass alone, is not a 
panacea. The other problems of heat, air, 
humidity must also be brought under con- 
trol. f 
Plastic glass has several practical advant- 
ages. It does not break in hail storms. Dua 
to the large panels, there is less air leaks 
as well as water leaks. It does not frost 
as does a glass roof. It does not burn fol- 
iage nor is shading necessary In summer. 
All these points are problems in the small 
hobby greenhouse. However, good light 
is the important factor and the Rehs have 
this to say, “Good light is a prerequisite 
for normal plant growth. Synthesis of plant 
foods and hormones (anabolism) takes place 
under light. The conversion of this energy 
into cell growth usually takes place at night. 
The better the light, considering parallel 
factors — such as air and water — the more 
efficient the plant-factory operates in the 
anabolic stage of metabolism, and more and 
better growth takes place in the catabolic 
stage. Some plants, such as Carnations, 
tomatoes, etc., need more and longer light 
exposure than others. (Tomatoes needs less 
than an hour of darkness to complete a 
metabolic cycle.) Most Orchids, in their 
native habitat, are attuned to a day and 
night cycle of almost equal lenght, the year 
*round”’. ’ , 
In the use of plastic glass, light is thor- 
oughly diffused, making it almost impossible 
to cast a shadow, a factor helping to a+ 
count for good plant growth. This results 
in it being possible to grow shapely plants 
even under the benches and with as good a 
result as those grown on the benches! 
The effect of ultraviolet rays on the color 
of flowers is especially benefited under 
plastic glass. Where shading is necessary’ 
on glass, several days of cloudy weather, 
upsets the normal reaction but with plastia 
glass, where no shading is necessary, this 
problem is eliminated. White Cattleyas de- 
velope a dark green color where under 
shaded glass it was a pale green. 
As stated at the start, plastic glass is not 
the entire solution to the problem. The 
circulation of the air, is very important. 
This is solved by using circulating heaters, 
controlled by a thermostat and an aquastat, 
Suspended from the roof. “It collects and 
circulates the cooling humid air from under 
the roof before the moisture condenses, 
and fans the air over the plants in the form 
ce a warm humid breeze, thus eliminating 
drip. 
The propeller fan-type heater, installed 
overhead, is being used in several large com- 
mercial greenhouses, the past 2-3 years. The 
heat is either hot water or steam, piped to 
the overhead unit, which is operated auto- 
matically and responds quickly to the slight- 
est change in temperature. 
Humidity and watering are important fact- 
ors in the regular type greenhouse but under 
the plastic glass house, with overhead circul- 
ating fans, over watering is not a fault, be- 
cause the circulating air in the house prevents 
condensation of moisture, in excess, on the 
plants. 
_ The night circulation of the air is very 
Important, too,-to prevent air layering and 
to carry away the waste gases released by 
the plants, especially when crowded as is 
the usual case in small houses. Damping- 
off results from lack of air circulation at 
night. In the fields, the air necessarily cir- 
culates but in a closed house, this does not 
take place and results in several bad factors. 
The Rehs grow Orchids, mainly. They 
seem to have worked out some very import- 
ant angles, especially for the small green- 
house. Anyone wanting their booklet can 
write them at Belleville, Ill.. enclosing $2.00 
We will appreciate letters from any one 
having experience on this problem. We are 
trying to work out a practical, inexpensive 
set-up for a small hobby-greenhouse and 
more information on this subject will follow 
in future issues, especially on the type of 
heater for the small house which still ig 
not worked out so as to be both practical 
and reasonable in cost. 
Iris cristata and lacustris 
The former Iris usually is lavender with 
darker spot and marked with yellow on the 
crests. I have gathered plants of this near 
Liberty, Ky., but it is also found locally in 
North Carolina, Georgia and Arkansas. 
There are variations in the colors, one 
being white and I would be pleased to hear 
from any reader who knows of areas in 
which it grows. These variations will be 
appreciated. Here in Michigan it grows 
all right but it will heave out of the ground 
if not well drained. 
I. lacustris is native of Wisconsin and 
found near Milwaukee the only place I 
know of. Are there any readers who know 
of this little Iris? 
OYSTER SHELLS A SOURCE FOR LIME 
The remark in Mr. Hannibal’s article in 
this issue of using crushed oyster shells is a 
suggestion that is of value. Many growers 
have difficulty in securing a form of lime 
and may use slack lime which tends to bake 
the soil. Crushed oyster shells are easily 
found at any feed store; they will not only 
provide lime but will also loosen the soil. 
SUBSCRIPTION PRICE $2.00 12 ISSUES 
375 
Haemanthus nutalense —J. C. Bacher, Ore. 
PANSIES FROM JULY PLANTING 
Seed sown the first week in July will make 
plant large and strong enough to be trans- 
planted to their permanent position by fall. 
Seeds sown the last of July can be wint- 
ered over in a frame and these will give a 
later bloom than the first planting. 
In transplanting be sure to press the soil 
well around the plant. The best Pansies 
are those grown in a rich soil and cow 
manure that is well decayed is ideal. , 
Where the Pansy planting is important, 
as it is with those growing plants for the 
market, the seed should be ordered in the 
spring, if new crop seed is wanted. The 
seed matures in June and not all of it 
is delivered by planting time, thus the early 
orders are naturally filled first. Many com- 
mercial growers are particular as to color 
blends but always buys the mixtures; where 
a pound or even a half pound is required 
it is always best to buy the varieties and 
thus get just what you need. 
THINGS YOU CAN DO IN JUNE 
Flower Seeds that can be sown: 
*Balsam 
*Cacalia (Tassel Flower) 
*Calliopsis 
Celosia (Cockscomb) 
*Cllitoria 
*Cleome 
Coleus 
*Cosmos, for late flowering 
Didiscus (Blue Lace Flower) 
*Gaillardia 
Helichrysum (Strawflower) 
*Marigold 
*Moonvine 
Morning Glory (Ipomoea) 
*Portulaca (Moss Rose) 
*Tithonia 
Torenia (Summer Pansy) 
Zinnia 
*Sow seeds in open. 
CHENOPODIUM BONUS-HENRICUS 
Good King Henry; Mercury; an old-time 
herb and a substitute for Asparagus; resemb4 
les it in flavor and more easily grown. 
It is 12-18 inches tall and is best in a 
warm sunny position. Try growing it; it 
is a perennial so can be started now. 
