A question new greenhouse owners have often asked us is: “What shall I grow”? The answer depends almost entirely on the personality of the person involved.
But one governing factor is the temperature at which the greenhouse will be maintained during the cold months.
The beginner who attempts to grow all types of plants in a one-temperature house is sure to be disappointed.
Ideal Night Temperatures For Plant Growth
The night temperature at which the house can be maintained during very cold weather (10° to zero or lower) is the chief factor in determining what can be grown with real success.
The range of plants that thrive under airy given temperatures (allowing a rise of at least 10° degrees Fahrenheit in the daytime) is surprisingly large.
Each group includes many flowers satisfactory for cutting as well as a number desirable as permanent decorative specimens for pots or tubs, indoors or out.
Group I
Plants requiring or doing best at a minimum night temperature of 45° to 50° degrees Fahrenheit can survive an occasional exposure to 40° degrees Fahrenheit.
But if this occurs often, they will sulk and resent retarded growth and restricted flowering. Therefore, the required minimum should be consistently maintained.
Group II
The same holds for Group II —plants that need a minimum night temperature of 55° to 60° degrees Fahrenheit.
Group III:
Consisting of plants of tropical origin—will not be happy with night temperatures averaging below 60° degrees Fahrenheit.
Most of these will overwinter at a cooler temperature in a semi-dormant condition, but as they lack decorative value in this state, it is more rewarding to maintain their required minimum night temperature at all times and so keep them in good growth.
Considerations For Flowers For Cutting
Flowers for cutting? Another point to consider is whether flowers for cutting are important. If so, they definitely should be planned for.
In a fairly large greenhouse, such flowers as carnations, chrysanthemums, and snapdragons are usually grown on the benches or in-ground beds, but it is perfectly practical to handle them in large pots, giving them space as needed by shifting them as they grow.
Choosing Plants For Small Greenhouse
Usually, in a small house, plants of various kinds—some desirable for their flowers and others for their decorative foliage or interesting growth habits—prove more generally satisfactory than those grown to provide flowers for cutting.
Many of them may be moved into the house to be enjoyed to the full while in bloom and then returned to the greenhouse.
During such sojourns, they should be given extra care regarding watering, ventilation, and, as far as possible, temperature.
We often have seen flowering plants (that would have remained in full beauty for weeks in the greenhouse) dry their flowers and even the unopened buds when grown in the house.
They would then lose the luster of healthy foliage from being transferred to higher temperatures and lower humidity.
44659 by F F. Rockwell And Esther C. Grayson