A New Greenhouse Gardening Season

Yes, the summer is coming to a close, but as a hobby greenhouse owner, I am looking forward to a new gardening season. The most difficult decision is which plants to bring in for the winter. My cool greenhouse maintains a night temperature of 40º-45ºF (5º-7ºC) so the selection is made from the frost-sensitive plants in the garden. Patio container plants such as abutilion, datura and lantana have provided continuous color all summer and with proper care they will be flowering again next year. A fall pruning is necessary before they are brought into the cool greenhouse.

Fuchsias and geraniums are among the easiest plants to winter over in the greenhouse. Although August is the best month to take cuttings from these plants, fall cuttings can still be taken. A soil cable heating bed in the greenhouse will provide the required bottom heat to root these cuttings.

The parent plant is lifted and the stems cut back to within six inches from the base. I usually remove all the leaves because they will discolour and eventually fall off. Then, the well-developed root system is cut back to six inches from the base. This extensive root system is no longer required to sustain the plant growth. The parent plant is potted in a sterilized potting soil in the smallest pot that can hold the remaining roots.

When placed in the cool greenhouse these plants will have a dormant or resting period. During this time is when roots continue to develop but there is very little growth in the leaves. Watering is decreased, but do not let them dry out completely.

Before the garden plants are brought in, consider giving the greenhouse its annual cleaning. Fall seems to be the best time because during the summer months, pests find the greenhouse conditions very suitable for breeding. It is also the time when the greenhouse has the least amount of plants that have to be moved.

Fall Bulbs for the Greenhouse

In September plant some hyacinths and short varieties of tulips and daffodils in containers. They are stored under the greenhouse bench or a frost free garage. Check regularly to see if some watering is required.

Fall Greenhouse tips:

• A recommended cleaning solution for glass greenhouses is a mixture of hot water and a disinfectant. Benches, shelving, plastic trays, pots and baskets should also be cleaned thoroughly.

• Note: For a Polycarbonate greenhouses use a mild dishwashing soap and lukewarm water.

• As a preventative measure against disease and pests, any plant brought into the greenhouse should be washed with Safer Insecticide Soap.

• To prepare for the winter, check to see if the heater, circulating fan and maximum-minimum thermometer are in good working order.

• In the colder climates a single glazed greenhouse can be insulated with a clear plastic liner. This greenhouse chore does take some time but certainly will save on the heating costs.