Question: We just completed building our home greenhouse and need to start begin some kind of schedule for planting and all the other task associated with having a small greenhouse in the backyard. Where do we start in July? Michael, Binghamton, New York
Answer: Micheal, welcome to the home greenhouse club! It is a blast! If you were visit me in New York, some weekend during July, you would find me taking cuttings of geraniums – a favorite greenhouse plant for winter flowering. Geraniums may not sound exciting to many a greenhouse growers but since there are hundred of kinds, a collection of them offers endless possibilities for adventure and education.
Last year a friend of mine had over 130 different varieties in his greenhouse and is continually adding more. Among his many choice varieties are some he has been successful in flowering that have never been known to bloom for him in pots before.
Geraniums Easy To Root
Geraniums are easily rooted from cuttings at any season of the year but this is a good time to take cuttings for plants that will reach flowering size next winter. Most varieties root in 2 to 3 weeks in coarse sharp sand, in a mixture of half peatmoss and sand, or in vermiculite. Some species take longer to root and others are especially difficult to propagate since they are short-jointed and do not make growth of sufficient length for a good-sized cutting.
It is best to select firm but not woody growth up to 4 or 5 inches long for fast rooting. Such cuttings need plenty of moisture, light shade and humidity. Shorter cuttings are more easily handled. Geraniums are not the only plants to propagateg this month. Now you can take cuttings of late chrysanthemums, lantana, poinsettias. cacti and succulents and planting seed of winter-flowering marigolds. sweet alyssum, primroses, sweet peas and cyclamen. We are also repotting amaryllis and benching winter-flowering carnations. It is much easier to build them up into strong plants in the greenhouse than to leave them out-of-doors for the summer.
Shifting The Rooted
Within a month, the seed and cuttings started will be ready to shift into 3-inch pots. I normally use bagged mix but sometimes make a mixture of peat moss, 1/3 sharp sand and add in some cow manure. By fall, plants will be transferred to 4 or 5-inch pots, depending upon the size and condition of the roots. This time the soil used will be a little coarser to provide the free drainage and oxygen the roots will need to grow vigorously.
There is no wasted space in the greenhouse and you will find something in bloom all year as the wise greenhouse gardener selects material according to season of bloom. For example, our freesias are out of this world. They were started from seed several years ago and now only the “selected” corms are used. In flower at the same time are camellias in variety, then gardenias, a lemon and orange tree, and two species of cereus.
While all of the plants mentioned above are grown in benches, shelves, hanging baskets and even the space under the benches provide room for still more.
You might wonder how it is possible to grow so many plants at various temperature requirements in a single greenhouse. The answer is very simple. The greenhouse often heated by a heater placed at the far end. The space near the heater runs about 10 degrees warmer than the far end and there is about a 5 degree temperature difference between the floor and the shelves. So, by selecting the proper location, all of the plants are happy together.
July Greenhouse Tips & Checklist
by C Ernest
