Planning ahead is important in any type of gardening. In greenhouse gardening, it is doubly so because the non-producing areas— scarcely noticed outdoors—are as conspicuous as sore thumbs in red flannel.
Several plants that are easily grown from seed may be started now to provide abundant color for winter.
Ideal Showy Plants For Winter
Cineraria, calceolaria, and schizanthus are three showy plants ideal for winter flowers in the greenhouse.
Sow seeds in August in loose, sterilized soil, preferably in a propagation box or case kept at 60° degrees Fahrenheit.
Transplanting
Transplant as early as possible into flats of sifted compost, adding one-third of sharp sand by bulk. Grow at about 50° degrees Fahrenheit.
Shift from flats into 3-inch pots, using the same compost-sand mixture but adding a pint each of complete fertilizer and bone meal to each bushel of soil. Repot as needed.
Fumigation or Spraying
Weekly fumigation or spraying to prevent aphids is essential in the culture of these three standard greenhouse plants.
Other seeds that may be started in August are mignonette and wallflowers for early spring bloom and Beauty of Nice stocks for late winter color.
Bulbs and Corms For Winter Beauty
Bulbs and corms also bring winter beauty to the home greenhouse. The first of these, perhaps, is the freesia, which gives both delicate color and fragrance to the greenhouse and flower arrangements.
August is the month to pot the tiny freesia corms in a mixture of two parts rich garden loam and one part sand. Add a pint of bone meal to each bushel of the mix.
Half a dozen corms may be placed in a 5-inch bulb pan that has been well-crocked to ensure good drainage. Water well and place in a cold frame.
Mulch them with 3” inches of dried hardwood leaves, excelsior, or other material. Remove the mulch as soon as top growth begins.
For Cool Greenhouse
Bring the pots into a very cool greenhouse before the first frost and continue growing in a cool house— just above freezing is ideal.
The unheated potting shed adjoining our greenhouse has proved ideal for growing borderline plants like freesia.
Other bulbs and corms to start in August are the following:
- Calla-lilies
- Lachenalia
- Brodiaea uniflora
- Alstroemeria
- Auratum regal lilies
Geranium Cuttings
Cuttings of geraniums may be started now to provide husky, blooming plants to set out next spring. Select the well-matured tip growths that have begun to harden and cut just below a leaf joint.
Cut at a slight angle so each may be readily inserted into the rooting medium. Heliotrope, fuchsia, lantana, and many other tender shrubs, such as rosemary and lemon verbena, may also be propagated from cuttings this month.
Good Soil
Soils are most important in greenhouses. No greenhouse—regardless of how good its design or the materials from which it is made—is better than the soils used in it.
Like most other things (except love, laughter, and green thumbs), soils wear out with use.
The soil in benches, ground beds, or pots is subjected to much more intense use than soil in any garden.
To ensure a ready supply of good soil for the coming winter, the greenhouse owner will do well to start making compost right now, earmarked for that purpose.
Like good elderberry wine, good compost needs a ripening period before it is at its best. Likewise, the bacteria that help to create good soil require time to do their job.
44659 by F. F. Rockwell And Esther C. Grayson