Owners of small "commercial" greenhouses are alert for ways to save labor and stretch their producing areas. Both ends can be served by starting annuals (including bedding plants) and tender perennials in flats in late winter or early spring, and moving them to cold frames as soon as freezing - weather is past. Once the flats are moved out, the greenhouse space can be filled with other things.



Selling plants in flats of a dozen to 100 or more avoids the work of potting. Most small plants retail at about 50 to 60 cents per dozen, with the possible exception of double petunias, which usually run to twice that much. Potted singly, these same plants retail for 25 to 39 cents apiece, but to rate that price range the potted plants will also have to be grown a bit larger than is necessary in flats.

Grow the plants in full sun in a cool house, to keep them bushy. The following are four of the most popular plants small greenhouse owners have found to be steady, profitable items. The cultural hints I offer are, of course, based on the timing of the seasons, weather, etc., in my area. Be sure you take your own local conditions into consideration in applying my recommendations (or anyone's) as to seeding time,etc.

Alyssum

Although sweet alyssum (Lobularia maritima) is a tender perennial, it is treated in the north as an annual. It can be started in the 50-degree greenhouse. January seed-planting should assure salable plants in April. Culture approximates that of ageratum, and the sweet alyssum can be propagated by cuttings and rooted in any growing media. If your greenhouse is crowded, move the flats of sweet alyssum to the cold frame as soon as danger of freezing is over.

Impatiens

Impatiens - often called patience, busy Lizzie, or touch-me-not - has a translucent stem. Leaves are green, reddish, or variegated green and white. These attractive little plants produce gay flowers of white, pink, red, or purple.

Any friable soil, in 65-degree temperature, is well adapted to impatiens. Seed culture is much like that of coleus, and you can grow impatiens from seed to bloom in 6 months. Cuttings taken in January and rooted in any media will be ready for 2- or 3-inch pots by April.

Thrips and aphids are the most bothersome pests and can easily be destroyed by malathion.

Marigold

The brilliantly colored marigolds that grace nearly every garden can become a source of profit for the home greenhouse grower. Sow the seed in ordinary soil in late February. Pot up as growth indicates, and you will have salable plants by mid-May. If you want the extra greenhouse space, transfer the marigold flats to a cold frame or lath house once the danger of frost is over. In this way, they occupy space for only 6 to 8 weeks. A few more weeks in the cold frame and they are ready to be sold in the same flats they were grown in.

Petunias

Petunias are among the best spring sellers. Hybridizers have done so much work on breeding diverse varieties that it is difficult to recognize the old petunia form in some of the new double beauties. Grow your petunias from the best seed you can obtain; it costs very little more than inferior seed and assures you petunias different enough to sell at a premium to gardeners in your community or to a retailer.

Sow petunia seed in mid-January for flowering plants by the first week in May. Transplant the seedlings to flats of average greenhouse soil, spacing them about 2 inches apart. They can be grown on and sold directly from these flats; or, as they crowd one another, you can pot some of them in 2- or 3-inch pots.

Petunias do well in 65 to 75 degrees F. and can stand full sunlight. If you are short of greenhouse room, shift your petunias to the cold frame as soon as hard frost no longer threatens.

Aphids are their worst trouble, but in this case, too, malathion makes short work of the pests.

Enjoy growing and selling these delightful plants!