Shutters are sometimes used instead of mats in covering frames. They may be made of light lumber and may be of any convenient size. When used alone on frames they do not protect the plants nearly as well as mats. Sometimes shutters are used over the mats, which they protect from rain and snow.
Chapter XXI (Cultural Directions. Artichoke, Asparagus) gives information on the proper dates for sowing.
When flats are used in sowing cabbage, lettuce, tomato, pepper, parsley and other seeds, the operation should be carried out in the following manner: Fill the flat with soil moist enough to work well. Sprinkling while the soil is being turned may be necessary to secure the proper amount of moisture. See that the soil is pressed firmly in the corners and along the sides. With a straight-edge, make furrows 1« to 2 inches apart and ¬-inch deep, the first row being about « inch from the end of the flat. The rows should be parallel and neatly made. With an envelope, distribute seed at the rate of about 12 to the inch. Close furrows in the most convenient way; firm the soil with a block; water and place in the proper temperature. Fifty to 60 degrees Fahrenheit provides the best conditions for lettuce, cabbage and cauliflower, while 70 to 80 degrees is better for tomato and other tender vegetables. Figure 41 shows a flat of cabbage seedlings. A flat of this size should produce about 1,000 plants.
Fig. 41. Flat Of Cabbage Seedlings.
Proper temperatures must be provided for the growing seedlings. If too high, the plants will be spindly, soft and tender. Some fresh air should be admitted to the hotbed or the greenhouse every day. Water must not be used too freely, for excessive watering and high temperatures are certain to produce weak plants. Apply water in the morning, if possible, and try to have the foliage dry at night to avoid damp-ing-off fungi.
Some growers begin transplanting a few days after germination, but it is generally better to start the work in three or four weeks from sowing, or when the true leaves are forming. If many plants are to be pricked out, the work should be started promptly and completed as soon as possible, in order to prevent the plants from becoming spindly.
If flats are to be used, the work may proceed as follows : Place about ¾ inch of partly rotted manure in the bottom of the flat and fill with soil. See that the soil is firm over the entire box and especially in the corners and along the sides. With a leveling strip remove the surplus soil and leave the surface smooth. The holes may be made with a machine (Figure 37), or by the use of the transplanting board (Figure 36). When the board is used it should rest firmly on the soil over the entire surface; hold the board in place with one hand, and with the other punch the holes with the dibber shown in Figure 36. A boy will soon learn to do this work very rapidly. If the soil is in proper condition and the board and the dibber are used skillfully, every hole will remain open when the board is removed.
The seedlings should be watered at least 24 hours before being transplanted, so the tops will be dry and the work of transplanting be greatly facilitated. The soil will be moist enough for the plants to be removed without serious mutilation of the roots. The plants should be handled carefully and kept in orderly arrangement in order to save time in dropping. The flat which has been previously dibbled is placed lengthwise on the bench or the table. A bunch of plants is held in an orderly position in the left hand near the holes while the other hand drops a good plant into each hole, beginning at the left end of the far row, and leaning it against the side of the hole toward the side of the flat farthest from the worker. The plants are dropped in the same manner in each row of holes, all the plants leaning in the same direction. The observance of these details is of importance for speedy work. Boys and girls soon learn to drop the plants very rapidly, but it is better to have experienced workmen set the plants. This operation may be done very rapidly with thumbs and fingers or with the index of one hand and a small dibber in the other. Many gardeners make the hole with a small dibber, drop the plant and secure it at once. This is unquestionably the best plan when plants are 3 or more inches high, but the board method just described is much better for small plants when a large force of unskilled laborers is at work; it insures straight rows and a uniform number of plants in every flat.
If the soil was made sufficiently moist before planting, little or no water is needed immediately after. The boxes may be taken to the hotbed or the greenhouse or placed in the cold frame, as may be required.
After transplanting, the flats should be looked over every day and late in the spring twice a day and watered whenever necessary. Until established, ventilation should not be too free. Seedlings planted in cold frames during the early spring often need no ventilation for a week or more. After the plants are well started more air should be admitted and the amount of ventilation increased as the season advances and as the plants become larger and stronger. Cold drafts upon small tender plants should be avoided as much as possible. This may be accomplished by opening the sash on the side of the frame opposite the prevailing wind.