To put spring into its proper perspective, it sometimes seems as though we need to reread Henry Van Dyke's comment on the subject, "The first day of spring is one thing, and the first spring day is another. The difference between them is sometimes as great as a month." Each of us needs to remind himself that although daffodils may be breaking through the turf in response to spring sunshine, four to six weeks must pass before night temperatures outdoors are sufficiently mild to meet the needs of many of the tender flowers and vegetables we grow in our summer gardens.
This allows us time enough to grow many plants indoors to an ideal size for setting out into the garden. Perhaps the most important lesson the impatient gardener must learn is that plants started too early in the spring may become stunted while waiting until the weather warms enough to set them outside. Once their stems become tough and stringy or tall and gawky, they have lost the race for beauty. Even though put into the garden, they must be cut back and forced to make new growth. It is far better to time your planting so that husky young plants are ready for the garden when you set them out.
Also, the young plants benefit greatly by spending a transitional period in a coldframe. A temporary one made of boards and covered with old storm windows is perfectly suitable. The idea is to help the plants adjust to outdoor living. A coldframe which is heated only by the sun should be propped open during the day but closed at night. As the plants toughen the sash can be removed entirely.
One of the most rewarding developments in the growing of young plants has been the invention of the peat pot. Available in many sizes and shapes, peat pots are familiar to nearly all gardeners who have purchased commercially grown seedlings. They are of particular value to the home gardener because they are lightweight and promote strong growth. Since the plants' roots grow through the sides of their pots, the entire pots are set into the ground without root disturbance.
Sow two or three seeds into each pot. When they sprout, pull out all except the strongest one. Tomato plants are especially easy to grow by this method. Use 4-inch pots so that there will be plenty of room for the fast-growing plants to achieve as much growth as possible before going into the garden. An intriguing variation of the peat pot is the peat wafer that, when moistened, expands to serve as both pot and soil.
Another innovation that is becoming increasingly valuable to the home greenhouse owner is the use of "soilless soil." This is sold under several trade names and consists of a mixture of peatmoss and vermiculite or perlite. It is light-weight and free of weed seeds and diseases. Because of its open texture, it allows aeration while maintaining ample moisture. Such mixtures are also uniform from bag to bag and are easy to use and store. Of course, they need to be moistened before use and since they contain practically no nutrients, plants must be fed regularly. Feeding can be done with a liquid or dry fertilizer. Last year I used a peat moss vermiculite mixture combined with a slow-release fertilizer in window boxes and had spectacular results. Summer care was limited to watering and picking off dead flowers.
April's chores in a home greenhouse include careful attention to watering as well as to providing additional shade for those plants that need it. A very light cloud-like application of a shading compound helps to keep temperatures from rising excessively.
This is also a good month to take cuttings of many kinds of plants. The star of Bethlehem, Campanula isophylla, should be started from cuttings now to make flowering-sized plants for next fall. Chrysanthemums should also be started from cuttings this month and in May to provide a great number of flowers for next fall with a relatively small amount of effort.
A number of bulbous plants can be started this month, nearly all of which will yield years of enjoyment. The Amazon lily, Eucharis grandiflora, bears clusters of 2-inch fragrant white flowers intermittently through the year. The Scarborough lily,Vallota speciosa, has clusters of 3 to 4-inth bright red lilylike flowers in the fall. The Jacobean or Aztec, lily, Sprekelia forrnosissima, bears dark red orchid-like flowers in summer. Most blood lilies or haemanthus bear 6 to 12-inch 'ball-shaped clusters of starlike, red or pink flowers in late summer or early fall. Clivias have clusters of orange-red lilylike flowers in midwinter.
Fancy-leaved caladiums started now yield colorful foliage all summer and tuberous-rooted begonias come in every color except blue and blossom all summer. The Peruvian daffodil or ismene Hymenocallis calathina, bears clusters of 3 to 4-inch fragrant, creamy-white flowers about one month after planting. Tuberoses, Polianthes tuberosa, especially the double white variety, The Pearl, bear spikes of fragrant flowers in late summer and early fall. Fairy or rain lilies (zephyranthes) bear 2 to 4-inch white, pink, rose, yellow or salmon flowers during the summer and occasionally at other seasons as well.
The preceding article was published in the April 1972 edition of Horticulture magazine.