If it is found that some of the plants have not started by the middle of June, it is best to replace them with growing plants of the same age, which should have been kept in a reserve bed for this purpose. If this replanting is done carefully, so as not to mutilate any of the roots, and on a cloudy day, it is best not to cut back the tops very severely. Unless a copious rain sets in soon after planting, the roots have to be heavily watered, after which they will keep on growing at once without suffering any setback.
The formerly all but universal practice was to cover the roots with manure after the stalks had been removed in the fall for fear of frost injuring or killing the roots. In sections where winters are very severe this may still be desirable, as may be seen from the statement of so keen an observer as Professor J. C. Whitten, of the Missouri Experiment Station: "Most writers advise applying dressing of old fine manure during the growing season when the plants can use it. In our soil better results are obtained by applying it in winter. It prevents the soil from running together and hardening, and also prevents the sprouts from coming through, as they otherwise often do, too early in spring, and becoming weakened by subsequent severe freezing."
As the reverse of this plan, M. Godefroy-Leboeuf, the famous French authority, recommends "to clear out of the trenches the soil which has fallen into them from the sides of the mounds, and also remove from above the stools a portion of that with which they were covered at the time they were planted--say, to a depth of one and one-half inches--so that the action of the frost may open the soil and that the rain may penetrate and improve it; also that during the first fine days of spring the sun may warm the surface of the soil and penetrate as far as the stools. There is no fear that the action of the frost should hurt the plants. Asparagus will never freeze as long as the stool is covered with a layer of soil one and one-half to one and three-fourth inches in depth."
If the rows are not less than four feet apart a crop of some other vegetables may be raised between them. Beans, dwarf peas, lettuce, beets, or any kinds which do not spread much, are suitable for the purpose. These by-products will help considerably toward paying the cost of cultivating the main crop, besides having a tendency to keep the soil cool and moist, a condition of no little importance to the asparagus.