This section is from the book "The Gardener V1", by William Thomson. Also available from Amazon: The New Organic Grower: A Master's Manual of Tools and Techniques for the Home and Market Gardener.
No vegetable cultivated in our gardens is more valued than Asparagus. It may not be found in many small gardens, but it is quite indispensable in every garden of any importance. Its successful culture is not a recently acquired accomplishment. Probably many of your readers may think in this respect we are going back rather than forward; as many Asparagus beds might have been found twenty years ago that would equal any to be seen at the present time, if the latter are not decidedly inferior to the former. If such is the case, there are no good reasons why it should be so, as our appliances in every shape, including tools, manures, and knowledge, are all supposed to be improved; but probably less attention is paid now to making the beds and preparing the ground than many old hands were in the habit of devoting to this part of its culture. No plants are easier raised from seed than Asparagus, and it will grow readily on any good piece of soil which has been merely stirred and manured on the surface; but its progress here will not be lasting, and after a year or two the crop will gradually dwindle away, until it is not worth the ground it stands on.
Roots which we have seen bearing well when about twenty years old, and that on the same piece of ground on which they were first planted, had the ground thoroughly prepared for their reception at first; and this must still be the case if good and lasting results are desired. Although Asparagus is often thought to be particular as to soil, it really is not; but whether the soil be heavy or light it should be well prepared, and success in most cases is sure to follow. We have had quantities of old sand carted to make "natural" Asparagus beds, and devoted a good deal of attention to their formation too; but the result was no better from this than we had from others planted in ordinary garden-soil well tilled. A very wet place or soil for the bed or plantation must be avoided, but any ordinary dry land may be selected; and the soil should not be less than 2 feet deep - if it is 3 all the better; and in beginning to make it ready for a permanent Asparagus plantation, it should be trenched down to the first of these depths, and the second if possible. If the subsoil is very hard, keep it in the bottom, only loosen it well up, and the worse it is, mix the more old vegetable refuse with it.
If good manure can be put in at the same time it will not be lost.
After trenching the required space over in this way, a coating of good manure should be placed all over the surface and dug in deeply, and a good sprinkling of salt may be thrown over it previous to burying it. This will help to clear the soil of insects, and nourish the young plants as well; but more about salt by-and-by. The best of all ways to propagate Asparagus is from seed, and the proper time to sow it is early in April. Every year we sow a small bed of seed at this time, and we have always a quantity of young plants in hand ready for any purpose if wanted. The seed is sown in drills about a foot apart; only a small quantity of soil is placed over the seed, and it never fails to grow. During the summer a few of the plants may be drawn out if they are very close together; but with 2 or 3 inches between them they develop nice little crowns the first season, and the shoots run up 2 feet or more. The hoe is run between to keep weeds down, and when the stems have withered in autumn, they are cut over and a slight covering of light manure placed over the crowns. Like this they remain until March, when the manure is taken away, and the young plants soon afterwards begin to push up fresh shoots.
It is just when these are seen peeping through the surface of the soil that the roots may be transplanted with the greatest success. So that, besides being the best time to sow the seed, early in April is also the best time to plant. Where the roots have only to be taken from one part of the garden to another, we would make sure that growth had begun before shifting; but were we buying in roots from a nursery, and they had to come a considerable distance, we would try and get them about the end of March, or just before growth was fairly started. They would get little or no check then - a thing at all times to be avoided, as Asparagus roots do not bear being much dried up. For this reason we would recommend every one to raise their own plants from seed, when they can be transplanted on a suitable day, and in the shortest time. Following this plan, the seed would be sown twelve months before it is necessary to have the permanent bed ready; but the ground may be trenched some weeks before planting, and when the time comes for this operation, it will only have to be decided which way to plant. Two ways may be chosen - either make the ground into beds, or plant in rows without forming a bed of any kind; of the two ways, we decidedly prefer the latter.
It is much the more economical for space, and gives the finest produce. In fact, we like the row planting plan so well that nothing will be said about the bed system, as we have given it up, and do not intend taking to it again. I believe the greatest of our authorities on Asparagus call our plan of planting the "improved one," and it is so. In making the rows, the plants should stand 2 feet apart each way. Many add a foot more to this, but we would only advise this distance where ground was plentiful. The wider the plants stand, the finer does the produce generally become; but fairly good produce, which need be despised by no one, may be had from plants at 24 inches and 30 inches apart. The soil having been previously well prepared, no great digging need take place at planting time. On the site of each plant, a patch of soil about 1 foot square, and three inches deep, should be taken out with the spade. The roots should then be placed singly in these with all their strong fibres spread out, putting the soil gently back over them again, and finishing up with treading firmly all around the crown, but not on the top of it. Row after row may be put in like this, and the soil levelled down after all has been finished.
The young growths will soon show where the rows are; but as many may not be able to afford so much ground to remain empty between them, a single row of Spinach, Lettuce, or any close-growing crop may be run between each row of Asparagus. This may be done for two or three years after planting, and then it is better to leave the Asparagus in full possession of the ground. For some time after planting, the roots will require no more attention; but as soon as weeds appear they must be destroyed with the hoe, and frequent hoeings throughout the season will keep the ground clean and open. Somehow or other Asparagus beds or plantations are always inclined to become very dirty and weedy; it adds much to the wellbeing of the plant, therefore, if the weeds are never allowed to make any headway. As the situation of the Asparagus plantation should always be open, the young stems the first and second years may probably be blown over : when they are seen to go in this way, a stake about 2 feet high should be put to each, and one or two ties will keep them secure. Each season as the canes ripen and wither they should be cut over. A small handful of salt shaken round each plant, and then a light covering of manure, should be placed over all.
About the end of March, when the heads are beginning to push up, the manure may either be cleared off or left on. We generally leave it on, and another handful of salt is thrown over each plant as growth is commencing. The same dressing may be given them when cutting the produce ceases. No manure is better than salt for Asparagus, and the applications of it we have named, and the covering of manure given in autumn, will keep any plantation in good bearing condition for many years. We have cut heads from Asparagus when the roots were only two years old, had good stems from it at three years, and a full crop the fourth season. When to cease cutting should be regulated by situation and climate. In late sunless districts, late cutting may prevent the crowns from developing fully and maturing thoroughly in autumn, and this oft repeated will soon cause degeneracy. Here we usually do not cut long after the Peas come in, which is early in June. With regard to forcing Asparagus, little need be said at the present time; but by way of preparing for this, I may say that well-grown roots will always yield freely to forcing from the end of October onward.