Plant them in fibry loam and tough and fibry peat, with a liberal admixture of leaf-mould and well-decayed woody matter, to which add a thin top-dressing of similar material every autumn.
Preparing the bed the old-fashioned way is a lot of work, but a well-made bed will grow delicious asparagus for fifty years with only annual top-dressing and hand cultivation.
Soot forms a good top-dressing; it consists principally of charcoal, but contains ammonia and a smaller proportion of phosphates and potash, whence its value as a manure is derived.
Malt-dust is an active manure frequently used as a top-dressing, especially for fruit trees in pots.
Gypsum, or sulphate of lime, applied as a top-dressing at the rate of 2 to 3 cwt.
Per acre as a top-dressing in moist weather.
In the broad river basins the inundations deposit annually a fresh top-dressing of silt, thus superseding the necessity of manures.
The plant grows freely in good garden soil, preferring a deep welldrained loam, and is all the better for a top-dressing of manure as it approaches the flowering stage.