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.
The Hollyhock is not so generally grown as its decorative qualities entitle it to. When grown amongst shrubs in situations moderately sheltered, few plants produce a finer floral display during the autumn months. The great drawback to its cultivation is the liability of the plants to get broken with the winds; but if secured when 18 inches high to suitable stakes, this objection is at once got over. At planting-time give each plant a few spadefuls of rotten manure, and if possible a little fresh soil; press the earth firmly round the plants; and if the ground is dry, give a good watering. In due time stake each plant, and as the stems advance in growth, secure them thereto with strong ties of matting. If the above simple hints are attended to, the result in most instances will be satisfactory.
When Hollyhocks are grown for exhibition, they must have a plot of ground devoted to themselves; let the situation be as sheltered as possible, but not near to anything that would in the least obstruct the noonday sun or a free circulation of air. To produce spikes such as are seen at some of our horticultural shows, requires a rich soil. To secure this, let the ground be trenched in autumn, adding, as the work proceeds, a liberal supply of good manure. When the trenching is complete, give the surface a dressing 2 or 3 inches thick of the best manure procurable; the winter rains will wash the best parts of it into the soil, and when planting-time comes, a slight forking is all that is required to make the bed in readiness to receive the plants. The plants should not be put out until all danger from severe frost is past, say the end of March or beginning of April. Let the plants stand 3 feet apart in the lines, and 5 feet from line to line. When finished planting, if the ground is moderately dry (which it should be, as it is a bad plan to plant when the soil is over-wet), make the surface rather firm by giving the whole a gentle treading with the feet.
Place at once over each plant some Spruce or other evergreen branches, as a protection against frost and cutting winds; as if they get frozen to any extent, the spikes are never so fine. As soon as all danger from frost is past, remove the protection, examine each plant, and see that all are firm in the soil. Let only one stem rise from a plant, and nip out all laterals as they appear. Never allow the plants to suffer for want of water; and as soon as flower-buds are formed, mulch the beds with rotten manure. I prefer this to giving manure-water, as the latter, unless applied with judgment, has a tendency to make the plants grow by fits and starts, thereby causing irregularity in the build of the spikes, a fault which neither length of spike.nor-size of blooms will compensate for. In most instances two flower-buds will start from the axil of each leaf; nip out the smaller of the two; and in any case of crowding, thin to the requisite number. During the three weeks preceding the show, the spikes must be protected from rain and strong sun. This in the case of the Hollyhock is not so readily accomplished, but it is necessary to the production of clean spikes; and the cultivator must not neglect it, as by doing so he will destroy his chance of attaining the end in view.