This section is from the book "The Gardener V3", 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.
It is scarcely time yet (February) for getting in the general ruck of garden seeds, though in dry warm soil many kinds may be sown, at least by the end of the month, with great propriety. Now is the time to calculate and procure the quantities to be sown. Indeed, this should be seen to before the soil is prepared, so that ground intended for the various crops may be properly treated. In giving directions for choosing seeds, the general rule is to say how much of this, that, and the other thing will be required for a quarter of an acre, half an acre, and so on. Such advice only serves to puzzle. The fact is, no two individuals' wants are the same, and hence a selection of seeds which might fit one person very well would be of little use for another. What I propose is, to give as near the amount of space required by a given quantity of seed, and by this means each person will be enabled to calculate to a nicety the seed required for his own individual wants.
Beet - 1 oz. will sow a row 50 feet long.
Broad Beans - 1 lb. will sow a row 60 feet long.
French Beans - 1 1/2 lb. will sow 60 feet.
Carrots - 1 oz. will sow 130 feet.
Cress - 1 oz. will sow 20 feet of a row 4 inches broad.
Leeks - 1 oz. will sow a bed 5 feet by 5 feet.
Lettuce - 1/4 oz. will sow 50 feet.
Mustard - Same as Cress.
Onion - 1 oz. will sow 40 feet.
Parsley - 1 oz. will sow 50 feet.
Peas - 1 lb. will sow 30 feet of a drill 5 inches broad, of the small, and 36 feet of the large sorts. Parsnips - 1 oz. will sow 100 feet. Potatoes - 1 peek will plant 100 feet if the seed is good, and cut to 2 eyes to a set only. Radish - 1 oz. will sow 20 feet. Spinach - 1 oz. will sow 60 feet. Turnip - 1 oz. will sow 100 feet.
Cabbage, Cauliflowers, Savoys, and all the Brassicas should be got in packets, as a very small quantity of seed will raise enough for most gardens cultivated by amateurs. Indeed, it is advisable to get the plants from the nursery or from some obliging friend, and so save a great amount of worry.
In some collections of seeds offered by enterprising seedsmen, I have sometimes seen 3 oz. of Cabbage included for gardens of 1/4 of an acre ! Why, it is more than enough to raise plants for the whole ground; of Celery and all other vegetables not included above, a moderate packet is sufficient. A mere pinch of Celery will raise hundreds of plants.
Concerning annual flower-seeds, some of the best got-up seedsmen's catalogues afford a good deal of information; and to these I must refer the amateur in the meantime, until I treat of them in a chapter on flower-gardening.