Materials for Use as Garden Fertilisers
Shoddy — the waste materials from wool factories — can be bought under brand names in J- or l-cwt. Bags. It contains up to 14 per cent of nitrogen and should remain active for at least three years. Apply at the rate of £ to 1 lb. per sq. yd. In the autumn or winter.
Sawdust, when properly handled, builds up the humus content in the, but before being mixed in should always be composted. Never use fresh, un-decomposed sawdust, because it robs the soil of nitrogen. To obtain the best results mix three parts by bulk of sawdust with one part bulk of well-rotted F.Y.M. or poultry manure, and leave it in a heap for 12 months. Nitro-chalk may be added to speed up rotting at the rate of l lb. per 20 lb. sawdust. Leave the whole heap moist. Sawdust is riot a fertilizer, on account of its very low nutrient content. The usual rate of application is 10 to 15 lb. per sq. yd.
Although old sawdust looks unattractive, it is ideal for mulching fruit bushes, shrubs, or other widely spaced plants. It eventually breaks down into humus when dug in at the end of the season.
Leaf mould or leaf soil taken from the top few inches of woodland soils makes good humus, particularly when it is derived from oak and beech trees. The leaves of these trees are more likely to be acid than those of other trees. Compost fallen leaves in heaps and then sandwich them in 6-in. layers between thick layers of soil. If placed in shallow heaps not more than 2 to 3 ft. high, a fibrous mould will result after about a year. Apply this mould at the rate of 5 to 6 lb. per sq. yd. A better product will result if National Growmore Fertilizer is sprinkled on the heap during the process of building.
For those who live in coastal districts seaweed is a cheap, excellent manure. Spread at the rate of 10 to 12 lb. per sq. yd. and dig in immediately. It will then provide nearly as much nitrogen and up to three times as much potash as an equivalent dressing of farmyard manure. Seaweed breaks down rapidly into humus, and is free from weed seeds and disease organisms.
Dried seaweed meal is a good substitute for bulky manures and is suitable for a wide range of crops when used at the rate of 4 to 8 oz. per sq. yd. Best results will follow if the dried seaweed is worked into the soil in the autumn for crops that are to be planted in the spring.
When preparing the ground for sowing or planting, or making soilfor pot plants, three things should be done. First make sure that a material sufficiently humus-forming to keep the soil in good condition has been applied; secondly, correct any sourness by liming, and thirdly, ensure that there is a good supply of nitrogen, phosphates and potash. These nutrients can be provided by making separate applications of, say, sulphate of ammonia for nitrogen, superphosphate for phosphates, and sulphate of potash for potash. Alternatively, mix these three fertilizers together and spread in one application. This is more convenient and generally gives a more even distribution of the nutrients. But a ready-mixed compound fertilizer can be bought. Many manufacturers have their own proprietary brands which are listed for use for various plants. The best are made from the fertilizers already described. Those that include ammonium phosphates are .more concentrated than those based on ‘super’ phosphates.
The chemical analysis of a compound fertilizer should always be shown on the container thus, 5-5-10. The first figure denotes the percentage of nitrogen, the second figure the percentage of soluble phosphoric acid and the third figure the percentage of potash. If one of the three major elements is lacking in a fertilizer a zero appears in its place; thus 5-0-10 means 5 per cent nitrogen, no soluble phosphoric acid and 10 per cent potash.
THAT TO BUY
When selecting compound fertilizers take note of the ratio of N, P and K as well as the actual percentage of each. Fertilizer ratio is the analysis reduced to its simplest terms. For example the 5-5-10 fertilizer has a ratio of l :l :2. A general fertilizer for outdoor vegetable crops should have a ratio of approximately equal amounts of N, P and K, that is a ratio of 1 :l :1, whereas a fertilizer for root-bound plants in pots should be a high nitrogen liquid feed such as the John Innes liquid which has an analysis of 18-65 per cent N, 6-2 per cent P206, 6-2 per cent K20, or a 3:1:1 ratio.
NATIONAL GROWMORE FERTILIZER
(7 per cent N, 7 per cent P2O5, 7 per cent K20) There are 100 or so compound fertilizers available. A good general, all-purpose-compound fertilizer is the National Growmore Fertilizer which will probably meet the needs of most outdoor crops, irrespective of their precise requirements.
JOHN INNES BASE FERTILIZER
(5-1 per cent N, 7-2 per cent P2Os, 9-7 per cent K20) The John Innes Base Fertilizer used at the rate of 4 oz. per sq. yd., or at 4 oz. per bushel of potting compost, will certainly supply the needs of most pot plants as well as greenhouse crops in their early stages of growth. It will carry these crops through until quick-acting nitrogenous top dressings become necessary. Once specialization in the growing of particular plants such asor roses is started, a more serious study of the fertilizer programme can be made.