By Dave Brice (President HwDAA)
POWDER FERTILISERS sold loose
In both Alderman Moores and Bower Ashton Stores, we sell powder fertilizers, the use of which, I think, has been lost with the passage of time. It’s much cheaper than buying packaged fertilisers and does the same job – check the nutrients listed on packets to see what they contain.
Fertilizers contain concentrated sources of the nutrients that plants need to produce strong root systems, healthy leaf growth and abundant flowers and fruit. They’re generally used from March to early September. In my experience, well-fed vegetables will produce bigger crops with more flavour, and fruit trees and bushes will retain more fruit for harvest. If you apply the right fertilizer at the right time of year at the right rate, you will encourage optimum growth. Too little will give poor results. Too much will scorch plants and interfere with the take up of other nutrients.
However nothing will produce quality crops without attention to (a) soil condition / structure (making sure the soil particles are the appropriate size for the roots to penetrate– eg a fine tilth for seeds – and that it contains plenty of organic matter) and (b) removing weeds and thinning plants to reduce competition for nutrients.
There are other methods of managing the delivery of nutrients to plants, (eg adding lots of manure to defined no dig beds) but the difference is that you do not know the precise nutrient content in the same way, and they tend to be long-term additives so you can’t give a quick boost when the crops need it. Because we are using the soil intensively on allotments and removing produce and plants, we need to put back what is taken out, one way or another, in order to maintain the fertility of the soil.
About Fertilizers.
The three main nutrients contained in fertilizers are Nitrogen (N), Phosphorus (P) and Potassium (K). The nutrient content is expressed in numbers (eg 7-7-7 for Growmore) which indicates the percentage weight of each component in the fertilizer - in the order NPK - the balance is made up of a carrier material which helps spread the fertiiliser.
Nitrogen (N) is used by plants in large quantities and fuels the growth of leaves and shoots. It is absorbed through the soil water and is easily leached out of the soil eg during winter rains. N deficiency is recognized by the yellowing of older leaves, and slowing or stopping of growth and flowering. Leaves may drop sooner than expected. Excess N is recognized by extremely fast lush growth, resulting in long, spindly, weak shoots with dark green leaves.
Phosphorus (P) is important in the growth of roots, the ripening of fruit and cell division. It is used most heavily during blooming and seed set, and by quick growing plants harvested young. Phosphorus is unavailable to plants when the pH is slightly unbalanced (best absorption is when the soil pH is between 6 and 7 – slightly acidic to neutral). It is released in soil through decomposing organic matter and deficiencies are rare. Phosphorus deficiency is recognized by dull blue/green leaves and purplish stems, and short and thin shoots. Plant maturity, flowers and fruit are delayed and small.
Potassium (K), sometimes known as potash, is essential for good flower and fruit formation and it increases the general hardiness of the plant and its resistance to disease, pests and frost. Potassium deficiency is hard to recognize, but plants are generally sickly, with poor quality fruit and seeds, stunted weak growth and a scorched look to the edges of older leaves gradually progressing inwards. Too much K leads to magnesium deficiency!
Magnesium (Mg) is another nutrient needed by plants for photosynthesis, chlorophyll and movement of other nutrients around the plant. Deficiency is fairly rare, especially where lots of farmyard manure is applied, but the symptoms are yellowing between leaf veins, leaf tips curl upwards and early leaf fall.
Application
You can add the fertiliser to the soil either as a base dressing (dug into the soil before planting), a top dressing (applied to the surface of the soil), a liquid (dissolved in water and applied to the soil surface – which gives a faster reaction than a top dressing), or foliar feed (dissolved in water and sprayed on the leaves). An average handful of the fertilizers listed below is about 40-50 gms.
Organic Fertilizers
Hoof & Horn. (13/14-0-0)
This organic fertilizer is a slow release supply of nitrogen for plants that produce large amounts of leaf. Examples include brassicas such as cabbage and kale, as well as lettuce, courgettes, rhubarb and corn. Use as base or top dressing at 150gms per square metre at start of season and 25gms per square metre when transplanting.
Bone Meal. (3-20-0)
Despite its smell, this slow release organic product which promotes strong root growth is useful when planting fruit bushes and trees and as a base dressing for vegetables, especially Beans and Peas. Do not use on acid loving plants i.e. Blueberries. Use 100gms per square metre every one or two years.
Fish Blood & Bone (3-8-0)
This organic fertilizer is widely used as a base or top dressing on flowers and vegetables and is excellent when a long term feed for leaf and root growth is required. Use 125gms per square metre dug in early season and 50gms per square metre as a top dressing, shake off any lying on foliage.
Non Organic Fertilizers
Sulphate of Ammonia. (21-0-0)
This soluble fertilizer (adding N) is used from March to August at 4 to 6 week intervals. Use about 35gms to one square metre as base dressing, top dressing or liquid feed. Effects are noticeable in about 10 days. Can also be used as a compost activator.
Superphosphate (0-18-0)
This is probably one of the oldest inorganic fertilizers. It is best dug in to the root area so the P can be easily found by the developing roots but can also be applied as a top dressing. Use in early winter for root crops 100gms per square metre.
Sulphate of Potash. (0-0-50)
A very fast acting and soluble fertilizer (adding K). Use at 45gms per square metre as a base dressing before sowing. During the growing season use at 15-30gms per square metre as a base dressing or liquid feed. For fruit trees apply at double the rate. Do not apply in heap at base of stem, and shake off any lying on foliage.
Magnesium Sulphate Better known as Epsons Salts
this product corrects Mg deficiencies (which are rare). Soluble in water and mainly used in foliar and liquid feeds at 20g per litre of water. It’s used in a wide range of crops, especially glasshouse crops like tomatoes.
Growmore (7-7-7)
Probably the most well known all-purpose fertilizer, it’s a mineral based regular sized fertilizer for easy spread and can be used for all types of flowers and vegetables during spring and summer. Use 125gms per square metre dug in early season and 50gms per square metre as a top dressing.
Garden Lime
Plants perform best in a soil pH of about 6.5 (very slightly acidic). Soil tends to get more acidic over time, so lime is used to reduce the acidity and return the pH levels to 6.5. Old gardeners says it “sweetens the Soil”. Check your pH before liming. Don’t lime and manure the same bit of ground in the same year, as the effects counteract each other.
