Fertiliser Buying Guide
Plants 
need an abundance of different elements to grow to their full potential and remain healthy. While some of these things are supplied in the environment already--like oxygen, hydrogen and carbon--others often need to added and replenished by us. Use this guide to help you pick the best fertiliser for your garden , whether it's full of roses, courgettes or unruly weeds.
Fertiliser Types
- Granular : These are applied dry and must be watered in. If your a beginner gardener, granular fertiliser may be the best option, since you can better see how much you are using and where exactly it is being spread.
- Quick-release fertiliser typically lasts for three to four weeks.
- Slow-release fertilisercomes either as sulphur coated, which lasts for about 8 weeks, or polymer coated, which lasts about 12 weeks.
- Liquid fertilisers are faster-acting and require application every 2-3 weeks. These are a little more complicated to use, since you have to mix them with water first and then spray them using a mechanical sprayer or watering can.
Understanding the Label
Your fertiliser's no good if you don't understand the fine print. You could wind up with a formula better suited for watermelons than cherries!
- The three numbers--more commonly referred to NPK on the back of the bag--tell you the percentage of the primary nutrients. The three main nutrients you will most often see are:
- Nitrogen (N) for leaf development and vivid green colour.
- Phosphorous (P) for root growth.
- Potassium (K) sometimes called potash, for root development and disease resistance.
Look a the picture to the left. This bag is marked "16-4-8", as it contains 16 percent nitrogen, 4 percent phosphorous and 8 percent potassium.
For Lawns and Weeds
- Depending on the season and the specific type of grass you're growing, the fertiliser you use can have various percentages of N, P, and K. Fertilizer with pesticides are also popular, so read the labels to make sure you're getting the best combination for your yard.
- Weed and Feed is a common term which refers to fertiliser that contains weed killer. To find out what weeds it treats--like pesky dandelions or crabgrass--Look on the label for a list of weeds that can be treated. The two types are:
- Pre-emergents are weed killers that need to be applied before the weeds germinate. Pre-emergent weed killers are often mixed with fertilizer and are applied early in the season.
- Post-emergents kill on contact, but will not be effective on weeds that have not yet germinated.
Organic Alternatives
- Compost — made from recycled waste, this is one of the best garden materials for soil improvement.
- Fish emulsion — a fish processing by-product that's mild and non-toxic. It's best used on sensitive plants that may suffer from fertiliser burn.
- Manure — help condition the soil. There are "hot" manures such as horse, pig and poultry, and "cold" manures like cow, sheep or rabbit which can be added directly to the soil without fear of plant burn.
- Green sand — contains potassium and iron.
Fertiliser Safety
- Make sure that the excess soil and fertiliser from your garden area has somewhere to go--it has the potential to soak into the ground and affect the water table, or run off into nearby water sources like streams.
- Always follow the directions on the package regarding application procedures and proper attire.
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