choose the best compost for garden healthy plants
CHOOSE THE BEST COMPOST, There’s a bewildering array of seed sowing, potting and other composts available. Geoff Hodge explains the differences between them
Bagged compost might look and feel pretty similar to the material we make in our compost heaps – so why pay for it, when you can make it yourself? The truth is, seed sowing, potting and other types of bagged growing media are far superior to the homemade stuff. Though ‘garden compost’ is great for improving the soil or using as a mulch, it generally won’t perform well enough to use in pots. Teams of scientists work diligently on the creation of the perfect seed sowing or potting compost, bringing together the optimum ingredients, working out the ideal proportions in which they should be mixed and assessing performance.
Compost is subjected to thorough, stringent testing before being brought to market and is scientifically formulated to provide the exact growing conditions that plants need to perform to perfection.
The Best Compost Informed decision
When confronted by pallet after pallet of heavy, bagged composts at the garden center or DIY store, it’s tempting to simply buy on price. But to make a more informed decision, shop at a good garden center that arranges products by type and offers point-of-sale information. Read the ingredients on the bag and make a note of the brands you’re using. Experiment with a couple of different brands to see which
products you get on with. It’s only by experimenting that you can discover how each compost ‘works’ – how quickly it dries out, how much water to give, how much fertilizer to add and how often. Compost that has been sitting around for several months may have become ‘sour’ due to the buildup of excess nutrients. To ensure you’re buying fresh, watch out for bags that have faded in the sun, or that are saturated with water or exposed to the elements. Good garden centers keep their compost under cover to prevent this happening. Always buy fresh compost each year. If old compost goes off, it can affect seeds, seedlings and young plants.
the major constituents of composts are materials with Three main properties: they Hold moisture and air: they provide drainage to prevent waterlogging: and they create a stable structure that doesn’t break down or become compacted
➤ 1 PEAT
Apart from loam-based John Innes composts, peat has always been the main constituent, but it’s being phased out by 2020. Advances are being on improving p substitutes
➤ 2 PEAT REPLACEMENTS
these include wood fiber and composted bark, coir (coconut fiber) and local authority green waste they might include materials to help improve drainage and keep the compost open, such as grit, sharp sand, rock wool, vermiculite and perlite
➤ 3 LIME
Most bagged composts (except ericaceous) contain lime or similar to help increase compost pH to around neutral (pH7).
➤ 4 FERTILISER
Nutrients in the form of a standard fertilizer maintain good growth for ﬁve to six weeks. After that, you’ll need to add supplementary food. Products containing a slow- or controlled-release fertilizer can feed for up to six months.
➤ 5 WETTING AGENT
Once peat dries out it’s hard to re-wet, so the compost might contain a wetting agent for easier watering.