Hartley Magazine

All the latest news, hints, tips and advice from our experts

Compost Corner

One of the most important considerations when growing plants is the quality of the medium that you grow them in and that is just as relevant in a greenhouse as outside in the garden. In the greenhouse our plants are either nurtured in pots of compost and/ or grown on in border soil. Generally the pots are cleared out at the end of the season, washed out and then filled with top quality seed and cutting compost to nurture all these greenhouse grown plants.
Greenhouse Gardening
When it comes to the soil in your greenhouse border, just like all other soil and compost that supports plant growth, it can become depleted of plant nutrients and vital essential trace elements essential for healthy plant growth, plus if you continually grow the same crop in the soil year after year, common pest and disease problems can prevail. January is a great time to dig it out completely and add it to your garden compost heap where the cold and the birds will help deal with pest problems. Replace the soil with a quality, loam based compost such as John Innes No 3 which is ideal for mature plants, or if you are using it as a seed bed then use John Innes Seed Compost or John Innes No 1 which has lower levels of nutrients, so it is kinder on delicate plant roots. Remember though, that you will need to feed your plants as they develop.
Potting Bench Supplies
For all your other greenhouse needs you need to choose the right compost for your plants. Don’t cut corners on compost: it really does make all the difference. Remove all of last season’s leftovers to the garden and use it as a soil improver, or for outdoor containers. Visit the garden centre and buy this season’s fresh seed and potting compost from a reputable supplier, look out for seasonal bargains but not if they are last year’s stock and always buy plenty as soon as the new stock arrives, as invariably you will run out just when you need it the most.
Where possible keep compost in the greenhouse or protected from the weather, especially early in the season. Always warm your compost to air temperature in the greenhouse before use, it avoids shocking seeds, seedlings and plants with unnecessary cold and is just another technique to keep your greenhouse plants happy and healthy.
Pots containing compost from previously grown annuals and tender plants can be emptied onto the garden compost heap, which brings us to one of the confusing things about gardening: garden compost and plant compost.
Garden Compost
A compost heap is where gardeners and garden owners recycle kitchen peelings and garden waste into a rich, crumbly soil improver called ‘garden compost’ or sometimes just compost. Home composting is a vital part of a healthy garden. It enables you to recycle vast amounts of waste that would otherwise end up as landfill and it creates a sustainable supply of rich, organic matter that can be used to enrich your garden soil.
Garden Compost can be mixed with loam and other vital ingredients to make a homemade potting compost for plants, but is likely to harbour rich levels of microbes, including some that may be detrimental to seed growth. It is NOT the same as the compost that you buy in bags at the garden centre. Knowing when to use garden compost (home made compost) and when to choose dedicated plant compost, is just one of the secrets to a successful, healthy garden and greenhouse.
Plant Compost
This is what you buy in plastic sacks from the garden centre and you really do get what you pay for. Each pack is a finely tuned mixture that has been prepared to enable gardeners to provide the very best growing conditions for garden plants. It introduces exactly the right environment to the immediate area around the plant roots to ensure that they have everything they need for successful growth. And because it is sterilised it is also free from weeds, weed seeds and other potential garden problems.
Dedicated Plant Compost is available in a wide range of formulations to provide the gardener with a finely tuned compost for growing and nurturing specific types of plants by catering for their particular growing needs. While multi purpose compost suits the needs of most gardeners, experienced gardeners and greenhouse gardeners tend to have and to use a number of different formulations to suit their plants and their needs.