“Compost” is the word used generally for ‘decomposed organic matter’. added to soil to improve it for growing plants. It’s rich in nutrients and beneficial organisms because it is made by breaking down organic materials such as plants, leaves, shredded twigs or garden scraps.
It can be hard to know which compost to choose as there are so many types available but don’t worry, that means there’s one just right for the job!
Why do I need compost?
Some garden soils can be good for growing plants, however they can vary considerably (even within the same garden) and very few gardeners are lucky enough to have perfect soil. Adding compost or soil improver helps to provide the right growing conditions, which will ensure you achieve bigger and healthier results.
Choosing the right compost is the way to get the best out of your plants/fruit/vegetables but the ingredients for composts can vary dramatically. For optimal results it is wise to use a ‘fit for purpose’ compost which has been tailor-made for the job in hand.
The do’s and don’ts of compost
- Do choose a specialist compost for the task in hand. This will ensure you create optimum growing conditions.
- Do check out your garden soil pH balance before you get planting as, depending on the results, you may need to mix in Lime soil improver to get you started.
- Do use any leftover compost by digging it into your existing soil around your garden as a soil improver.
- Do use fresh compost each year to pot up your existing and new plants as this minimises risk of pests and diseases being carried over. It will also provide fresh nutrients to replace those that have been used up.
- Always water in your plants (even if the ground is moist) to remove air pockets and ensure the roots are in contact with the soil.
- Do use gloves when gardening.
- Don’t sow seeds in standard compost. For best results use a specialist seed compost that provides for optimum root growth and contains plant food to help them develop.
- Don’t be put off growing fruit and vegetables by lack of space. You can achieve healthy crops in pots, hanging baskets and grow bags; even in the smallest of areas.
- Don’t forget that some acid loving plants such as azalea, camellia or rhododendron will require an ericaceous compost with a lower pH.
- Don’t assume that there are enough nutrients in your garden soil to use for potting up containers and baskets. Garden soil may contain unwanted weeds, pests and diseases and may hold water differently so your plants may suffer.
- Don’t forget that decorative barks don’t just look great on beds and borders, they suppress weeds and help retain valuable moisture too.
- Don’t forget to follow the compost label instructions.
Different types of compost
Broadly speaking, there are five different types of compost:
1. Peat based compost
There are many formulations of peat based composts available to the gardener. These are made from a base of peat blended with other ingredients such as fertiliser, sand and/or grit, vermiculite or perlite, wetting agents and lime. The exact formulation will depend on the intended use of the compost.
2. Loam based compost
John Innes Composts are soil-based made from a mixture of loam, sand or grit and peat with increasing amounts of plant foods added.
- Levington John Innes Seed Compost: Contains the smallest amount of nutrients as this encourages the best germination and growth of tiny roots and shoots.
- Levington John Innes No.1 Compost: Contains slightly more nutrients and is for transplanting seedlings.
- Levington John Innes No.2 Compost: For when you are potting up small plant.
- Levington John Innes No.3 Compost: Has the most nutrients, as this is designed for final planting up of plants ready for display or cropping.
3. Peat free compost
Peat free compost can be made from several different base ingredients, such as: wood fibre, composted bark, coir, and green compost.
Specialist composts are then produced using one of the above as a base, to which other ingredients are added depending on what they are to be used for. These come under the following headings which also have an explanation of what they consist of and where they are used.
4. Organic compost
Organic composts contain a mixture of materials in varying proportions, such as peat, expanded wood fibres and composted bark. They are enriched with naturally occurring nutrients and derived from plants and animals. Organic matters feed plants for differing periods and, depending on the organic compost purchased, some feed for up to 3 months. In addition the composts may be certified as organic by organisations such as the Organic Farmers and Growers Association.
5. All/multi purpose compost
This is a compost that can be used around your garden in beds, borders, pots, containers or hanging baskets. It comes in different blends of ingredients. For example some contain varying plant foods that will feed your plants anywhere from 6 weeks up to 6 months. Others can limit the amount of watering you need to do by absorbing water then storing and releasing it as the plant requires.
- Miracle-Gro All Purpose Enriched Compost: Enriched with Miracle-Gro Plant Food, this premium low peat compost is guaranteed to grow plants twice as big (versus ordinary garden soil). It also contains Smart Release Feed granules that allows season long feed.
- Miracle-Gro Peat Free All Purpose Enriched Compost: Produced using a unique and revolutionary Fibresmart Technology - the hollow wood fibres are 100% natural and peat free. They ensure the optimum balance of air and water for strong roots to grow healthy and beautiful plants. Also includes smart release granules giving the plant a season long feed.
- Levington Multi Purpose Compost: Its superior texture helps plants all around the garden, develop stronger roots and healthy growth. Has a low peat formula and absorbs 25% more water than ordinary multi-purpose compost.
- Levington Multi Purpose Compost with added John Innes: Based on Levington® Multi Purpose Compost, with added John Innes (sterilised loam, peat and grit). Used by many professional and traditional gardeners. Provides extra weight in pots for top-heavy plants.
- Most plants you buy from garden centres are already planted in suitable compost so, to encourage the roots to grow out and into the ground, try and match these conditions when you plant. This means enriching the planting hole with a good all purpose compost. If your plant is pot bound, you can tease out the roots to help them root into it.
- Autumn is the best time to plant out all permanent bed and border plants, giving the roots time to establish before winter sets in.
- When container planting, make sure the container has good drainage holes. You can add a layer of stones, gravel or crocks (broken plant pots) to provide a good drainage layer
- Acid loving plants such as rhododendrons, azaleas and camellias, must be planted in a specialist ericaceous compost.
- You’ll need to give your plants an additional boost once the plant food in your compost has been used. For fantastic results make sure you feed them regularly with products such as Miracle-Gro All Purpose Plant Food.
- If you don’t use all of the compost bag, make sure you store it somewhere dry and roll the top over to keep it moist.
- Compost should be used within a year, as after this time the nutrients and any added feed will lose performance.
Bark can provide a clean visual background that makes plants and flowers stand out. However, applying a layer of organic material such as bark (known as mulching) does more than make your garden look attractive. It also helps to retain soil moisture, suppress weed growth and will gradually improve the structure of your soil.
You can get other types of mulch such as pebbles, sea shells, slate, cocoa shells and coloured wood chips.
- Levington Water Saving Decorative Bark: This bark is designed to reduce moisture loss and suppress weeds. Made entirely from natural bi-products.
- Levington Decorative Chipped Forest Bark: These large chips of bark suppress weeds and aid moisture retention in the garden. Long lasting and produced from renewable sources.
Top tips for bark mulching
- The best time to lay down a layer of bark or mulch is when the soil is thoroughly soaked through, warm and free from weeds. Generally this is in early autumn or spring.
- You should put down a layer that is at least 5cm thick as this will help prevent water evaporation.
- There are different bark and mulch products available so you can choose the one you prefer the look of. They come in all different colours and sizes, so take your pick.
This compost has a more open texture which helps root growth and has little nutrient content, as bulbs themselves don’t really need them to develop until flowering stage. Bulb compost normally has ingredients such as charcoal or oyster shells in it, which keeps the compost fresh.
Top tips when using bulb compost
- Put a thin layer of gravel on the top of the pot as this will help with moisture retention and stop weeds from growing.
These are great if you are limited on growing areas in your garden. They take up very little space and can be placed just about anywhere. You can grow all sorts of wonderful fruit, veg and herbs. Including salad leaves, Tomatoes, Carrots, Potatoes, Onions, Strawberries and Cranberries. Most Grow sacs will have a plant food mixed in that will feed for up to 8 weeks and after this time you would then need to feed regularly. You can also get peat free and special water absorption ingredients mixed in.
- Levington Tomorite® Giant Planter with Seaweed: A bigger bag for better growth. Designed to absorb and store more water, meaning you don’t have to water it so often. Enriched with both Tomorite® Plant Food and Seaweed, you can expect a delicious top quality crop of full flavoured tomatoes.
- Levington Original Gro-Bag: Perfect for vegetable crops. Ideal for growing tasty tomatoes, peppers, aubergines, cucumbers, green beans and melons.
- Miracle-Gro® Performance Organics Peat Free Fruit & Veg Planter: A natural and organic peat-free compost ideal to fit 2 plants. Perfect for growing your own produce such as fruits and vegetables. Glorious on plants, gentle on nature!
Top tips for using grow sacks/planters
- Don’t let a lack of outside space put you off growing your own. You can produce an abundance of crops in small pots, containers and window boxes which will fit nicely onto the smallest of outside spaces.
- If you have children or grandchildren then get them involved! They can help you sow the seeds, care for them, harvest, cook and enjoy eating the delights of their labours.
- Do check your watering regularly and check bags/planters before watering as bags of compost hold water differently to pots.
This compost is best for starting plants off. Either seedlings that you have grown and are at the next stage, or young plants you have brought. Most potting composts will have added extras that your young plants need to help them develop into strong healthy mature plants.
- Levington Seed & Cutting Compost: For sowing seeds, striking cuttings, delicate seedlings. Unique balance of nutrients for stronger, healthier plants. Specially formulated with high-phosphate content for optimum root growth.
- Miracle-Gro Moisture Control Enriched Compost Pots & Baskets: Perfect for hanging baskets, patio pots and houseplants. Exclusive Aquacoir formula stores and releases water when plants need it. Absorbs twice as much water as ordinary multi purpose compost and feeds for up to 6 months.
Top tips for using potting compost
- Make sure you only pot up one size at a time. This means each time you do your plants will get fresh compost which contains fresh nutrients and a good boost. If you put a small plant in a huge pot the benefits of the compost will be lost over time before the plant can use them.
- To prevent roots from growing out the bottom of your pots you can raise them 1-2cm off the bench, this will also allow air to pass under the pot
Seeds and young plants
Young seedlings are very sensitive to their environment and need different nutrients and care than more mature plants. Normal potting composts are too rich for seedlings and have a texture that is too coarse for fine seedling roots to penetrate. Specialist seedling composts have lower nutrient levels but higher phosphate, which helps to develop a strong root structure. It also has a finer texture to create the perfect surroundings for the young plants to flourish.
- Levington John Innes Seed Compost: Ideal for maximum root growth of seedlings and root cuttings. Contains a traditional mixture of loam, peat and sand. The use of sand increases drainage in the compost which helps the development of seedlings. Produced with the specially balanced nutrient levels.
- Levington Seed & Cutting Compost: Specially formulated with high-phosphate content for optimum root growth. Ideal for anything small and sensitive such as seeds, striking cuttings, delicate seedlings and all sensitive young plants.
- Levington John Innes No.1: With a specially balanced nutrient mix ideally matched to the needs of developing seedlings, young plants, and newly rooted cuttings, this compost features a traditional mix of loam, peat and grit.
Top tips for using seed compost
- Many plants can be grown from seed but their requirements are all different. Make sure you check the care instructions before planting and follow them closely.
- Avoid feeding your seedlings until they are established to avoid damaging them or causing a surge in growth too soon.
- When buying seeds, look out for varieties marked ‘F1 Hybrid’. These have been specially bred to produce more vigorous growth and beautiful blooms.
These are used to improve aeration and drainage in heavy clay soils and add body to light sandy soil to help retain moisture and nutrients. It also boosts the soil fertility by adding nutrients to encourage healthy foliage, flowers and root growth.
Top tips for using soil conditioners
- If you’re planning to plant directly into your garden soil, add a soil improver to enhance growing conditions.
- It’s unlikely that you will be lucky enough to have naturally great soil, so dig through a product such as Levington Organic Blend Soil Conditioner to greatly improve your results.
- Don’t get rid of any worms that are in the soil when digging in, as worms help with aeration and drainage.
There are a multitude of specialist composts for plants with special tastes. Roses, Ericaceous, Cactus and Bonsai’s are some which have specific requirements from the soil they are grown in. Each dedicated compost will contain what that specific plant needs and if you try and grow these in the wrong soil environment then they may produce poor growth
- Levington John Innes Ericaceous Compost: Specially formulated for growing acid-loving or lime hating plants. Feeding your plants for up to 6 weeks.
- Levington Rose, Tree & Shrub Compost: This compost enables the fast establishment of roses, trees and shrubs. Packed with a special combination of nutrients and water retaining agents.
- Levington Ericaceous Compost: With a high iron formula for greener, healthier leaves, this product is perfect for growing acid-loving or lime hating plants.
Top tips for finding your specialist compost
- When buying plants, check the care label to see what type of conditions they prefer. If they are acid-loving you’ll need to make sure you have the right compost, feed, etc
- Check the acid/alkaline balance of your soil with a simple pH Test Kit (available from all good garden centres). Then you will know what plants like your beds and what may do better in pots.
Can I re-use my patio pots year after year?
You can certainly re-use them but it’s best to tip out all of the old compost and then wash the containers thoroughly with warm soapy water, followed by a good rinse with a solution of cold water and a garden detergent. It’s important to do this because your existing compost may be harbouring vine weevil larvae or other garden nasties. It’s far better therefore to have a spring clean and thus minimise the risk of pests and diseases infesting or infecting your new displays.
Why can’t I use my own garden soil to pot up plants?
Garden soil doesn’t hold as much water and can lack essential nutrients, so plant growth will be slower and watering can be difficult. Garden soil will often also harbour pests and diseases.
I’ve opened up my compost and it looks like an insect has laid eggs in it
This is most likely to be the small round coloured granules of controlled release fertiliser, that when squeezed will pop open releasing a liquid which is the fertiliser concentrate. These little granule cases have a semi permeable membrane which allows water to soak into them to dissolve the feed inside them. The nutrients are then released back into the compost in a soluble form for the plants to absorb. The cases will naturally breakdown in the compost over time.
How can I find out whether my soil is suitable for rhododendrons?
The best way is to use a soil pH testing kit. If the results show your soil is naturally acidic then rhododendrons, azaleas, camellia and the like will thrive. If it’s neutral then you can still plant, but do feed with a special plant food that’s been formulated for acid-loving plants such as Miracle-Gro Water Soluble Ericaceous Plant Food. If you’ve got alkaline soil then your best bet is to plant the rhododendrons in a container filled with a suitable ericaceous compost. Try Miracle-Gro Azalea, Camellia & Rhododendron Enriched Compost and then feed with an ericaceous plant food throughout the Summer.
Can you explain the differences between the John Innes composts?
John Innes Composts are soil-based growing media made from a mixture of loam, sand or grit and peat with increasing amounts of plant foods added. Levington John Innes Seed Compost contains the smallest amount of nutrients as this encourages the best germination and growth of tiny roots and shoots. Levington John Innes No.1 Compost has slightly more nutrients and is for transplanting seedlings. Levington John Innes No.2 Compost for when you are potting up small plants and Levington John Innes No.3 Compost has the most nutrients, as this is designed for final planting up of plants ready for display or cropping.