Using soil improvers I’ve got worms!

How do earthworms help plants grow?

Britain has about 16 species of earthworms and at last I am seeing greater evidence of them in my garden. Worm casts – the little heaps of ‘worm poo’ can be a nuisance on immaculate lawns or gravel paths, but they have an important role in improving our soils. Earthworms eat decaying plant material, emerging at night to pull plant debris into their tunnels. This activity aerates the soil, adds to soil fertility and aids drainage. This improvement to soil ecosystems promotes better root growth and healthier plants. There are worms in every soil, some are more specialised and populate our compost heaps. (I don’t know how they get in the ‘hot bin’ though!)

 

The importance of a healthy soil ecosystem

 

Soil is amazing stuff! Ideally rich and dark and full of life. When I first moved into No 9, I discovered that most of my back garden was smothered under an old concrete patio. Gradually I have been reclaiming the ground from sticky, dense clay to a richer loam with the addition of composted bark, garden compost and sowing green manures to improve the soil. You may have poor, sandy soil, hard compacted ground, dry chalky soil or builder’s rubble. Whatever condition it is, it needs a little love.

 

Soil Improvers bring benefits to the soil by:

·       Improving structure.

·       Increasing capacity to hold onto water and nutrients.

·       Providing better drainage.

·       Adding organic matter to aid biological organisms.

The effect is additive, not all are suitable for sustaining plants on their own

1. Home -made compost, making use of waste products from your home and garden. The decomposed nitrogen rich vegetable scraps and peelings add valuable nutrients to enrich the soil. Applying about 6 weeks before planting out will make sure these readily available nutrients are put to best use. The most sustainable..
   
2. Green waste compost may be sold as soil improver at garden centres or free at local authority household waste sites (you need to fill your own bags). Made from our collected green bin and food bin waste which is ‘hot composted’; this typically contains a higher proportion of woody waste which locks in the nutrients (slow release!). 
3. Home-made woodchip from shredding your woody prunings. Don’t use fresh. 
4. Animal manures should be well-rotted before adding to soils. There is the potential for importing weed seeds. Chicken manure is high in nitrogen and should be used sparingly. 
5. Leafmould takes a while to produce but is excellent to use as seed compost or mulch as it lacks weed seeds. Low in nutrients. 
6. Mineralised Straw. The process slows the rate the straw breaks down making it last longer. 
7. Spent Mushroom Compost. Contains chalk, relatively high nutritionally.

Is seed compost necessary?

 

I would say it depends! It depends on what seed you are sowing, the rarity or scarcity, the size, the treatment of the seed (pelleted or not) and the germination of the variety. For example I sowed my chilli pepper seeds in February indoors in a propagator in a proprietary seed compost. I sowed my sweet peas in the autumn last year in garden soil mixed with multipurpose compost. The seed compost is generally finer grained and contains lower nutrients so the emerging seedlings have sufficient to start growing but are not overfed and grow sappy. Multipurpose compost is coarser, being a mixed blend with higher nutrient levels to sustain a longer growing period.

I used to make my own seed compost from leafmould, sand and vermiculite but I no longer have the space to store the bags of leaves for 2 years necessary for them to rot down properly.

 

What are John Innes composts?

 

These soil based formulations were developed in the 1930s at the John Innes Horticultural Institution (now the John Innes Centre) to suit the plants throughout different stages of growth.

·       No. 1. Suitable for seedlings and plug plants and rooting cuttings.

·       No. 2. With higher levels of nutrients this one is for potting on.

·       No.3. Highest in loam and nutrients this one is for mature plants kept in containers

 

The benefits of using John Innes composts are their reliability, possessing good water retention and consistent nutrient levels. They are heavy though when moving filled pots or containers.