Make good use of your
organic gardening compost

You probably find, like many gardeners, that reliance on home-made organic gardening compost nearly always leaves you short. So on this page I cover not only where and how to use it, but how to distribute it more effectively.


Compost quality varies with method and materials used. The holistic approach of organic gardening doesn't distinguish individual nutrients, but on this page I distinguish 2 types of compost:
‘fast/green’ made to heat up, with reduced viable weed seeds and nitrogen draining from excess greens;
‘slow/brown’ formed in cooler conditions, with worm casts to increase phosphate availability, probably more amenable to disease inhibiting microbes.

Prioritizing distribution:
First, consider the condition of your soil and those areas that are in greatest need of improvement. If you garden on poor soil, improving this may take priority.

Plan to rotate compost distribution between needs. Any area that gets none in one season can be a higher priority in the next. Also rotate garden compost with other sources of organic matter like farmyard manure, spent mushroom compost, and turning in green manures. Some of these alternatives cost a little more but they can add to the richness of your home made compost in future years.

For vegetables:
All other factors being equal, I consider vegetables to be the most important application for your organic gardening compost. That’s because they are pretty hungry plants like cabbage etc… that produce high yields of green matter. Most grow complete new root systems and leaves annually from transplants. Also, as the soil in the vegetable plot is usually worked more than other garden areas the organic gardening compost applied here decomposes quicker.

I suggest applying the ‘fast/green’ compost to ground for leafy vegetables like cabbage, lettuce, celery, chard, rhubarb etc… You can economize by restricting it to planting pockets; do mix it intimately with the soil fill. But if the surrounding soil is poor you will need to improve the whole bed, otherwise roots may not spread out. Side dressings of compost can be laid down in addition where necessary.

For improving the vegetable bed generally, work a 2 inch layer into the top 4 inches of soil. This can be done in time with crop rotation before a crop such as beans.
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For Runner Beans I prefer ‘slow/brown’ compost. The high humus content helps moisture retention. Available phosphates aid root development. Potassium stimulates flowers and fruit. (In fact runner beans are not vegetables but fruit).

For tomatoes make a 50:50 mix of ‘slow/brown’ organic gardening compost and soil. The inclusion of comfrey leaves is beneficial here and especially ongoing liquid feeds of comfrey.

Going further with liquid compost:
Your organic gardening compost goes a lot further as fertilizer when liquid feed is made from it. To do this suspend a bag full of ‘fast/green’ compost in a barrel of water for a few days. It can be used to liquid feed vegetables, tomatoes, cucumbers and greenhouse plants, as well as flowers.

For flowers:
The next priority is annual flowers as they grow completely anew and the soil is more disturbed. Next comes the herbaceous perennial flowers. Give special attention to any vigorous herbaceous plants or climbers that put on a lot of growth in one season.
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The ‘slow/brown’ compost is preferable for flowers, root development and moisture retention, over ‘fast/green’ stuff with abundant nitrogen content. But small newly planted flowers can be given a boost with the liquid feed described above. With herbaceous perennials compost can be restricted to mixing in with soil 50:50 when transplanting or dividing.

For seed compost:
Leaf mold is the first choice as a base for seed compost. Alternatively use the finest most mature ‘slow/brown’ garden compost. These may contain more weed seeds (clean by ‘stale bed’) but reports indicate that seedling disease inhibiting microbes are probably present in both these composts. See making compost.

For making new lawns and planting:
Laying turf or seeding a new lawn should take a high priority for your available organic gardening compost. Mix a 3 inch layer into the top 4-6 inches. Use the ‘fast/green’ compost; this contains fewer viable weed seeds.
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For fruit:
Most fruit don’t put on masses of growth annually; but some have widespread root systems. Above all fruit need to be kept moist, and high potassium low nitrogen content is preferable. So I prefer the ‘slow/brown’ compost; the rougher less developed material is acceptable for making water retentive humus. Blackberries need plenty. Use a top dressing of comfrey leaves underneath the compost. Liquid compost feeds before flower set are also good.

For shrubs, hedging and trees:
Shrubs and trees come at the bottom of my list because in general the rate of growth appears to be slower. Also shrubs and trees usually have widespread root systems that take in a large volume of soil. They often muscle in on the flower bed or lawn.

Within this category hedging plants have the highest priority because they are closely planted, and usually cut each year to encourage growth. Slow evergreens are less important than deciduous. Mix into back fill soil 50:50 when planting or transplanting. Be aware that if you make a planting hole in poor soil and fill it with compost the plant roots may not venture beyond the hole.

For some trees, root associations with particular fungi are a far more important source of nutrients than fertilizer. You can carefully mix a 1 inch layer of compost into the top 2 inches or simply top dress surface feeding roots. With trees you can mix compost into holes or trenches and try root pruning.
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For small lawns:
Lawns on poor dry sandy soils, silt, chalky soils, or shallow soils, can be improved by top dressing with your organic gardening compost. It can be used on other lawns too, but mixtures of loam, sharp sand and peat/coir/compost are more widely recommended. On clay soils use a mix of compost and sharp sand. For perking up lawns generally, measured amounts of organic fertilizer can be used instead.

Top dressing is commonly done on fine lawns. It is often used to even out hollows, but for this you really need loam not organic gardening compost. Restricting it to part of the lawn may lead to uneven lawn quality. For lawns over loam, organic matter and nutrients are well conserved by leaving the grass cuttings in place during the summer. This alone may perk up the lawn. Compost may help to break down thatch but always rake thatch out first.

Use fine and fully matured compost to top dress lawns. The job is done mainly in autumn but alternatively in spring. Brush in top dressing to no more than 1cm about 1/3 inch deep. Most grass blades will peek through. At this depth 1 cubic foot will cover 4 square yards and 1 cubic meter will cover 100 square meters.

In loamy soils mix the soil cores from hollow tine aeration into your organic gardening compost. (Compaction is no less reduced.) Top dressing lawns with garden compost need only be done every 2 to 3 years once the initial soil improvement is complete.
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For sorting and sifting:
Mature organic gardening compost can be distributed to soil and plants without worry. But immature stuff containing bits of un-decomposed material should not be dug in. It robs nitrogen from the soil as bacteria use nitrogen to complete the decomposition.

You could save running short by adding a nitrogen containing supplement like manure, comfrey liquid, or urea, and then incorporate it. I usually add the supplemented material back to the heap to finish the job properly.

If you need small amounts of gardening compost and only have the immature product then you could sieve the bits out, use the fines, and return the debris to the heap.

For mulch:
Unfinished compost of highly fibrous woody material makes a good mulch for shrubs and trees. It has a slow decomposition rate and remains in place longer. Its hard discrete fragments resist compaction, and large spaces in between give free drainage with drier conditions on top that discourage weed seed germination.

Apply mulches in early summer after the soil has warmed and growth gets underway but early enough to help retain winter moisture.
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For making no dig beds:
This involves top dressing the soil with good garden compost. It requires a large amount to maintain a good cover.

More organic gardening compost:
With organic gardening your compost is the key to fertility, indeed that applies to all outdoor gardening.

Don’t forget to maximize the source material for making your own organic gardening compost. You can make more by collecting vegetable waste from the green grocers, leaves from the local council; neighbours and friends will give you weeds, grass cuttings and hedge trimmings; horse manure may be got from local stables etc...

More about organic gardening compost.

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