What is seed compost
It’s often convenient to use your own materials for making compost. This organic alternative saves you money, can be specially adapted to your plant needs and eliminates those heavy loads. Gardeners of bye-gone days always made their own compost.
- Garden Soil
- Garden Compost
- Re-used Compost
- Leaf Mould
- Worm Compost
- Coir Fibre
- Sphagnum Moss
- COMPOST RECIPES
- Recommended Recipes
- John Innes Recipes
But if you wanted information on garden composting click here.
Attributes of compost
Any growing medium should bind sufficiently to support plants. The organic component should be stable, that is, it wonвЂ™t readily decompose to cause slumping. It should normally hold plenty of water and provide ample aeration.
Seed compost especially should be well aerated and warm, but contain little available nutrients or salts.
Compost for growing-on and plant containers should hold moisture and contain ample nutrients for the growing plants. Add to all this the individual requirements of different species.
Materials for making compost
Knowing the attributes of compost ingredients gives you an indication about the effect of including them in a mix or of changing the relative amounts.
Fine particles as in clay give fine pore spaces that hold water tightly and are more often saturated. Course particles, as in grit, provide larger pore spaces that allow water to drain through and the pores which then contain more air.
Garden Soil: Sandy and organic soils may be used in making compost. But soil used alone behaves differently when confined in small volumes. Pot walls alter the water balance and dry the soil which then hardens. The microbial population may not develop normally which affects nutrient supply, while weed seeds and disease organisms present a greater hazard to seedlings and plants.
However garden soil may be used as a constituent when mixed with other components and when pasteurized before use. See below.
Loam: Good loam is made by stacking turves upside down and covering for 6 вЂ“ 12 months until the grass roots decompose. It is then sieved and pasteurized. This kills weed seeds and potentially harmful microbes. Sterilized loam is used in John Innes formulae.
Loam provides bulk and a fine texture but may become hard and impenetrable when dry. The high nutrient exchange capacity of loam is valuable for potting mixes that also include non humus organic matter like peat and leaf mould. Shortage of loam supplies led to the development of soiless compost. When buying loam, check it comes from a good source.
Garden Compost: Use only fully matured and sieved garden compost for making compost. High humus content holds water and contains plenty of nutrients. It helps to bind the growing medium. Adding grit, vermiculite, or perlite, will improve aeration when the mix is used in pots.
A ‘stale’ bed of garden compost can be used to remove germinating weed seeds before making compost for potting. Garden compost is easily made at home but it can also be bought locally. You need to check it is free of contaminants.
Re-used compost: Proprietary or rich medium used for growing tomatoes or cucumbers may be re-used in making compost for less hungry plants or seeds. DonвЂ™t use if previous plants infected by disease and always pasteurize before re-use.
Pasteurizing: This is done to kill weed seeds and active disease organisms while leaving useful microbes to re-populate. It is done by placing material in an ordinary oven at 80 0 C for 30 minutes. I suggest saving energy by pasteurizing in the oven directly after cooking. Use an earthenware or tin container, certainly not plastic. Pasteurizing may create a smell. I donвЂ™t recommend microwaving mineral soils, it could be hazardous.
Leaf Mould: Should be made from fully decomposed leaves (perhaps 2 years old) and sieved. It has a course crumbly texture providing drainage and aeration while being moisture retentive. It does not however, contain abundant nutrients and may be contaminated with weed seeds or disease.
Shredded conifer leaves should only be used to make growing medium for Ericas. Avoid using evergreen leaves like holly, or laurel.
Leaf mould can be used directly for making compost to germinate seeds and is useful for potting mixes and adding to containers.
Worm Compost: Like a jelly when fresh, the high humus content holds water and helps to bind the soil. Adding sand, grit or loam will increase aeration, improve draining and make a more open consistency. Like peat, worm casts do not re-wet easily after drying out. They may not be stable due to continued decomposition which may then cause slumping.
Worm casts are rich in nutrients, especially nitrogen, and its phosphates are more available (ideal for roots). Worm casts are especially good for germinating seeds. When making compost I suggest adding worm casts in a lesser proportion or, add to holes before dropping seeds in.
Coir: A byproduct of coconut production and made from pith that surrounds the fiber. It is highly water absorbent; also, high in lignin and more resistant to decomposition than peat.
It is naturally low in nutrients but subsequent processing can result in higher potassium salt levels. I have read that coir may lock up trace elements like copper and molybdenum which could in turn cause nitrogen deficiency symptoms.
Coir has a fine rather loose consistency. It is a good base for making seed compost, but could вЂswampвЂ™ fine seeds. In nature Coir fiber surrounds the coconut seed and is said to contain natural rooting hormones. When used directly as a seed compost take care not to overwater. Also, transplant when first leaves appear. It is sold as solid bricks and reconstituted by placing these in water.
Peat: Sphagnum peat is used abundantly for making compost. It comes from the dead remains of sphagnum moss accumulated over thousands of years. Real concerns about environmental impact have led producers to look for alternatives. However many gardeners regard peat as irreplaceable in the garden.
Peat is a stable organic material not given to slumping or rapid decomposition. Peat holds plenty of water and care needs to be taken not to over water seedlings. Loam, sand, vermiculite or perlite are useful additives to mix with peat to provide the larger structural pores necessary for sufficient aeration and drainage of excess water. When peat does dry out it difficult to rewet. Peat has no nutrient value until it decomposes to humus when it has high nutrient exchange capacity.
Sphagnum moss: This is made of living moss plants, it is not moss peat. It holds lots of water and has been used in hanging baskets, and for creating a moist atmosphere around plant leaves. It may also release chemicals that inhibit disease organisms. However, I would prefer to see alternatives used.
Sand: Sand is the silicate mineral quartz and has no nutrient value. Fine sand should not be used in making compost as it blocks pores. Course or sharp sand is important for adding larger pore spaces for free drainage and increased aeration. Silver sand has the lime removed.
Vermiculite: It is made from clay minerals. The internal pore space of Vermiculite particles absorb plenty of water while the external space is large to ensure free drainage and aeration. Vermiculite also provides a high nutrient exchange capacity.
Perlite: Fine grades of horticultural perlilte have surface pores enough to absorb plenty of water. Like vermiculite it provides external space between particles to ensure better drainage and aeration. A big advantage to perlite is in being very light.
A big advantage of making compost yourself is that you can deal with smaller amounts, reduce space for storage, put waste material to good use and better adapt the compost to suit plant needs.
You should experiment and try out your own mixes. Make use of the material that you have available in your part of the world.
The garden hand claw is an excellent tool for mixing small quantities together in a bucket or tray.
Fill a plastic bag with alternate 3″ layers of leaf mould and comfrey leaves cut in autumn. Ventilate the bag and store until spring – attributed to Terry Marshall and published in Grow Your Own Vegetables by Joy Larkcom
3 parts leaf mould, 1 part worm compost.
The well-known John Innes compost recipes. – compost sold under this name can vary, as the name was not patented.
NOTE: These John Innes compost recipes are not strictly organic where they include Superphosphate or Potassium Sulphate. These formulae detail what should be in the bag and may help you in making compost see below
John Innes seed compost: In the following loam is sterilized and peat and loam are passed through 9mm sieve.
John Innes Compost for Cuttings:
1 loam, 2 peat, 1 sand no fertilizer.
John Innes Composts No’s 1 – 3:
Mix 7 loam, 3 peat, 2 sand
plus one of the following fertilizer mixes:-
J.I. Compost No. 1 Fertilizer to add per 1 cubic metre of mix.
J.I. Compost No. 2 Fertilizer to add per 1 cubic metre of mix.
J.I. Compost No. 3 Fertilizer to add per 1 cubic metre of mix.
You’ll notice that JI 2 has 2x the fertilizer in no 1, and JI 3 has 3X that in no 1.
The composts are used in increasing order when potting on. So delicate young plants are not harmed by strong fertilizer while robost plants in large containers get enough fertilizer to last.
UPDATES: to this page will consider fully organic alternatives like replacing superphosphate with Bone Meal or Rock Phosphate and making compost mixes for organic tomatoes.
John Innes Ericaceous Compost 2 loam, 1 peat, 1 sand. Fertilizer to add per 1 cubic metre of Ericaceous mix.
Try making compost at home for seeds, growing on, and pots
What is seed compost
New to gardening? Confused about which peat-free compost is best for you? Here we explain the differences between our Soil Association-approved multipurpose, potting and seed compost.
Peat-free seed compost
Ideal for seeds and cuttings, this is a mixture of organic coir, vermiculite and Fertile Fibre nutrients.
The coir – made from coconut husk – is great at encouraging germination and fast rooting. The small specks of white and gold vermiculite help control watering. So there’s no need to worry about over-watering. If this happens, the vermiculite will soak up the excess. It will then slowly release the water as the compost dries out.
Tips on using seed compost
You can use the compost straight from the bag.
- Place it in seed tray or pot. Be ver careful not to over compact – simply tapping the container on a hard surface is enough.
- Place seeds on top.
- Cover with the same depth of compost as thickness of seed. So if seed is 1 mm thick, cover with 1 mm of compost.
Don’t over-water. Coir has excellent water holding capacities so this can be a problem. We recommend watering little and often. The compost may seem dry on top but will still be wet underneath, so it’s always worth double checking before watering.
Multipurpose peat-free compost
An excellent all round general use growing medium. In our compost, it has the same ingredients as our seed compost. But there’s less vermiculite and more nutrients. The nutrient levels are low enough for germination and high enough for established plants. It’s a popular choice amongst our customers growing crops such as wheatgrass for juicing.
Potting peat-free compost
Plants in pots and containers need more nutrients as they can’t draw up anything through the soil. Our blend is a rich, dark mix of coir, vermiculite, bark, loam and our unique organic nutrients.
Potting compost helps ensure strong, vigorous, healthy and sustainable growth.
Tip: Use it as a growbag
Many of our customers just use the bag as a growbag and plant directly into it.
Not sure which is right for you?
Just give us a call on 01432 853111 or drop us an email at [email protected] if you’d like more information.
2 thoughts on “ What’s best: Multipurpose, Potting, Seed Compost? ”
We use ONLY Fertile Fibre Seed Compost for all our seeds. We get uniform germination and there is enough nutrient to keep the seedlings going if we are a bit late pricking out!!
For raising cuttings we use sieved potting compost and then add a medium grade vermiculite. The ratio of sieved compost to vermiculte varies according to the cutting material, but is typicaly 3 parts sieved potting to 1 part medium vemiculite. This gives a more open rooting medium than the straight seed compost, which suits our mist propagation system better.
We use the professional grade potting compost for virtually all our potting on. For the majority of plants we use it “straight”, ensuring it is well fluffed up and not over compacted ( I cannot stress the importance of this enough!). For lavender and rosemary we mix 2 parts potting with one part of “ballast” (the stuff you get from a builders’ merchant) or sharp sand, this gives the really sharp drainage these plants need and reduces the nutient levels to promote better flowering.
The results – our customers say they have never seen such healthy plants!
i am growing tomatos in my green house for the first time using the autopot system—-I have purchase from you 120 ltrs of perlite. I have been recomended to mix the prelite 50/50 with compost. What do you recomend
Find out the difference between Fertile Fibre’s seed, potting and multi-purpose compost.