Potting Soil Recipes and Soil Reconditioning

Potting Soil Recipes and Soil Reconditioning


  • Pass the garden loam through a 1/4 in (0.6 cm) sieve
  • Warm oven to 180 degrees F (82 C) for 10 minutes
  • Place on center rack
  • Place foil over tray and make sure the soil reaches the above temperature. Use a meat thermometer

Potting soils using garden loam

  • Potting soils should be placed through a sieve of the defined size:
  • Loam=3/8 in (1 cm)
  • Peat=3/8 in (1 cm)
  • Sharp Sand=1/8 in (3 mm) NOTE: do not use builder sand. Make sure the same is washed thoughly

John Innes Potting Compost

JI #1 Base

7 parts sterilized loam
3 parts peat
2 parts sand or grit
Fertilizer: 4 oz / 8 gallons (3 grams / liter)
Lime or chalk: 3/4 oz / 8 gallons ( 0.5 grams / liter)

JI #2 Base: Same as 1 but double the Fertilizer and chalk
JI #3 Base: Same as 1 but triple the Fertilizer and chalk

JI Seed compost: The fresher the sterilization, the better the germination

2 parts sterilized loam
1 part moss peat
1 part sharp sand

The loam and peat is put through in 3/8 in (9mm) sieve.

To each bushel or 8gal(36 L) is added:

1-2 oz (42gm) superphosphate
1/2 oz Potassium nitrate
4-6 oz (21gm) ground limestone

Ericaceous Mix: Use the base but leave out the Lime

Soilless: 3 parts peat and 1 part sand

Potting Compost: (same as above)

7 parts sterilized loam
3 parts moss peat
2 parts sharp sand

The loam and peat is put through a 3/8 in (9mm) sieve.
To each bushel (8gal/36l) is added

3/4oz (21gm) ground limestone
4oz (110gm) 14-14-14 Osmocote

This makes John Innes Potting Compost No. 1.
For a richer mix simply double the quantity of John Innes Base to make No. 2 or treble it to make No.3


Orchid Mix

1 part peat moss
6 parts fir bark
1 part medium grade charcoal

Cacti Mix

1 part compost
3 parts pumice or grit
1 part coarse builders sad
1 part of fine silt

Seed Starting #2

4 parts peat
2 parts perlite
2 parts vermiculite


9 parts coarse sand
5 parts peat
4 part pumice

Pumice is also used as the top dressing and to provide extra bottom drainage. Provide encapsulated slow-release
fertilizer with minor trace elements once a year and repot yearly.

Shade Mix

George Schenk’s recipe for the ideal soil for growing plants in shade.

1 part humus (compost, peat, leaf mold, etc.)
1 part sand
2 parts loamy soil (builder’s or riverside)

Blend in the above ratio. He further recommends screening both the humus and the soil so as to eliminate “roots, clods or rocks larger than a bantam’s egg.”

Cutting mix

1 part peat
1 part sharp sand

A. Knutson mixes

Cuttings: I use composted manure mixed with sawdust to root cuttings in — it works great; don’t need rooting hormones.

I use a a 50:50 vermiculite/peat mix to start seeds

Transplants and containers: 1/3 composted manure, 1/3 sandy loam, 1/3 peat moss


From Hobby Greenhouses in Alberta

Agdex 731-5

The Cornell peat-Lite Mix* is formulated for growing topical plants. The Foliage Plant Mix ** and the Epiphytic Mix** formulas are adapted specifically for their respective plant types and are modifications of the original peat-lite

Cornell has used Osmocote 14-14-14 and Peters 14-7-7 fertilizers with the tropical plant mixes with good results. Other fertilizers are omitted with the exception of dolomitic limestone and 20 per cent superphosphate which are added to adjust the pH and to maintain adequate phosphorus levels. A trace element mix is added to assure a balance of minor elements. Trace element mixes can be purchased from specialty gardening centers.

* “Cornell Tropical Plant Mixes”
by Russel C. Mott

**L.H. Bailey Hortorium, Cornell
University, Ithaca, New York

Cornell Peat-lite Mix

Mix 1/2 cubic meter each of sphagnum peat moss and perlite or vermiculite. Add 6kg
dolomitic limestone, 2.4 kg ammonium nitrate, 1.5 kg superphosphate, and 0.3 kg potassium chloride (omit if using vermiculite).

Cornell Foliage Plant Mix

The Cornell Foliage Plant Mix was developed for those plant that need a growing medium with high moisture-retention characteristics. Plants having a fine root system or possessing many fine root hairs are included in this group.

Material1 cubic meter
Sphagnum peat moss (screened
1/2 inch mesh)
Horticultural vermiculite (No.
Perlite (medium grade)0.25
Ground dolomitic limestone4.9 kg
Superphosphate 20% (powdered)1.2 kg
Fertilizer (10-10-10)1.6 kg
Iron sulfate0.4 kg
Potassium nitrate (14-0-44)0.6 kg
Granular wetting agent0.9 kg

Cornell Epiphytic Mix

The Cornell Epiphytic Mix was developed for plants that require good drainage, aeration and have the ability to withstand drying between warterings. Plants having coarse, tuberous, or rhizomatous roots are in this category.

Material1 cubic meter
Sphagnum peat moss (screened
1/2 inch mesh)
Douglas, red or white fir bark*
(about 0.5 cm size)
Perlite (medium grade)0.25
Ground dolomitic limestone4.2 kg
Superphosphate 20% (powdered)2.7 kg
Fertilizer (10-10-10)1.5 kg
Iron sulfate0.3 kg
Potassium nitrate (14-0-44)0.5 kg
Granular wetting agent0.9 kg

* Fir bark comes from Douglas fir, white or red fir, or redwood, ground and screened to a definite size. Finally ground bark (about 0.5 cm) has a dry weight of about 200 g per liter cube. Fresh bark has a pH of about 5.0. Upon weathering, it becomes slightly more alkaline. The bark contains some nutrients, but these will not meet the requirements of growing plants.


Potting Mixes from UBC Botanical Gardens


All the plant material coming into the Botanical Garden nursery, whether it is seed, cutting or bare root material, is grown in these mixes and the nursery has a 60-70% success rate of all these plant materials.


Alpine Potting Mix

4 Bushels of Lakeland coarse peat (to be measured)
4 Bushels of Turface -3 bags
3.3 Bushels of Aqua sand (AE3) -4 bags
2 Bushels of screened pasteurized soil (15%)

Add by weight

Aqua-Gro `G’
Osmocote 18-6-12
315 gms
340 gms
1250 gms

Seed Mix


1 Bushel of soil (screened and pasteurized)
1 Bushel of Fisons Sunshine “Ready-to-Use” Peat Moss (screened)
1 Bushel of Turface (pre-moisten with 2 gallons of warm water)


Dolomite GSAG
Truban EC 25%(Fungicide)

42.8 gms
21.4 gms

128.4 gms
64.2 gms
2.0 mls

Cutting Mix

5 Bushels of Perlite (horticultural grade)
4 Bushels of Peat (Coarse grade)
3 Bags of Aqua Sand (Equivalent to approx. 3 Bushels)

Add by weight:

Aqua-Gro `G’
195 gms
195 gms

Standard Potting Mix

Bales of Lakeland Coarse Peat
2 Bags of Supreme Perlite
1 Bag of Turface
6.00 Bushels
1.50 Bushels
17.0 Bushels

Add by weight:

Aquagro `G’
Osmocote 18-6-12
gms (56 gm per bushel)
515 gms (30 gm per bushel)
515 gms (30 gm per bushel)
2390 gms(140 gm per bushel)High
Rate1595 gms (94 gm per bushel) Low


High rate-Late spring and summer potting of general nursery stock, until August 15.
Low rate-Potting of Ericaceous plants or general nursery stock after August 15.


For Seedlings and Small Container Stock (21/4″, 3″, 4″) Add 3 bushels of screened, pasteurized soil to a standard potting mix to make it 15% soil and use low rate of osmocote 18-6-12.


If your collection of houseplants is small, the matter of soil need not greatly concern you. Your florist or a local greenhouse will supply the correct mixture at a reasonable price. It’s easier to buy a few bushels of earth for potting than it is to mix your own. On the other hand, as interest and the number of plants increase, you will probably want to give the matter more consideration and make sure that each plant has its roots buried in the kind of soil most agreeable to the species.

In The Garden Dictionary..’ which, by the way, ought be in every gardener’s possession. They cover all types of plants likely to be cultivated in the house. Mixtures 3 and 6, in particular, cover a wide range of requirements. In subsequent descriptions of plants, number will make reference to potting mixtures.

Potting Mixture 1

  • For potting rooted cuttings started in sand

  • 2 parts sharp sand

  • 1 part loam

  • 1 part leaf mold (or peat moss for acidtolerant plants)

Potting Mixture 2:
For transplanted seedlings and for cuttings when moved from Mixture 1

  • 2 part sharp sand

  • 1 part loam

  • 1 part leaf mold

Potting Mixture 3
For general potting, especially for such plants as the garden geranium, fuchsias, chrysanthemums, Sansevieria, Pandanus, palms, etc.

  • 1 part sharp sand

  • 2 parts loam

  • 1 part leaf mold or humus

  • 1/2 part dried cow manure

  • 1 5-inch flower pot full of bone meal to each bushel of the mixture

Potting Mixture 4
For plants requiring more humus than in Mixture 3, such as begonias, many ferns, primulas, etc.

  • 2 parts sharp sand

  • 2 parts loam

  • 2 parts leaf mold or humus 1/2 part dried cow manure

  • 1  5-inch flower pot full of bone meal to each bushel of the mixture

Potting Mixture 5
For potting many hardwoodcd plants such as azaleas, Ericas,Daphne, and certain ferns

  • 2 parts sharp sand

  • 2 parts loam

  • 2 parts peat moss

  • 1 part leaf mold or humus

  • 1/3 part dried cow manure

Potting Mixture 6
For most cacti and succulents

  • 2 parts sharp sand

  • 2 parts loam

  • 1 part broken flower pots or soft brick broken into small pieces

  • 1/2 part leaf mold or humus

  • 1 5-inch flower pot of bone meal to each bushel of the mixture

  • 1 5-inch flower pot of limestone (ground) to each bushel of the mixture

With material for preparing these mixtures on hand in the garage or tool shed you are ready for any eventualities as potting is concerned. Irrespective of the labor it is a source of great satisfaction to the deeply interested gardener to know that he is giving his plants the best start; and the plants show their appreciation with foliage and more numerous blossoms.

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