Home made potting mixtures can contain many different types of ingredients found around the home and garden. Some even include a base of ordinary garden loam, though I don’t recommend this.’

The ingredients you choose should allow for good water retention due to the environment if the pot especially terracotta or clay pots. The ingredients should also contain enough loose organic matter to allow nutrients to remain held in the mixture for the plants to use as needed.

Most of the ingredients you use will already be around your home but you may need to purchase one or two things:

1. Garden Compost. This should be a combination of old hay and lawn clippings. Garden compost  should be well aged so it is ideal to maintain  a separate compost heap you can leave alone for several months specifically for potting mix. Compost should be placed in a black plastic bag and left in the full sun for a couple of weeks to solarise and kill any remaining weed seeds. This should form the basis of a home made potting mix.
2. Draining aggregate. This may be the only thing you will have to buy. The cheapest option would be Perlite based Cat Litter available from your local supermarket. A simple no name brand will be suffice.
3. Pulverised Sheep or Rabbit Manure. This will provide an immediate nutrient source and will also act as a retention source for  the addition of future Nutrients as well as a basis for the duplication of bacteria.
4. Worm Castings (Vermicast), is an ideal addition to a potting mix for conditioning, fertilising and for adding worm eggs which are contained within the vermicast. When these eggs hatch the worms will help breakdown the organic matter in the potting mix. There is an old wives tale that worms can damage a plant in a pot but this is not true.
5. Composted Wood Chips. These make an  ideal addition to a potting mix. Ideally made using a home shredder, these extra-fine wood chips provide aeration and bulk as well as an additional drainage aggregate.

An equal measure of each of these ingredients should be mixed together for a standard potting mix. Variations could include a finer mix for seed raising using only vermicast with draining aggregate or a coarser mix for orchids using an extra helping of drainage aggregate and composted wood chips.

Some years ago when I was first trialing grass hay in the compost, I placed an ad in the wanted to buy section of the local paper. The ad simply read “Wanted – Grass Hay – The older and wetter the better – Suitable for Garden mulch and composting” It was a simple ad so I was surprised by the number of phone calls I got.

When the hay is wet and old keeping it in a bale is no easy task but I managed to get several bales home. I kept a couple of bales for adding to compost between layers of lawn clippings and I used the rest of the bales on my pre existing vegetable garden The Hay was quiet old and half rotten so it didn’t take long to break down. The following season there was sufficient rotten hay to plant several rows of tomatoes in without breaking the soil surface. These tomatoes grew almost to my own height of over 5ft 6inches.

I often use grass hay now for building up soils and adding to garden beds over winter to prevent weed growth. Hay breaks away easily into bricks and packs tightly stopping weeds from growing through.

Some tips for using rotten grass hay in and around the garden.

• I grow potatoes directly under grass hay and plant lettuces in the same spot the following season. The hay has all but completely broken down by the time the lettuces are planted. The following season Turn the soil deeply and plant carrots. The previous 2 years have softened the soil making it easy to dig and giving the carrots a soft soil to develop in.

• I always add pre or partly rotten hay into the compost heap in between layers of fresh green lawn clippings. The lawn clippings build up the heat and the bacteria has already started working in the hay. It doesn’t take long before the compost is ready to use.

• Hay that has previously rotted on a vegetable garden can be raked off if required and used as mulch around roses or in annual flowerbeds.

• Seeds in grass hay are rarely a major issue as they usually germinate on top of the ground or in the hay itself as it decays. Any green can be easily pulled off or left to grow and dug in before they flower. Any twitch or rhizome grass species should be easily identified and removed by hand. Before it gets out of control.

You can also make your own wood chips by trimming your own yard tree waste using a commercial chipper or shredder. Commercially available woodchips are often very coarse. A shredder will aid in reducing the size of the chip, allowing for a tighter weed suppressant.

Wood chips can be purchased from local nurseries or organic garden centres. They can also be purchased directly from a timber mill or wood chip production facility.

Naturally coloured wood chips are available. These look more like pine bark or a natural ground covering. One of the down sides to fresh woodchips is they look fake. There are various ways to colour woodchips but the most common and chemical free method is with a tea stain or with natural minerals. Be sure to ask your supplier what was used to colour them to ensure you maintain a chemical free organic garden.

• Woodchips are used in the garden as an organic weed suppressant and ground cover. Newspaper or cardboard can be placed under woodchips to assist in preventing weed growth.
• They can also be added to compost heaps. When using as an organic compost additive, I usually recommend putting them through a shredder for a second time to reduce their size. This allows them to break down much faster by increasing the surface area available to bacteria and worms. Fresh green lawn clippings should also be mixed through wood chips before adding them to a compost heap. The lawn clippings will help build up the heat a compost needs as well as adding necessary green material to the mix. Wood chips can pull nitrogen from your compost heap. Adding plenty of lawn clippings, chicken manure or other high nitrogen material will help replace depleted nitrogen.
• Woodchips make an ideal covering for a garden path. They will help suppress weeds and they look natural as they decay.
• Woodchips are an ideal ground cover under children’s play equipment. They provide a soft play area, help suppress weeds and prevent the ground from becoming muddy during wetter months.
• Wood chips are ideally added to nesting boxes and the ground of chicken yards and in calf sheds on farms. They are an easy way of soaking up excess moisture and they are easy to shovel out and into a compost heap when finished.