If you’re planning to multiply your plants by planting seeds or by using different propagation methods you will be needing potting compost to ensure a prosperous and healthy growth of the plants. Planting in pots with essential ingredients is the whole point of potting compost. It is defined as a method in which plants are grown into pots or containers. You don’t have to necessarily make compost from scratch with what you have to throw in your bins, but you can make a homemade potting mix as part of your project.
Types of Potting Compost
There are packed potting compost available in store that you can mix with other ingredients to achieve the best potting mix recipe.
This compost type is for general use. It is reliable to use for most plants but not all plants. It is best to use for small patio plants. This compost is usually made with peat but there is also a peat-free option.
John Innes Compost
This is a loam-based compost that does not dry easily. It is formulated and developed by a gardening institute. They have different formulations with different functions.
This specialist compost is used for plants that have a special need such as ericaceous plants that won’t thrive in soil with alkaline.
To give you an idea of what you need to prepare for your DIY potting mixes, here are some of the usual ingredients for your mixes.
Sphagnum Peat Moss
This ingredient is one of the main ingredients usually used for most potting soils. The sphagnum peat moss is a stable material that doesn’t easily break down. It is commonly available and inexpensive. It is light but it’s bulky to fill your potting mix.
When watered, this material allows proper draining but stays damp but also allows air to be absorbed. However, this ingredient has low available nutrients and an acidic pH. To balance the pH, you can add Limestone to your potting mix if you are using the Sphagnum moss.
As mentioned, Limestone neutralizes peat-based potting soil. This mineral can be found in natural deposits, mined and pulverized before adding to your soil mix.
Coir is a by-product of the coconut industry. It has similar characteristics to sphagnum moss but with more nutrients. Coco coir fibre is a bit expensive but it is a sustainable material with an almost neutral pH.
This ingredient is a mined mineral prepared with heat for it to expand to become light particles. Vermiculite provides elements such as calcium and magnesium to your potting soil. It increases the porosity of your DIY potting soil mixes as well as in the available commercial mixes. One of its properties is to increase the water-holding capacity of your soil mix.
This small rock is mined and volcanic that looks like small white Styrofoam balls once processed with heat. Perlite is a lightweight and sterile material that can hold three up to four times of its weight in water. With its characteristics, Perlite increases pore space and allows better water drainage.
Coarse sand is used to add weight to your potting mix. It has the characteristic to allow adequate water drainage. Mostly popularly mixed with soil for cacti and succulents.
Fertilizers are used and mixed with your potting soil to provide more nutrients that can’t be found in the other ingredients. You can use natural fertilizers or commercially made to add to your soil mixes.
Compost contains a lot of microbes that are beneficial to your soil mixes. It is rich in nutrient content with extensive water-holding capacity. It promotes healthy plant growth when mixed with your potting mix. However, it is not recommended to be used for seedlings.
Composted Wood Chips
Wood chips help in creating pore sizes to provide a clear passage of air and water in your mix. Recommended to be included in your soil mix for potted perennials and shrubs.
Making your Own Potting Soil Mix
Before you start making your homemade potting mixes, understand that there are different types of potting mixes to use for different purposes. It would be a waste if you buy ingredients just to discover that they’re not compatible with your garden plants. You also have to prepare a large or ample size container where you will mix the ingredients such as a wheelbarrow. You can use a shovel to mix everything efficiently for an effective and consistent result. You can use the following mixing recipes suitable for your need:
General Purpose Soil Recipe
This potting mix recipe is fit to be used for flowers, tropical plants, and vegetables. Mix together:
- 6 gallons of sphagnum peat moss or coconut coir fibre
- 4.5 gallons perlite
- 6 gallons compost
- 1/4 cup of lime for sphagnum moss. If using coir fibre no need to add lime.
- 1 and a half cup of DIY container fertilizer blend or you can use 1 and a half cups of any granular, commercial, organic fertilizer
To make a DIY container fertilizer blend you just have to mix 2 cups of rock phosphate, 2 cups greensand, half cup of bone meal, and a quarter of kelp meal.
Recipe for Seed Starting
- 2 gallons of sphagnum peat moss or coconut coir fibre
- gallons vermiculite
- 1-gallon coarse sand
- 3 tablespoon of lime for peat moss
Homemade Potting Soil for Seed Transplant
- Option of 2 gallons of sphagnum peat moss or coir fibre
- 2 gallons vermiculite
- 1 gallon screened compost (fine)
- 3 tablespoon of lime for peat moss mix
- 2 tablespoon organic fertilizer or your DIY fertilizer blend
Potting Soil Mix Recipe For Houseplant
- 2 gallons of sphagnum moss or coir
- 1.5 gallons perlite
- 2 cups coarse sand
- 3 tablespoon lime for peat moss option
- 2 tablespoon granular, commercial organic fertilizer or your DIY blend
Potting Soil Mixing Tips
- One of the main keys is keeping any potting mix light. The lighter, the better. Absorbent and loose mixtures allow adequate flow of water, air, and fertilizer to the roots to be soaked up quickly, which is also necessary for container gardening.
- Sand and Perlite helps in the rapid draining of water. This is applicable for succulents, cacti, and lavender. You can add extra to ensure efficient drainage.
- For great moisture retention as needed by ferns and woodland flowers, add extra coir or vermiculite.
- Understand the required pH of the plants your will be planting. You can add Limestone or soil sulfur to lower the pH and lime to raise the pH.