Urban gardening or small-space gardening in containers is on
the rise! And the number of people growing plants indoors is also on the rise.
The most important aspect of container gardening is the potting medium used,
because this, along with light and moisture will be the most important factor
to help your plants grow healthier and disease free.
I never use the commercial potting mixes available, which are infact too expensive.
I rather prefer to make my own homemade potting mix recipe for both my indoor
and outdoor plants
Now, lets start looking at the ingredients we use to prepare our indoor soil mix, one by one. We will list out the formula or the recipe with the proportions of each ingredient used, shortly.
- Garden Soil: This forms the major component of an outdoor potting soil recipe because one of its major functions is plant anchorage which is very important for outdoor plants which can easily knocked down by strong winds. We will use garden soil in our indoor potting mix too but in smaller quantity.
- Cocopeat or Peat Moss: I prefer cocopeat because its easily available and inexpensive and has a neutral PH. Plus mixing this with garden soil removes the compactness of garden soil and makes it well draining. This forms the major ingredient of our indoor potting mix. Its available as a compact brick or in powdered form. The coco peat brick can be easily reconstituted into cocopeat powder by mixing it in water. One brick of about 5 kgs will give you a large volume of upto 75 liters of cocopeat powder.
- Compost: like vermicompost or decomposed cowdung or horse dung powder or both. Compost manure is an essential component of any potting mix to provide the major and minor plants nutrients like the NPK – nitrogen phosphorous and potassium along with the trace elements. We have already discussed this in our previous episode on the basics of indoor gardening.
- Neem Cake Powder: This is optional. But adding this will take care of any fungus and harmful bacterial growths and protects your plants.
- Bone Meal Powder: This is again optional but very useful if you are growing vegetables or flowering plants indoors under grow lights. This will induce flowering and fruiting if mixed in potting soil.
- Perlite, Vermiculite or Pumice: All these serve the same purpose of making a well draining potting mix plus adding a good aeration system for roots. Among these Vermiculite should be cautiously used, because it holds lot of moisture and can rot you plants especially succulents. Vermiculite can be used for water loving plants like lucky bamboo and others. Pumice and Perlite are the best options. Among these two, the main drawback of Perlite is it gets crushed into powder if you use it along with too much garden soil and in this case pumice is the best if available. Garden Pumice or horticultural pumice is available in various grades or sizes and it does not get crushed unlike perlite. You can find the links to purchase these items online in the description below.
Now quickly, before the formula
or recipe, lets know the difference between Potting Mix and Potting Soil.
Potting Mix is simply a mixture of all the above ingredients minus the garden
soil. That’s means it is a soil less medium. On the other hand, Its called
Potting soil when you use garden soil in the mixture. That’s simple! But most
often these two terms are used synonymously.
Well, here in this recipe, considering the importance of plant anchorage, we
will use garden soil too but in small quantity.
Now lets look into the actual recipe of this indoor potting soil.
- Cocopeat forms about 40 to 50 percent of this mix.
- Garden soil about 10 or 20 percent.
- Perlite or Pumice or both about 20 percent
- Compost like vermicompost or Cow dung compost or a mixture of both 20 percent depending on what you want to grow. For veggies and flowering plants, you can increase this to 30 percent. For ornamental plants 10 to 20 percent is sufficient. This can also be added later on to the top layer of the soil – a handful of it per container once or twice in a month.
Optionally you can add 5 percent bone meal plus neem cake powder.
So, Today we will learn on this topic and use 5 simple steps to revive or rejuvenate expired or old garden soil.
The soil is the most important growth medium for plants which provides them the necessary nutrients and moisture for proper growth. The useful life of a potting soil recipe depends on whether or not it is currently in use. Todays focus is mainly on unused potting soil and how to recharge it with few simple steps. The regular or the used potting soil with plants growing in it has the necessary activities in it like the beneficial microbial activity and you feeding the plants regularly with fertilizers and so on. So what happens with Unused potting soil. It actually lasts roughly about six months before it degrades in quality with depletion of nutrients and the beneficial microorganisms go into dormancy that is a state of inactivity. But one point to remember: the used soil with plants growing in it should be replaced every one or two years for best results in container gardening.
Now the 5 Important Steps to Reuse old potting soil and revitalize it and how to make potting soil or the best potting mix:
- Remove old plant matter like the roots, twigs or leaves. Pull out any dead plants and weeds and other garden debris.
- Fluff and till the soil, make a layer of about 3 to 4 inches. Break up any large clods as you loosen the soil. And sprinkle some water on the top and Dry it in sunlight for atleast a week. You can cover with a polythene sheet after 2 days so that weeds do not invade this layer and also this protects from rains if any.
One Simple Hack here to check whether the soil is ready for further processing. Squeeze a handful of the soil into a tight ball. Flick the ball with your fingers. If it falls apart, the soil is dry enough to work. If the ball retains its shape or only develops a slight dent, the soil is too wet and must dry for some more time before you can proceed to revitalize it. - Soil PH Test – This step is Optional. You can do a soil ph test before and after the process of adding nutrients. Based on this you can adjust the nutrients to properly adjust the soil ph to your desired level. You can check related videos on this like wood ash in gardening, and also Vinegar or Alum in gardening to make it more acidic or alkaline and many other similar videos at my channel – https://youtube.com/gardentips.
- Adding nutrients to the soil – Mix it with fresh compost like decomposed cowdung powder or any Compost at a 1 :1 ratio or atleast 30 percent. To combat fungus and other harmful pathogens organically you can add about 10 percent Neem cake powder if available. Optionally you can add some gypsum and lime dust and other nutrients or components like bone meal powder, little Epsom salt, and other stuff, like how we make our all purpose or the universal potting soil mix. You can check out my video on this topic from https://youtube.com/gardentips.
- Mixing: Mix it thoroughly – this is also an important step so that your containers get everything right in proper proportions – neither too less nor too much.
- Then lastly, If you do not plan to use it right away, Always store the soil covered and in dry areas with low humidity and away from dampness.