Some things to add to any grow medium - tricks of the trade

As a soil grower, one of my favorite mixes is three parts top soil 1 part vermiculate 1 part perlite 1 part sand. It is what I use in my greenhouse. I have been adding part coir to the mix starting last semester which will cause the soil to hold more water. Basically, you can adjust your soil to your plants or your watering habits -- adding more sand and perlite will increase drainage while coir vermiculite and soil will increase some water retention. You could also try adding screened compost to any mix (Compost article) this will improve water retention and aeration as well as supply most nutrients including micro nutrients. Experimentation will lead you to find the best medium for your plant and your growing environment, one size does not fit all. I used to like to sit in front of my plants each day for awhile, and I would water them a bit each day. For this I made a mixture with a lot of drainage. Now, I am busy and I don’t even look at the plants each day sometimes, so I have more vermiculite and coir so that I know the plants won’t dry out.
One thing you could try no matter what you grow is adding Epsom salts, one tea spoon per gallon which will supply Mg and sulfur. Also, know that if you use time release fertilizers they are usually meant for outside use and their breakdown (release) is based on temperature. In other words, indoor growers will have higher temperatures and faster breakdown. First, know this means you will get a higher amount of fertilizer and second, the fertilizers will not last as long. If you want the fertilizer to be in the medium for 6 months, you should get 9 month release. Since the release is quicker, be conservative in how much time release fertilizer you use.
I hope this month’s articles on mediums help you to build a better medium for your plants. As always, I encourage you to experiment and find the right type of growth medium. Please feel free to write with questions or comments to askthedoctor@htgsupply.com, I would enjoy hearing some of the combinations of growth mediums you have used, which are the best and worst etc.

Hydroponics mediums
Pottings soil
Starter plugs

Good Growing,
Dr. E.R. Myers