In this article we will talk about what potting mixes to use, and how to make them.

Potting MIxes

Some terms commonly used:

  • Field Capacity: Is when squeezing the medium, you can no longer get any more moisture out.
  • Well Draining Components: Like Perlite or D.E. the courser this is the better. This will help prevent your mix from being waterlogged and drowning your plant.
  • Water Retaining Compnents: Like Peat Moss, Coco Coir, Vermiculite, Pine Bark, and LFS. These will help with keeping the mix wetter and not drying out.
Peat Moss

 

  • Water Retention: Peat moss holds a good bit of water, which helps keep the soil wetter... Until it dries out then it's a different story. When peat moss dries out it becomes EXTREMELY hard to rehydrate and even becomes hydrophobic, so you pretty much have to dunk it or sit there like a statue for a bit pouring water. That is why I like Coco Coir more than peat moss.
  • Why to Use: It is one of the cheaper potting mix components, it is widely available at box stores or garden centers, and it's fairly light when dry compared to other components like compost.
  • Why not to Use: Peat moss as mentioned above is very hard to rehydrate when completely dried out but if it gets to that 
  • Acidic pH: Peat moss has a pH of 3.0-4.0 which is too low for figs, but when mixed with powered lime or hardwood ashes... 😉 it is just right.            Note: Figs prefer a pH of 6.0-7.0.
  • How to Use Peat Moss in Potting Mixes: To create a balanced potting mix for your figs or other plants, you should combine peat moss with other components like perlite, compost, and D.E., a potting mix that uses it benefits greatly from some well-draining component like D.E. or Perlite.
Coco Coir

Why you should use it

  • Water RetentionCoco coir retains water well and should be combined with a well drainer for best results. I like it more than peat moss because it is easier to rehydrate if it gets dry. 
  • Price and general info: Coco coir is a bit pricey, but I think the success rate is well worth it usually about $20-$25 per brick. It usually comes in a dehydrated brick, so you need to rehydrate it. Put it in a cloth pot then run a hose over it and let it sit for a few hours. 
  • How to Use Coco Coir in Potting Mixes: To create a balanced potting mix for your figs or other plants, you should combine coco coir with other components like perlite, compost, and D.E. Coir holds a nice amount of water when wet, so you want some well-draining component like D.E. or Perlite, because no one wants a drowned cutting.
  • Warning: There have been incidents where a manufacturer has used salt in the process of making the coir, this salt is not good for your figs, so we always wash the coir before using.
Vermiculite

 

Why You Might Use It:

Water Retention
  • How to Use Vermiculite in Potting Mixes: To create a passable potting mix, vermiculite can be combined with other components like... well I guess little bit of coir and a good bit of perlite and or D.E.
  • Misinformation: There is much misinformation out there about this medium. It does not drain well as it adsorbs water and expands unlike perlite.  I prefer D.E. more as it does not expand as much when wet and I can sift out the fines and use them as dusting for Pest Control.
 

 Why I don't like it:

  • Don't I don’t like Vermiculite personally and do not use it. I also do not recommend it for anyone as I do not see any advantage to it over say peat moss or coco coir.
Long Fiber Sphagnum Moss 

Benefits of Long Fiber Sphagnum Moss

  • Water Retention: Sphagnum moss can retain a significant amount of water, keeping the soil moist for longer periods.
  • Antimicrobial Properties: Sphagnum moss has natural antimicrobial properties. 
  • Acidic pH: It naturally has an acidic pH of around 3.0-4.0 so you need to add some lime, even for acid-loving plants.

 Uses of Long Fiber Sphagnum Moss

  • Potting Mixes: It can be used as a component in potting mixes to improve its moisture-holding capacity and anti-microbial properties. For figs and those garden seeds too.
  • Propagation: It's often used in plant propagation, especially for air layering.
  • Soil Amendment: It can be mixed into the soil to improve its moisture-holding capacity and anti-microbial properties. 
  • For Potting Mixes: I do not use LFS for potting mixes as I think it's too expensive to mix up and should be used only for air layering, but if you wanted too here's how I would do it. Combine the long fiber sphagnum moss with D.E. or perlite and maybe a little bit of coco coir. 
  • For Air layering: This is my favorite way to use Sphagnum Moss. You should use this for air layering, as it works very well, and I think it's the best medium for the job.
D.E.

How to use it

This can be used on its own as a mix and we have had a good success rate with that, but we preferred method is to mix it 1:5 D.E. to Coco Coir (Follow the Tree Pop method) this we have had excellent success with it.

Benefits of Diatomaceous Earth

  • Moisture Retention: It absorbs excess moisture, improving drainage and preventing root rot.
  • What to use it for: D.E. should be used as a well drainer that helps to keep the mix well draining.

Considerations

  • Pest control: Fines only!: DE acts as a natural insecticide, effective against various pests like aphids, whiteflies, spider mites, ants, and more. 
  • D.E. can usually be found under the name Opti-Sorb at auto stores as an oil absorbent. Note: Thrifty-Sorb is calcinated clay NOT D.E. and is not a suitable substitute.

Common "Premixed" potting mixes

Miracle Grow

Miracle Grow

  • Ingredients
    • Peat moss and or coco coir, bark and other forest by-products, compost, perlite, sometimes charcoal, sometimes sand - and then fertilizer and wetting agents are added.
    • There were some reviews that had problems with there being rocks in the mix. Several reviews said that the mix contained to much course pine bark as well.
  • Should I use this mix?
    • I would be cautious about using Miracle Gro mixes because they have changed the formula for some of these products, so who knows if they will change this one and it ends up being "A fungus gnat explosion" to quote one review of the garden soil mix.
    • The price for this mix seems to be around $10-$15 per 1.5 cubic foot bag depending on what box store or online retailer you get it from.
  • Alternatives?
    • I would use HP or BX Promix instead or make your own mix as it will be cheaper than Promix or MG. So, over all I would use my own mix or Promix over Miracle Gro. Sorry MG 🙁
PROMIX

PROMIX

  • Ingredients
    • Peat moss, Perlite, Dolomitic and Calcitic limestone, Wetting agent, Mycorrhizae - endomycorrhizal fungi (Glomus intraradices) Depending on if you get the M version.
    • The reviews had almost nothing bad to say about it. Almost all had a great experience using this mix.
  • Should I use this mix?
    • I would definitely use this if I did not have the ability to make my own mix. Most people using this mix regularly report having great success with it.
    • The price for this mix seems to be around $10-$12 per cubic foot depending on what box store or online retailer you get it from. So, it's a bit pricier than Miracle Gro, but I think it's worth it.
  • Alternatives?
    • I would use Promix instead of Miracle Gro or make your own mix as it will be cheaper than Promix or MG. So, over all I would use my own mix over Promix then MG.