Are pine fines or diatomaceous earth a useful stressor for rooting purposes?

I am working on a theory and would like the brain trust to engage on this subject: concerning pine fines or diatomaceous earth, do they serve to induce quicker growth of roots through a stressor starvation method?

When I received my fruit trees that I ordered online, I chose to repot them with my own blend of potting mix. Many of them had a large quantity of pine fines in the mix that the vendor had initially used. There were many fine roots, some of which were holding on to the pine fines. I am wondering if the presence of these fine roots is actually a cry for help, a signal that the soil is not providing what the tree is seeking. I have predicated this consideration partly on the large quantity of fine roots that I’ve seen developed when people post pictures of the fig cuttings that they have rooted in Optisorb or similar diatomaceous earth.

Picture credit @Drew51

Picture credit @JCT

[there is a third picture that I would like to post here, but until I am able to locate it again I’ll constrain myself to those two above]

Maybe this is a good method for speeding the growth of many roots, then to be transplanted into better soil.


@Audi_o_phile, I don’t know how you come up with these ideas! You are must be a really creative, think outside the box person. :slight_smile:

Here’s another picture of a fig cutting grown in DE that seems to support that hypothesis.

Picture credit @Drew51.


If you want more visible roots sand is always a good option. The roots will try to seek out better nutrition.

Also there is the bottom watering method. In my area of interest with tip rooting… placing the pots in a tray of water after cutting from the mother makes the roots go down towards the water and is usually more successful. I use hot water heater catch pans.

DE holds onto water and is already millions of years old so it stays in place and is good for long term potting.

Pine fines added to potting mix is good for drainage… alot of potting mixes are heavy with peat which holds water well… but can also lead to root rot/molds etc. Its a good addition early on as it is slightly acidic for acid loving plants…but the real benefit is that it uses less nitrogen to decompose.

This guy has great success using his method… if you are into rooting.

Thank you @krismoriah, and yes, I am definitely into rooting!

All I know is that DE works for me so I keep using it!

@disc4tw, @Drew51, @JCT, anyone else out there using solely diatomaceous earth for rooting fig cuttings, with what frequency are y’all watering your cuttings? I just started a batch this evening with an OptiSorb-type of product.

I’ve heard people say that it is basically impossible to water too frequently with this product, but I don’t know what the minimum recommended watering schedule is.

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If you use a quart size pot or bigger, weekly should be more than enough. I haven’t touched my grape cuttings more than twice a month and they appear to be chugging along nicely.

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I just look at it. If the DE is starting to dry out, then I add water. Make sure all the water drains out and you do not have any held in the pot.

If the DE dries out too much, it can start to suck moisture out of your cutting and/or roots.


I had used DE only for some figs last year and it did ok but I definitely had things dry out too much in some spots of the cups. One week long trip away and a bunch were bone dry.

I switched to having a layer of pine fine mix on the bottom with some coir or peat on top and around the outer edge with DE in the center with the fig cutting. The roots grow through the DE and eventually will grab some energy out of the mix below.


I identify with your statement.

I make my own rooting mix which is what I had been using for rooting fig cuttings, but due to seeing all of the creative methods that others here have employed (accompanied by pictures), and my curiosity as to why some of these are so very effective, it has called into question my beliefs.

A couple weeks ago I began peeling large flakes of bark off of a dead pine that is already on the ground at my property. As of only a month ago you would have never found me considering incorporating a pine bark component into my oh so precious potting mix, and yet here I am, trying fig cuttings in straight DE pellets as well as considering the best way for me to reduce pine bark to pine fines.

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I havent seen this technique before… seems to work.

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I read some posts last night and a guy that says he roots thousands and thousands of figs to sell online says that he uses these

and then transfers them to buckets of sawdust.

He said that he had tried many other mediums but sawdust worked the best.

Not my idea or science… just passing along what i read…

I can tell just from the pictures that the sawdust shown there is from pine. I couldn’t tell you how many tree species I can identify just from the appearance of sawdust, but man is it a lot! I’ve got two contractor’s size garbage bags full of oak that we had cut in order to get a storm fallen tree off of the customer’s house.

Thank you for all of your assistance. One of the ways that I am trying to diversify my income stream over time is to start producing fruit trees for sale in order to make some portion of my money from something other than my day job, and fig cuttings are what I am starting with.

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If I am leaving on a trip and have cuttings rooting in DE, I’ll turn off any bottom heat and remove the cuttings from direct sunlight. They will keep for a week like that if there isn’t anything to accelerate the drying out process.

Best of luck to you… I am doing the same in a way.

Here is another interesting thread… mulberries are kind of like figs… so i think its relevant in a way.

I root mine in a pretty dark, cool area… as i want roots not foliage or the things that like to grow with UV and sunlight. For some reason folks think that the most nutritious soil along with UV lights and heat are the special recipe for rooting things… maybe it is… but i think that roots like darkness and coolness and dampness myself. So i create an environment that is Fall-like where supposedly 75 percent of root growth happens… whereas the mindset of most folks is to create a spring or summer like environment which is good for foliage…not so much for roots.

I just rooted dormant hardwood cuttings of blackberries which is very tough to do. I have failed using every method that you can think of… so i tried something totally different… I think there is at least 20 youtube videos of people sticking cuttings but never any results… likely they all failed.

@JCT and others, do y’all have your cuttings in open air, or do you keep them in a storage container with a lid?
This is the 12 inch tall, 56 quart storage box that I use to decrease evaporative loss and hold the heat in.

If heat and storage containers make it better i dont want it. My stuff all gets done here in cool damp leaves. Almost pure shade. I think most of my ways are wrong though.


A lid is just a way to regulate humidity and I’ve used individual domes before, but I had problems adjusting cuttings to ambient humidity levels when I removed the domes. I wrap my cuttings in parafilm which does the same thing. People with high ambient humidity do not need bins or parafilm.

When I do not wrap my cuttings in parafilm, I’ve had 100% losses whether done indoors or full shade outdoors. It’s all about your local conditions and what works for you.

This is why it’s useless to find the ‘best’ way as no one method works in all situations.

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On the subject of rooting… im going to try sand this coming week for some mulberry cuttings. Alot of folks say to use play sand, some say to use all purpose sand…then there is the sharp sand and coarse sand… confusing huh?

I am going to try two different sands for the sake of knowledge.

Mike’s Backyard Nursery has the best writeup i have seen on it… Mike worked at propagation houses for awhile and he stuck cuttings for a living. He propagates and sells things on his own now…so i trust that he knows what he is talking about.

He prefers silica sand.

After doing some homework i think i found it. $9 a bag and it says it contains silica on the bag.

He says not to use play sand… i agree. The play sand at the box stores are too fine. However i did see a different play sand at Wal-Mart… it looks and feels totally different. Its much coarser and has pebbles in it.

All Purpose Sand- this stuff at my box store looks like ground up concrete…its grayish black and seems to harden up.

Local Sand- i do have access to free local sand…which i plan on using as a control… i think if i used it exclusively and the cuttings failed i would wonder if the silica sand would have worked… and been mad.

I see lots and lots and lots of posts on social media of folks sticking cuttings in bags of top soil…also in cups of miracle grow potting mix… i have failed way too many times with those methods… roots dont need nutrients they just need moisture and a medium that will allow them to form roots. I think that an inert medium will make the roots grow more to search for nutrients…

thats where i am at with it.

Oh… i do want to stick a couple of cuttings in pine fines… that would be so much easier if that method works.

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Thank you. Unfortunately, I have an oil furnace blowing dry air. Even if I try setting up a humidifier before I go it won’t last very long before the air is dry enough to cause problems. The alternative is to enclose in clear totes that stay too wet. :sweat_smile: