starting cuttings in rockwool plugs in pots?

[KittenFishMom]

I bought "Gro|dan Macroplugs" rockwool plugs and pots for the plug to start cuttings in for my planted tank. I have searched the forum and found a lot of info about dealing with plants that arrived in rockwool, but I didn't find anything about starting cuttings in rockwool. 

Should I use rooting hormone before placing them in the plug? Will it hurt the fish? (I planned on setting them in tanks with fish as the plant's roots get started)

Should I put a ACO root tab in the rockwool with the cutting or wait until the roots start growing?

Any tips of tricks that would be good to know? 

Thanks

[gardenman]

I would not use rooting hormones. My "Schultz Take Root Rooting Hormone" has the following labeling. "Do not apply directly to water, to areas where surface water is present, or to intertidal areas below the mean high watermark. Do not contaminate water by cleaning of equipment or disposal of equipment wash waters." The "minimum PPE" I'm supposed to wear while using it includes a "long-sleeved shirt, long pants, shoes, socks, and chemical resistant or waterproof gloves." Bear in mind I don't wear most of that and I'm still alive after gardening and using rooting powders for most of my 63 years. Based on that labeling, I'm assuming it's not great stuff to be around.

If you have a willow tree in your yard/area, a few cuttings of that plopped into your aquarium might encourage more rooting, though most stem plants root like crazy with no help. If you Google "Willow Water" you can learn more about it. Willow Water has been used to root cuttings since the early American settler days. Odds are the willow branches will root themselves and then rip nitrates from your water faster than you can replace them, so once the cuttings have rooted, you'll probably want to remove the willows.

[KittenFishMom]

I am finally getting back to this project after several detours.

@gardenmanI don't have any willow growing near here. but I think the cuttings will root without it. I will try to get some willow in the spring.

The bag of rockwool recommend soaking the rockwool in water with the pH adjusted to 5.5.  It says I can use lemon juice, so that is my plan for the pH part. I also think I'll use part of a squirt of easy green.  (Squirt it in a cup, add water and pour part in the soaking water and put the rest in a fish tank.) 

I am then planning to put the cuttings in the rockwool in the pot in an active aquarium to get them growing.

Has anyone started cuttings using rockwool under water? Any tips, advice, or warning before I get underway on this project?

Thanks,

KittenFishMom

 

 

 

[Hobbit]

I haven’t started plants in rock wool, but I have left plants in their rockwool after bringing them home and… the rockwool eventually dissolved into a messy powder. 😞 I don’t know why that happened or how they keep that from happening in nurseries. But it’s something to be aware of.

[gardenman]

On 1/17/2022 at 9:16 AM, Hobbit said:

I haven’t started plants in rock wool, but I have left plants in their rockwool after bringing them home and… the rockwool eventually dissolved into a messy powder. 😞 I don’t know why that happened or how they keep that from happening in nurseries. But it’s something to be aware of.

Interesting, rock wool is often used in hydroponic systems because it won't break down or degrade. It's made much like fiberglass by melting rocks (essentially making lava) then spinning it into a fiberglass like material. It's typically made of basalt rock and chalk, so maybe your batch had more chalk than ideal? Chalk is a bit less water stable in acidic water.

Back to the willows for a second. If you want to try willow water and you've got a nearby florist, you can see if they have any Pussy Willow sprigs. They're a common cut flower option this time of year and are generally pretty low cost. They are a willow and will yield willow water. 

[KittenFishMom]

@Hobbit I would guess it might have to do with the pH in your water, but I don't know.

@gardenman Great idea about the pussy willows 

[Expectorating_Aubergine]

Yeah, willow water is magical! I've started cuttings in rockwool underwater. It went like if I had done it emersed. The only thing of note was to watch out for fish messing with it. I had a pleco that decided it liked the taste of the rock wool and at a bunch of it.

[KittenFishMom]

@Expectorating_Aubergine I saw a bluegill pick up a piece and shake it. I think it was looking for hiding scuds.

My crayfish and bullheads emptied every pot I planted this summer in my tank. I would plant seaweed in pebbles, and they would dig them out. I think the plants slowed the water enough for bits of food to settle into the pots. After a bit, I let them win and all plants floated.  I started sticking stem plants through ceramic bio filter rings, that has worked much better.

[JettsPapa]

I'm just now seeing this thread, but I start cuttings in rock wool frequently.  I don't think I've ever had one fail to root and grow.  I don't add any root tabs, just liquid fertilizer.