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weed seeds in rockwool cubes

Best way starting seeds in rockwool?

Hey i really do need a BEST advice how to start my uniq seeds in high success rate! Some of my seeds may be damaged over years, but i need to try to save them!

Strains,
Whitewidow x Euforia x "Mindfuck".
Ghost of Ghana 100% equatorial sativa. (special).
Food of Gods secret strain from village of south Africa! (special).

Professional advice = reputation+

Charlie Green
Well-Known Member
Humboldt14
Well-Known Member

germinate them them move them to the rock wool cubes

Charlie Green
Well-Known Member

germinate them them move them to the rock wool cubes

Humboldt14
Well-Known Member

germinate them what ever method you prefer to use,

I use the paper towel method 100 percent success rate for me, then once the little white tail pops out of the seed, then move the seeds to the 1 inch rock wool with the tail facing down in the hole then lightly put a little piece of rock wool over the hole that the seed is in.

Dirty Harry
Well-Known Member
Humboldt14
Well-Known Member

you dont use a humidity dome for starting seeds and second rockwool cubes will not dry out. they retain allot of water, and with

seedlings in them you would not have to water for about a week maybe longer.

i have a Hydro set up also so i have been starting seedlings in rockwool for years.

Dirty Harry
Well-Known Member

you dont use a humidity dome for starting seeds and second rockwool cubes will not dry out. they retain allot of water, and with

seedlings in them you would not have to water for about a week maybe longer.

i have a Hydro set up also so i have been starting seedlings in rockwool for years.

Charlie Green
Well-Known Member
ganicsarebetter
Well-Known Member

germinate in paper towl folded up, leave a littel pocket, and moisten the paper towe, and keep moist. leave it in a tupperware contaier in the dark for 3-7 days, keeping the towel moist, and you should see the embryo.

another ethod that ive HEARD works is just to put in a shotglass over night, see what happens ins the seed absorbs the moisture until it pops. thats what ya want..

the paper towel method ALWAYS works. IMO

Dwezelitsame
Well-Known Member

i would have soaked mine over night first 75 percent of time is split the next day

from there go to paper towel all in dark on heating pad at about 80 degrees

once split i transfer to cup with holes in bottom covered with a baggie and rubber band for a little greenhouse effect once soil break i remove plastic once again all heating pad .. i normally use heating pad until first transplant at 3 or 4 weeks old

Fuzzbutter
Active Member

Pre-sprout your seeds in a moist paper towel and then plant in the rock wool once the spouts are over 1/2" I did this and got 14/20 sprouted from which I had to pick 7 and they are all doing AMAZING.

It’s easy:
get 2 paper towels
fold them in half together
place the seeds in-between the folded area
dampen the paper towel (damp, not dripping, but not too dry either)
place the damp paper towel with seeds in a ziploc bag
put them somewhere dark for a couple days
ta-da!

Also, rock wool is naturally alkaline, so you’ll need to soak it in PH balanced water over night first before putting ANYTHING in it. My plants are currently in rock wool and doing great

Fuzzbutter
Active Member

you dont use a humidity dome for starting seeds and second rockwool cubes will not dry out. they retain allot of water, and with

seedlings in them you would not have to water for about a week maybe longer.

i have a Hydro set up also so i have been starting seedlings in rockwool for years.

Serapis
Well-Known Member

I don’t know where the paper towel method started, I only know that it has been around far too long. I first learned of it over 30 years ago. It’s hogwash. does it work? Most of the time, but why risk handling a delicate seed and it’s new born tap root when you can simply place the seed in any moist medium and have it germinate? If the seed germinates in a paper towel, which surely can’t sustain the seed, won’t it surely germinate in moist rockwool?

Please don’t tell me God created weed that needed man’s assistance to sustain it’s self because there is no paper towels laying around in mother nature. LOL I’m sorry, but I have to laugh at the though of all the extra work towlies have to go through. Just plant the seed already, if it’s viable, it will grow, because amazingly, it is a weed. It’s hardy. The only time the plant has troubles is when we try to care for them.

Hydroponic Growing Mediums: How to Plant into Rockwool Cubes

Pros and Cons of Using Rockwool Cubes as a growing medium

Pros of growing in Rockwool cubes

  • Sterile medium for cloning
  • Good drainage
  • Excellent for seed germination
  • Can use any nutrient solution
  • Easy to transplant
  • Easy for roots to penetrate
  • Can be added to compost

Cons of Rockwool cubes as a hydroponic growing medium

  • Naturally High pH
  • Not sustainable
  • Not biodegradable
  • Potentially dangerous to human health
  • Grows surface algae

What is a Rockwool cube made of?

Rockwool cubes are made from chalk and the basalt rock that is formed by volcanoes, heated to a high degree (3000 ℉ ) of heat then spun and cooled. Next, a binder is added and the substrate is flattened to form a sheet. Rockwool is often sold as a hydroponic growing medium in granulate mini blocks, starter plugs, cubes, and slabs. Their dense structure promotes strong root development making it ideal for seed starting in a hydroponic system. Although Rockwool is made from natural materials, the process is not natural making the substrate unsustainable, energy-intensive, and not biodegradable.

The physical properties and harmful chemicals of Rockwool cause skin, eye, and lung irritation and have been linked to long-term health concerns. ( Environmental Protection Agency lists it as a “Group 2B” material)

Are Rockwool cubes good for cloning?

Rockwool is a sterile, manufactured substrate containing no pests, weed seeds, or diseases making it a common choice for cloning plants in a sterile environment. This also means that it contains no beneficial fungi or nutrients. This is ideal for those wanting to retain full control of their nutrient solution and regimen.

When cloning in any soilless media it is important to maintain humidity with a humidity dome throughout the rooting process. We recommend using our 6” tall humidity domes to provide growing space and ideal conditions for new seedlings and stem cuttings.

Hydroponic Gardening with Rockwool

Seed Starting Using Rockwool Cubes

Seeds are easy to plant in the 2 inch Rockwool cubes that fit inside the Bootstrap Farmer 32-cell insert tray. These typically have an indentation in the center for the seed or seeds. For smaller seeds, dip a moistened toothpick into your seeds to pick up one or two. Insert the toothpick into the indentation and twist it against the side of the hole to release the seeds.

Once all of the cells have been planted, ensure that the media is evenly moist and place under a blackout dome until the majority of the seeds have sprouted.

Planting clones in Rockwool cubes

Planting softwood clones in mineral wool work very well because of the moisture-retaining properties. When a new cutting is starting to form root buds, drying out could send the cutting back into survival mode instead of new plant development. To plant clones, use sterile equipment to take a stem cutting from the mother plant. Dip the end of each stem cutting into rooting hormone, honey, or aloe powder to protect it from bacteria. Push the cutting into the cube at least an inch deep but not through to the bottom.

The cubes can then be placed into a tray with holes or one of these mesh tray sets for the rooting period. The mesh tray will allow for easy bottom watering with the 1020 deep tray while the humidity dome will ensure proper moisture levels until roots have formed. Place the entire 1020 on a heat mat with a thermostatand keep between 70℉ and 80℉ until root growth is established.

What can I use instead of Rockwool cubes?

Sterile growing media like ProMix , soil blocks, coco coir , hemp mats , clay pellets, decomposed granite, perlite, vermiculite, peat moss, and potting soil are all viable alternatives to using a Rockwool slab or cube for starting seeds, planting, and cloning.

How often should you water seedlings in Rockwool?

Rockwool is very good at holding moisture. Its superior water retention abilities make it ideal for delicate new growth. Plants growing in Rockwool can handle daily waterings. The material of the Rockwool also allows excellent air circulation, making overwatering difficult. This makes it an ideal substrate for hydroponic techniques. Rock wool cubes are often planted into 32 cell trays and watered in a flood and drain system like this automated grow rack .

What is the pH of Rockwool?

Rockwool tends to be too basic for most plants that prefer acidic soil conditions. With a pH between 7 and 8, you must presoak Rockwool in a slightly acidic solution (pH 5.5 to 6.5) for at least an hour before use. This can be done by adding several drops of lemon juice or pH down to the water, using pH test strips to attain the correct acidity. Once in use, you need to pay attention to the pH as it can quickly shift. This is why many prefer to use coco coir instead of Rockwool.

Can I put Rockwool in my compost?

While Rockwool or any type of mineral wool is not biodegradable it can be added to compost in order to add drainage and eventual mineral content to the resulting soil. If you plan to add your used Rockwool cubes to your compost bin you will want to shred them as much as possible before mixing them in. Left whole they can persist in the soil indefinitely because mineral wools do not contain any organic matter.

Reusing Rockwool

Some growers choose to reuse Rockwool although it is not recommended because once the cubes are full of roots they can begin to harbor mold, fungus, and detrimental bacteria. If you do choose to reuse your cubes, allow the roots inside to dry completely and then sterilize them by submerging them in boiling water for at least 10 minutes. For more information on proper equipment, cleaning check out this article on How to Wash and Care for Seedling Trays.

Rockwool can be a great tool for hydroponics, cloning, and seed starting. While it does come with some limitations, it can be the perfect substrate for certain applications. For more information on ways, growers and gardeners alike start their seeds indoors, check out Seed Starting: 101 Starting Seeds Indoors For Your Garden.