Planting germinated cannabis seeds in rockwool remove wrapper

Help Starting Seeds In Rockwool

I am not sure I have done this right. I soaked the rockwool cubes for an hour in a nutrient mix. the mix was 1/2 gallon of water pH between 5 and 6 and 1/8 teaspoon of GH Micro and Gro. I put the seeds directly in 6 of them and in 4 of them I put seeds that i germinated on a paper towel. I then put the cubes in a big ziplock bag under lights 24hrs a day. My light setup is 4 4ft florescent tubes and 4 CFLs all 6000k. It has been a week and only one has sprouted and it was one of the seeds I didn’t germinate. Not what I expected.
My question is have I done this right or is there something I am missing? Also, when can I move the one that has sprouted to the hydroponic system?
Any help you guys can give me would be much appreciated.

ultimate procrastinator
Well-Known Member

I’m pretty sure you don’t want to have any sort of nutrients for seed propagation. Seeds only need their own food to sprout. Any extra may kill it.

nashvillekyle
Active Member
pnseekr
Active Member

Kyle. take some paper towels and dampen them and place on a saucer. Spread the seeds over it and cover with another damp towel and cover that with another saucer. Place in a warm (not hot) dark place and check on daily. Make sure paper towels stay damp (not soaked). Give them 4-5 days and they should pop. then place in rockwool. No nutes for a couple of weeks at least. Then add nutes 1/4 strength until you see good growth and add more a week at a time.

Hydrotech364
Well-Known Member

If I’ve said it once I’ve said it a thousand times,saying that nutes are bad for seedlings is like saying that a seed will not grow in fertile ground.
i soak my seeds in a mild nutrient solution in a folded cotton towel you can get at any auto parts there blue and you can find them in rolls pretty cheap.i put them in a metal tin and place it in my grow room under lights with lid on.my seeds are always sprouted within 48 hours with the majority sprouting in 24 hrs.you don’t have to leave the rock wool soaking.just splash them as this will leave more o2 in the cube.plant the seeds a lil over 3/8 of an inch in the cube.2 to 3 days later there up don’t water or re feed until the cubes get lighterthen you’re going good.i have also sat and sanded the sharp sides of the seeds with a fingernail file til there smooth ,this makes it easier on the seedling to split the hull and leaves less chance that the hull will be locked around the leaves of the seedling. Peace

ultimate procrastinator
Well-Known Member

I’ve read from a few places that using nutrients on seedling is very risky and if you do it should definately be less than 1/4 strength. And using nutrients to germinate? None of the germination guides I have read suggest using any kind of nutrients for that. Just water.

Hydrotech364
Well-Known Member

I have read that the sky is blue when its really just a reflection of the sea Marijuana is evolving so should the growers.

Str8y180
Active Member

on good advise i use clone FX seedling/cutting spray. Contains micro elements and vitamins for seed germination. Avoid full on grow nutes till about a week old.
To return to the original thread, why are you putting the rockwool cubes in ziplock bags dude? no wonder there not sprouting theres no fresh air. Use the zippy to germinate in wet paper towell then let em breathe in moist (not wet or soaked) rockwool cubes.

BLumen
Member

Just as a rule of thumb, never germinate with nutrients. Some say it works, and it may, but there is a risk. Why risk a process in a most fragile state of your plant’s lives? Would you give a newborn baby a T-Bone steak? Not unless you are retarded.

Get a small Tupperware container and add some pH friendly water to it. If you have a refrigerator or a water filter on your sink, this will make for a good, balanced pH for the most part. Just around 5.25-6 pH on the water alone will work best. Feel free to use distilled or bottled water, however you will soon find this to be like using Huggies brand diapers for a baby to shit in when the Kroger brand would contain the excrement just fine. Add the seeds you are intending to sprout into a folded up paper towel and place it in the bottom of the Tupperware container. Add the pH friendly water enough to soak the paper towel and have a couple of centimeters accumulated at the bottom of the container. Pop the lid on half way, leaving just a small crack for fresh air flow. Place in a dark place, such as a closet, and prop the container at a very slight angle so that the water will still keep the seeds wet but not completely submerged. Room temperature or slightly warmer will do just fine. Now, the hardest part is to leave them alone for about three days. The number one rule of growing next to keeping your mouth shut is to have patience. You can check them once or even twice a day if you must, lifting the paper towel to observe them and give them some fresh air. Just make sure to keep them in the dark as this will make the new plants search for the light they so desperately yearn for.

Once the sperm tails are finally showing, you know that you are almost ready. Place them back for 24 more hours and they are now good to go! Take out your Rockwool cubes and throw them in a bowl of the same pH friendly water. Leave them alone for a couple of hours to let them soak and become saturated. When you go back to pick them up, set them on a plate. Also, the paper around them can come off at this point if you are planning on placing them inside of some Hydrotron (Lecca/Clay Pellets) and net pots. They can go directly into the net pots like this, or you can leave the paper on for now and stack the cubes in rows on a tray that has a plastic cover and let them sprout there. When placing them on this tray, you may want to use enough perlite to cover the bottom of the container that the cubes will rest on, and just add a little water to moisten it up. This will keep perfect moisture and air underneath the cubes to support the root development, and they can keep this way for a longer time than if you did not use the perlite. Remember, do not add any nutrients at this point!

If you added the seedlings directly to the net pots or other medium in which they will develop, you will want to try and use some upside down plastic cups to act as a temporary greenhouse for moisture.

Be sure to mist or water the cubes lightly two to three times a day to keep them moist, and if you are using a Bubbleponics or other hydro system that distributes water into the net pots, just let it run this way with pure, clean water–no nutrients.

And there you have it. The seedlings can stay on the germination tray for a week or more if necessary, however it is best to get them into the net pots or growing medium once the roots are springing out of the bottoms of the cubes. Remove the paper from the cubes when you go to place them into your medium. If you are using net pots, do not add your 1/4 nutrient mixture to the water until roots are coming out of your net pot(s). This procedure will work every time if you have healthy seeds. Happy growing!

Yours truly,
BLumen

highpsi
Well-Known Member

With all due respect, some of you are unnecessarily complicating the germination issue. It’s really a simple matter. Wet (don’t soak) your medium with plain water (PH if necessary), poke your seeds into the medium about 1/4 inch deep so that the seed lays side on, then put them in a warm place (around 25*C), light isn’t necessary until the seedling actually pokes through the medium. You should see sprouts within 3 days. Always 100% successful for me.

The paper towel method certainly works as well, but you run the risk of damaging the delicate rootlet while transplanting into your medium. This is basically an unnecessary step unless you are running a breeding program or using old seeds that have a lower germination rate.

Germination needn’t be complicated. Could you imagine if farmers actually had to go though these steps to germinate their crops? They’d never get anything done!
http://www.mandalaseeds.com/html/germination.html
Here is a link to the best guide I’ve ever read on germination: http://www.mandalaseeds.com/html/germination.html

ol hippy
Well-Known Member

Just as a rule of thumb, never germinate with nutrients. Some say it works, and it may, but there is a risk. Why risk a process in a most fragile state of your plant’s lives? Would you give a newborn baby a T-Bone steak? Not unless you are retarded.

Get a small Tupperware container and add some pH friendly water to it. If you have a refrigerator or a water filter on your sink, this will make for a good, balanced pH for the most part. Just around 5.25-6 pH on the water alone will work best. Feel free to use distilled or bottled water, however you will soon find this to be like using Huggies brand diapers for a baby to shit in when the Kroger brand would contain the excrement just fine. Add the seeds you are intending to sprout into a folded up paper towel and place it in the bottom of the Tupperware container. Add the pH friendly water enough to soak the paper towel and have a couple of centimeters accumulated at the bottom of the container. Pop the lid on half way, leaving just a small crack for fresh air flow. Place in a dark place, such as a closet, and prop the container at a very slight angle so that the water will still keep the seeds wet but not completely submerged. Room temperature or slightly warmer will do just fine. Now, the hardest part is to leave them alone for about three days. The number one rule of growing next to keeping your mouth shut is to have patience. You can check them once or even twice a day if you must, lifting the paper towel to observe them and give them some fresh air. Just make sure to keep them in the dark as this will make the new plants search for the light they so desperately yearn for.

Once the sperm tails are finally showing, you know that you are almost ready. Place them back for 24 more hours and they are now good to go! Take out your Rockwool cubes and throw them in a bowl of the same pH friendly water. Leave them alone for a couple of hours to let them soak and become saturated. When you go back to pick them up, set them on a plate. Also, the paper around them can come off at this point if you are planning on placing them inside of some Hydrotron (Lecca/Clay Pellets) and net pots. They can go directly into the net pots like this, or you can leave the paper on for now and stack the cubes in rows on a tray that has a plastic cover and let them sprout there. When placing them on this tray, you may want to use enough perlite to cover the bottom of the container that the cubes will rest on, and just add a little water to moisten it up. This will keep perfect moisture and air underneath the cubes to support the root development, and they can keep this way for a longer time than if you did not use the perlite. Remember, do not add any nutrients at this point!

If you added the seedlings directly to the net pots or other medium in which they will develop, you will want to try and use some upside down plastic cups to act as a temporary greenhouse for moisture.

Be sure to mist or water the cubes lightly two to three times a day to keep them moist, and if you are using a Bubbleponics or other hydro system that distributes water into the net pots, just let it run this way with pure, clean water–no nutrients.

And there you have it. The seedlings can stay on the germination tray for a week or more if necessary, however it is best to get them into the net pots or growing medium once the roots are springing out of the bottoms of the cubes. Remove the paper from the cubes when you go to place them into your medium. If you are using net pots, do not add your 1/4 nutrient mixture to the water until roots are coming out of your net pot(s). This procedure will work every time if you have healthy seeds. Happy growing!

Yours truly,
BLumen

Nicely put !! I used my bubbleponic set up and dropped the seeds right in the damp rockwool cubes with the drip lines on them they popped in 48 hrs all six.

How to Germinate Cannabis Seeds

This article was co-authored by Lauren Kurtz. Lauren Kurtz is a Naturalist and Horticultural Specialist. Lauren has worked for Aurora, Colorado managing the Water-Wise Garden at Aurora Municipal Center for the Water Conservation Department. She earned a BA in Environmental and Sustainability Studies from Western Michigan University in 2014.

There are 10 references cited in this article, which can be found at the bottom of the page.

This article has been viewed 61,712 times.

Cannabis sativa sp. is commonly known as marijuana and has been grown throughout the world for thousands of years. Cannabis seeds germinate in 3 to 7 days, though some varieties may take 10 to 15 days. While germination is a natural process, factors such as light, humidity/moisture, and temperature must be controlled for cannabis seeds to sprout.

The Do’s and Don’ts of Rockwool

One of the most popular hydroponic growing mediums, rockwool has been used by growers for more than 40 years. Despite this lengthy history, there are still a few misconceptions as to how to use this substrate to maximum effect. Follow these guidelines to make the most of your rockwool.

Rockwool, sometimes referred to as stonewool, is a growing medium made of basalt melted back into lava and poured into a spinner in a process similar to making cotton candy.

Basalt is arguably one of the most abundant materials on Earth and a large percentage of these rocks are above sea level. Most rocks and soil above sea level originate from a combination of basalt and granite, which has a strikingly similar chemical composition to basalt.

As a growing medium, rockwool has been in use for more than 40 years and is one of the most commonly used substrates in commercial hydroponic productions across the world thanks to its inert properties, sterile start, and unique water-holding capacity.

The best growing performances can be achieved with rockwool, but like with most high-performance things, a few details have to be right for maximum effect. The following guidelines contain some of the most common do’s and don’ts to help you make the most of your rockwool.

Seed plugs made of rockwool. – Ferdiansyah Didi / Shutterstock

The Do’s of Rockwool

Do: Pre-soak Your Rockwool

Like most growing media, rockwool is shipped dry. There is 0% water in it when you buy it from the store. The initial wetting of rockwool, and actually all other media as well, is critical. Ideally, rockwool should be immersed in a nutrient solution adjusted to pH 5.5 until all the rising bubbles are gone.

This will allow the water to infiltrate the tiny pores in the product and prepare the entire volume to be colonized by roots. The immersion time depends on the size of the block in question, from just a few seconds for tiny seed plugs, to several minutes for the largest products.

In all cases, let the rockwool drain freely until water is no longer running out of it. Air will re-enter the largest pores, achieving the perfect balance between air and water in the medium. No squeezing or wringing is required.

Do: Keep the Wrap On Rockwool Cubes

Rockwool cubes, like most rockwool products are wrapped in an opaque plastic foil. This wrap has the same function as the walls of a plastic pot—it keeps the light out and the roots in. By covering the wool, it also prevents the growth of unsightly, yet harmless, algae.

In the case of rockwool slabs, where the wrap encases the product completely, it also aids the initial pre-soaking, as most slabs will not fit in buckets or tubs. Nutrient solution fills the wrap like a bag until the slab is thoroughly wet. Only after that stage should you cut a drainage slit in the slab’s wrapping.

It’s best to keep the plastic wrapping on your rockwool cubes. – AJCespedes / Shutterstock

Do: Always Fertilize Your Rockwool

Rockwool does not lock out any fertilizer. All the nutrients present in the block will be in the solution available to the plant or ready to drain out the bottom. This means whatever nutrients you use will have an immediate effect on the plant, and any feeding mistake can be immediately corrected, allowing you to optimize your fertilizer use.

If you irrigate with just water, the fertilizer concentration in the block will drop and may cause a slight shock to the plant. Rockwool has a tremendous capacity to retain water, so it is better to irrigate less often with a well-balanced nutrient mix than to water more frequently without the nutrients.

Read also:

Do: Allow for Sufficient Run-off

Plants always take up water at a higher rate than nutrients, so expect some increase in the concentration of fertilizer salts inside the medium between waterings. Furthermore, not all nutrients are taken up by the plant at the same rate, which creates nutrient imbalances and modifies the pH over time.

When the root zone is irrigated again, the water will push those nutrients down and replace them with the fresh nutrients it carries. If you never allow the substrate to drain sufficiently, the nutrients that were not consumed will accumulate in the medium, which may be unhealthy for your plants.

Allow 15-30% of the volume of liquid going in to drain out the bottom of the medium to maintain optimal nutritional conditions in the root zone. Rockwool is the fastest and easiest substrate for this, but this principle applies to all media.

Grower displaying roots of a cannabis plant grown in rockwool. – OpenRangeStock / Shutterstock

Do: Reuse and Recycle Rockwool

Although it is true that rockwool was originally manufactured as building insulation, horticultural rockwool shares few properties with the stuff that keeps your house warm in winter and cool in summer. Plants won’t grow in the insulation material because that material does not absorb water at all.

The fact that the two materials look similar has given rise to urban legends regarding reuse, toxicity and disposal. At the end of the plant life cycle, horticultural rockwool can be reused to grow different plants, or you can shred it to be composted and then reused in potting mixes or in garden beds.

Remember, rockwool is basalt, which is an excellent amendment for potted plants as crushed rock. Avoid using previously used rockwool to start plants, and also avoid reusing any growing media repeatedly to grow the same crop or crops within the same botanical family.

To prevent issues due to the presence of rotting roots, you can simply treat the used rockwool with enzymes. Your local hydroponics shop employees can help you with this.

Be careful not to squeeze your rockwool when handling. – Rendi Brahma / Shutterstock

The Don’ts of Rockwool

Don’t: Overwater Plants in Rockwool

Always fertilize the rockwool when you irrigate and allow for some drainage every time to wash off any excess fertilizer. The appropriate level of runoff should not exceed 30%, which means very little water should come out the bottom of a rockwool block.

If you are watering and the amount of drainage exceeds 30%, you are probably overwatering. This may lead to algae growth. Most of the water volume in rockwool—as much as 85%—is available water for the plant, and the block can dry down to very dry conditions before the plant finds itself in water stress (as low as 10% in rockwool). The plant can literally tip over because the block is too light before you need to water again.

Don’t: Squeeze Your Rockwool

A common myth is that excess water in rockwool should be removed by squeezing the block or plugs. Do not do this! The structure of the fibers in rockwool contain beneficial water retention and air porosity properties that allow root systems to develop.

Crushing the wool damages that structure and the air pockets that were initially present will never be restored. If rockwool is squeezed too much, the material will become a wet, soggy mess with no aeration whatsoever.

Bok choy seedlings at 8 days using rockwool. – Hideokun /Shutterstock

Don’t: Over-stack

Consider the structure and porosity of rockwool to determine how tall a rockwool container can be. Problems arise when irrigation is attempted from the bottom. Water is subject to gravity and will not sufficiently wick up more than 5-6-in. above the water surface, which actually applies to most media, leaving the top of the container dry and the bottom soaking wet.

All of the roots will be at the bottom of the block looking for the water and most of the media volume at the top of the container will be devoid of roots. Stacking rockwool products higher in ebb and flow systems is not a problem as long as irrigation is applied from the top. Water must travel through the network of fibers that constitutes the wool, so the container can be as tall as needed to get enough root volume to sustain a plant.

Don’t: Over-think

Growers have an emotional attachment to their plants. They love, baby, spoil, water and fertilize them. Some religiously measure electrical conductivity and pH daily, and obsessively check for growth. Well, don’t…or at least back down.

As mentioned earlier, rockwool has a huge water-holding capacity and all the fertilizer applied is available to the plant so it can often go for a long time without too much attention in the irrigation department.

Don’t believe the myth that rockwool affects the pH of the nutrient solution. It is actually the natural process of the plant removing nutrients that raises the pH. If the plants are growing actively and are healthy, don’t obsess about the pH. It’s easy to correct it by changing the feed solution, but the pH can fluctuate from 5-7.5 without any ill effect on the plants.

If you follow the guidelines in this article, you will find that rockwool is actually one of the easiest growing mediums to use. For more information, talk to the professionals at your local hydroponics shop. Happy growing!