A customer in Southwestern Colorado emailed me to tell me he was having problems getting seedlings to grow after they were sprouted. He reported that the first set of leaves were curling downward and growth seemed to have stopped. He had been watering with well water. The seeds were sprouted in Light Warrior soil under a T-5 fixture. I asked him for a photo of the problem which he promptly sent. Here's what they looked like:
You can see in the photos that the first true leaves and the cotyledons are purple in color. The newer foliage is a pale yellow-green that is fading to purple at the tips. From experience I know that the purpling is a sign of phosphorus lockout at high pH. The words "well water" are another clue that I keyed in on. Well water is notoriously high in alkaline so this was most likely the root cause.
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I asked the man to get a pH tester and measure his water. He emailed back that his water pH was above 8.0. Cannabis in soilless mixes do well within a pH range of 5.8 - 6.2, 6.0 being close to ideal. This was most certainly his problem.
There are two solutions I could think of: he could switch to bottled water or he could adjust the pH of his source water by adding citric acid. In order to reduce the alkalinity of his water to near-zero he would have to reduce the pH to 4.5. This is low enough to address the problem but not so acidic that it will harm his plants.
While this seedling may have suffered a significant setback, by successfully managing his pH it is very possible to bring it back to health and flower the plant successfully.
The hemp plant (Cannabis sativa) grows a long straight taproot from which many lateral roots are formed. This becomes apparent very quickly in standard 10x20 nursury plug trays which have become the defacto gear sold to cannabis gardeners. A typical 10x20 plug liner is about 2 inches deep and it doesn't take long for the tap root to begin twining around the plug cell. In just a short time the young seedlings become root bound. This shortens the time between waterings/feeds and leads to difficulties managing pH and moisture at the root zone.
The simplest fix is to sprout seeds in larger pots, but this can be a very inefficient use of what are often tight spaces.
I visit a lot of commercial nursery suppliers and am always looking for an improvement on 10x20 trays for rearing seedlings. The most interesting solution I have found is a product made for the forestry industry. Sometimes it's easy to forget that there are other crops out there with similar characteristics - like taproot shape - and that the mainstream horticulture industry has already solved problems related to those characteristics.
The individual plug cells are 2 inches in diameter and 7 inches in overall length. This makes them about 5 times the volume of a typical 72 cell plug liner cell. They are made of molded nursury plastic and fit in a molded plastic rack that holds up to 50 cells. The rack is slightly larger than a 10x20 tray so if you plan to fill up all 50 cells you'll need a bigger tray underneath to drain into.
The cells are easy to fill with potting mix and drain well through their bottoms. The wide collar above the tray is perfect for labeling with tape. These seedlings are an F2 generation of my Dakini Kush. The best of these are destined for my personal spring garden and I'm really looking forward to finishing them sinsemilla.
I have found the cells to be easy to water and that by lifting each cell I can gauge the weight and better judge when it's time to water. For watering/fertilizing seedlings I use a Nalgene wash bottle and feed from the top, allowing a small amount of excess to drain to waste. I performed a flush with large volumes of water through the cells and there was nothing difficult about that process.
I expect these to grow at least another two weeks before potting up, but when I do it will be a great opportunity to examine the roots for overall development and health. I'll post a photo of the roots once that's done.
I'm working on a simple increase of an Ethiopian Highland Sativa seed that was offered for sale by africanseeds.com on or about March 04, 2000. The ad copy on the website was a little "flowery" :) Here's the description from their archived website:
Ethiopian Highland- Outdoor/Indoor
Considered the finest in the world by the ruling Empress Zauditu and Ras Tafari who became the Emperor Haile Selassie this pure sativa comes direct from the ancient land of Ethiopia in what we believe is a world first. Cultivated and inbred by his latter day followers in the city of Shashemene this sativa grows well at altitude and in cooler climates. Buds typically long sativa with visible resin droplets providing a clear energetic high. Plants are shorter, branched and stockier than the tall bushy southern african types. Does well indoors especially behind glass.
| Flowering Period Outdoors - | 8-12 weeks (out)-(condition dependent) 8 weeks (in-behind glass) |
| Height | 1.5-2m(4.5-6ft) |
| Yields - Out | 10-15oz (3-500gms) |
| Yields - In | 1-2oz |
USD60 - 20 seeds
Like I said, it's a little over the top, but worth exploring.
This tiny sample came to me as part of a larger collection of heirloom landrace seed. I've never seen it offered for sale and I don't know of anyone who has grown it. I've searched the web for journals by growers who have grown and flowered this seed, but no luck. My goal is simply to increase the sample and to observe the life cycle of this particular genetic line. The following is a simple photo study of this project.
Germination was 100%. Considering these are between 7 and 12 years old, that's impressive.
Slightly more than half of the sprouted seeds have three cotyledons. Cannabis is naturally a dicotyledon. It should have only two.
The strain seems at home in my systems, although there was a little pH drift up to >6.5 in the early weeks. There were no leaf symptoms, but I did see a small amount of purple in the stems which may have been the beginning of a phosphorus deficiency.
The leaves are quite pinnate and beautifully formed.
The plants have all shown premordia under 18 hours of light at around 25 days. I've reduced the daylength to 16 hours to encourage flowering.
These are nearing 1 1/2ft in height and will be switched to a 12 hour day soon soon.
More as I have it.
UPDATE II: From the Westword Blog post 02/20/2012: "So, are seed sales banned? No, says Julie Postlethwait, spokeswoman for the MMED. But she admits that "it is a gray area. It is mentioned as being a form of medical marijuana. Technically they are allowed, but we have not yet defined how that would be."
The discussion has begun to take shape and I believe that we will reach an understanding on seed sales. This is all very good and will only serve to strengthen our state's laws surrounding cannabis and the seed from which it is grown. Hurray!
UPDATE: There seems to be a solution and I am moving as swiftly as possible to that end. If all goes well, we should come away stronger and better positioned than ever before. Stay tuned :)
I have very recently become aware of an action by the MMED wherein my seeds are not allowed for sale in the state's licensed dispensaries. This is a complete surprise to me and i have not yet been able to reach a representative of the DOR or MMED for clarification.
Due to this current development I am stopping all sales of seed until there can be some understanding with the powers that be.
Since the beginning of my efforts i have worked hard to set a good example of how a seed business should be conducted. I've set very high standards on germination, labeling, safety, quality and customer service. I hope this is the impression we have left with those who have supported us.
Regards,
Ben
Roughneck seed crop grown using Peter's 5-11-26, calcium nitrate and epsom salts. Flowered 63 days.
Click on a photo to see a larger version.
Earlier this year I had made an F2 gen of Roughneck (Jamaican Lambsbread x Purple Rhino). I never packaged the F2 seed because I had not tested it and didn't know how they would grow. Finally I got around to growing them out for selections. Here are a few flowers from those seeds:
Roughneck is a very fragrant, very resinous cultivar that is easy to grow. The form is quite compact, typically finishing under 5 feet in height. The plant produces a sturdy frame which serves it well in holding weight.
Putting your nose to these maturing flowers releases a delicious bouquet of concentrated floral and fruit notes, primarily apple, raisin, berry and hops. These plants are seeded which means that a good deal of the plant's energy is being expended on the developing seeds. Inspite of this, trichome and resin production are impressive.
Roughneck is a light/moderate feeder and grows best at modest fertilizer levels. Overfeeding, especially nitrogen, tends to produce excessive soft growth at the expense of flowering mass. I recommend continuous feeding at roughly 100 PPM nitrogen at pH of 6.1 - 6.5.
The selections for this seed crop are some of the best examples of Roughneck that I have seen so far. This crop will result in an F3 generation that, hopefully, will reflect the character and quality of these selections. i expect to harvest these in early January.
That's all I've got. -Ben
Ask ten commercial cannabis growers about their fertilizer formulations and you'll likely get ten very different answers. Some growers treat their recipes as closely held secrets, which is understandable considering that most commercial cannabis growers are self-taught and believe their methods to be superior to any others. In many cases, these growers' recipes are a complex combination of expensive hydro-store "nutes" plus a raft of poorly understood amendments and additives.
In short, the majority of cannabis growers rely on expensive, proprietary products with minimal information on the label. This approach amounts to nothing more than guesswork and a sort of praying at the altar of the hobby-level plant nutrition industry.
Because of the illegal nature of cannabis there is almost no credible information available on fertilization of this crop. To add to the confusion, in Colorado the USDA Extension program and its agents have been ordered not to help cannabis growers in any way, not to dispense advice and not to provide any support whatsoever. This is an unfortunate development and one that is highly prejudicial. So, with no available body of research on this crop and no assistance from the horticulture professionals, cannabis growers have few options but to buy and use these costly and hard to control inputs.
The following is a simple, safe and cost effective method of fertilizing indoor cannabis crops. It has been developed and tested over the last two years and has proven effective in growing healthy and productive plants. This method is based on EPA registered commercial fertilizers and amendments. These products are manufactured to very high tolerances and are considered by horticulture professionals to be very clean inputs. I hope that you find this information useful.
In the past when I have mentioned using commercial fertilizers to grow cannabis I have met with severe criticism. One Internet post referred to my use of these inputs as “disgusting” and “filthy”. There was no specific information given to back up these claims and one has to assume that it was simply push-back from an uninformed individual. The fact is that there is nothing contained in these compounds that the plants do not need or cannot assimilate. To put it more plainly, these are among the cleanest and highest quality plant fertilization products available anywhere on Earth.
The first step in developing and implementing any hydroponic fertilization formulation is to have your source water analyzed. Tests can be performed by a local municipal or commercial testing laboratory. The cost is minimal and the test results can save you significant time and money. What you are looking for is the amount of alkalinity and various ions present in your source water. Water with total alkalinity of less than 60 parts per million is ideal. Many municipal water sources along the the Front Range will meet this standard straight from the faucet.
In most commercial greenhouses, fertilizer concentrates are mixed in large batches and subsequently injected into irrigation water and fed on a continuous basis. This method works exceptionally well, is easy to implement and dramatically cuts both labor and fertilizer costs. In smaller gardens, fertilizers can be mixed at working strengths and applied directly at every watering.
Materials Needed:
Peters Professional 5-11-26 Hydroponic Special Water Soluble Fertilizer – sold in 25lb bags.
Yara Liva CALCINIT Solution Grade Calcium Nitrate – sold in 50lb bags.
Magnesium Sulphate or "Epsom Salts" – sold in 10lb, 25lb and 50lb bags.
For use with fertilizer injectors at 1:100 to make 100 gallons of working solution mix the following
Tank “A” Concentrate:
Peters Professional 5-11-26 Hydroponic Special Water Soluble Fertilizer 189.1 grams
Magnesium Sulphate or "Epsom Salts" 46.0 grams
water to make 1 gallon
Tank “B” Concentrate:
Yara Liva CALCINIT Solution Grade Calcium Nitrate 184.3 grams
water to make 1 gallon
Inject both “A” and “B” @ 1:100 to deliver PPM 100-24-108-92-25 (N-P-K-Ca-Mg)
To make a working strength solution mix the following:
Peters Professional 5-11-26 Hydroponic Special Water Soluble Fertilizer 1.89 grams/gallon
Magnesium Sulphate or "Epsom Salts" 0.46 grams/gallon
Yara Liva CALCINIT Solution Grade Calcium Nitrate 1.84 grams/gallon
Whether you are injecting or mixing as a working solution, these levels are suitable for use at every watering and are dilute enough not to cause accumulation of salts in the growing media, a common problem with dry salt fertilizers. The Peters 5-11-26 base mix contains pH buffers that when combined with low alkalinity water will deliver a solution with a pH between 6.0 and 6.3, which is ideal for cannabis crops.
I have run this formulation on numerous cannabis cultivars with great success. What's more, I have run the same formulation at all stages of growth from germination to vegetative growth to flower and finish. The results have been remarkable and I have encountered virtually no problems in my gardens.
As the US cannabis industry continues to evolve, one thing is certain: the most successful commercial growers will begin to adopt the very best methods and inputs from traditional mainstream horticulture.
Please direct any questions you may have regarding the contents of this article or the methods described to ben@centennialseeds.com
Ben Holmes
Founder
Centennial Seeds
Lafayette, CO
The purpose of this guide is to list and compare some of the more common seed germination methods used to sprout cannabis seed.
In order that a seed may germinate three things are required: proper temperature, moisture and oxygen.
Temperature: Fresh cannabis seed will sprout readily at temperatures between 70-80F. You may use a small lamp as a heat source or a seedling mat. It is important not to overheat seedlings or dry them out during germination.
Moisture: In most cases tap water can be used to germinate seeds. A good usable pH range is 5.8-6.2.
Oxygen: Seedlings need air to grow. Good grow media is said to "drain well" and allows for air spaces between the particles. Tiny roots grow into these spaces thus gaining access to oxygen and nutrients in the media.
Some media, particularly those used in hydroponic systems, necessitate that seedlings be established first in starter plugs like Rapid Rooters or Rockwool cubes.
To germinate seeds in Rockwool cubes, first soak the cubes in water adjusted to pH 5.5. Next, place a seed into the pre-drilled hole of the cube. Close the hole slightly by teasing the rockwool with a pointed tool. A toothpick works well for this. Place the cubes in a seedling tray and set the tray in a warm place. A humidity dome is not necessary to germinate seeds. Fresh seed should sprout within 1-4 days.
Common Difficulties: Rockwool is measurably alkaline and out of the package the pH is too high to germinate seed. Flush cubes well with 5.5 pH adjusted water and allow to drain. Do not squeeze the water out, just let it drip until it stops.
To germinate seeds in Rapid Rooter plugs, first soak the plugs in water adjusted to pH 6.0. Next, place a seed into the pre-formed hole. Close the hole slightly by tearing a tiny piece of the plug and using it to close the hole. Use only a bit and don't pack it into the hole. Place the plugs in a multi-cell propagation tray and set the tray in a warm place. A humidity dome is not necessary to germinate seeds. Fresh seed should sprout within 1-4 days.
Common Difficulties: Rapid rooters do not hold as much water as Rockwool cubes and they can dry out relatively quickly. Buy propagation trays with cell dimensions that allow your brand of starter plugs to fit loosely. This will allow a nice air gap between the plug and the cell walls and will promote strong, healthy roots.
To germinate seeds using the paper towel method, fold a full sheet paper towel (roughly 12"x11") into fourths. Hold the folded paper towel under running tap water until it is soaked. Hold the wet paper towel by a corner and allow it to drip until it stops. Lay the wet towel flat on a clean surface and open one layer of the folds like a book. Place the seeds on the sheet and fold it closed, two layers below the seeds, two layers above. Place the folded, wet paper towel containing the seeds inside a 1 quart Ziploc bag. Zip the bag closed and lay it flat on a warm surface. The top of a T5 fixture set to 16hrs on/8 hrs off works very well for this purpose. Fresh seed will often sprout within 24-36 hrs using this method.
Once the seeds have germinated and a white taproot has extended at least 1/4-1/2", the sprouts can then be gently transplanted to soil, starter plugs, RW cubes or whichever media you choose.
Common Difficulties: Using a paper towel that is too wet can starve the seeds of oxygen. One trick is to place a clean plastic water bottle cap inside the paper towel along with the seeds. The cap creates a tenting effect and allows the seeds contact with oxygen inside the bag.
Our Germination Method: We germinate seeds in Fafard Urban Mix "A" in plug trays, watered with tap water. We do not use a humidity dome or heating mats. Fafard Urban Mix "A" is a peat and perlite mix (peat/lite) and contains a light nutrient charge.
All of these methods will work. Each has their own advantages and disadvantages. We have found that the less handling a sprouted seed is exposed to, the higher the rate of success. If you have any questions you can write to me at info@centennialseeds.com
Just a quick post to show you a friend's outdoor garden. This is Waipi'o Hapa grown from seed, germinated April 1st and flowered outdoors in containers.
These are unpruned and growing in soil fed with, I believe, General Hydroponics fertilizers. I've seen this strain grown indoors by a number of different growers, including myself. I can't say I've ever seen Waipi'i Hapa plants this big and healthy.
Gardens like this one make me really appreciate how superior the sun is to artificial light and how much a difference environment makes in performance.
Just a quick update on the high CBD breeding project I am working on. The photos are taken at approximately 3-4 weeks flower.
The female parents were very resinous and quick to put on weight. The F1 plants seem to all have this same character.
I Like to see heavy gland coverage early in flower, especially along the petioles and the underside of leaves.
The plants have sturdy, straight frames with fairly open internode spacing. This seems to favor better flower development in the lower 2/3 of the plant.
I'm running these on Peters 5-11-26 @ 24 PPM P +calcium nitate and epsom salts.
The female parent stock tested very high for CBD with a relative THC content that was <CBD in all cases.
