The Good Germin’: How To Germinate Old Weed Seeds And Bring Them Back To Life
Before there were marijuana clones and mother plants, there were marijuana seeds, the foundation of the cannabis industry. And here’s some big news for you: The price of quality marijuana seeds is going up while availability is going down.
If you were waiting to buy seeds of the famous, scintillating heritage or landrace marijuana strains we’ve been featuring, now’s the time. I’ve been tracking seed prices of quality strains sold by reliable cannabis seed resellers, and I’ve found that in the past year, prices have gone up an average of 30 percent.
Now, let’s talk about the challenge of germinating old, stale, or otherwise defective marijuana seeds.
No matter if you get your marijuana seeds from seeded buds (sometimes called bag seed), from seed resellers, from friends, or from dispensaries, seeds from different strains can show substantial variation in size and minor variation in shape. What you should be concerned about are seeds that don’t look like the seeds in the main photo accompanying this article.
Properly bred, dark-colored and patterned marijuana seeds like the ones in the above photo are seeds that by far possess the highest germination rate and produce plants with the most vitality and performance.
But if your cannabis seeds are pale, green, gray, shrunken, split, dried out, misshapen, poorly marked, or possess a hazy sheen (kind of like old wax that dried on a car before it could be buffed out), then those are defective cannabis seeds. Take a look at the below photo, which shows defective cannabis seeds that are far less likely to germinate.
Green, split seeds and seeds that aren’t properly shaped (mature cannabis seeds should look like miniature footballs) are immature seeds that didn’t fully ripen before the buds they were forming in were harvested. These seeds are a waste of your time.
Seed defects develop if your seeds have been stored improperly, or if the seeds are more than 4–5 years old. Also, if you get cannabis seeds from the less-reputable resellers, you might receive old or otherwise defective seeds. I’ve seen growers who eagerly awaited their seed order, only to be disappointed when they tore into seed packs to discover easily identifiable duds.
In many cases, the disreputable seed seller won’t refund the order or send a replacement order, and the would-be grower is left with a mixture of acceptable-looking seeds and defective ones.
Seeds that are grayish and sheeny are old seeds, and likely desiccated. Old seeds sometimes split or crack. If seeds of any shape are pale, light brown, gray, split, or cracked, they’re defective. But you may be able to salvage some of them so they grow out into plants that yield buds.
Tried And Tested Methods For Getting Old Seeds To Germinate. But Do These Methods Work?
Growers offer many tactics for germinating old seeds, and I’ve tried all their suggestions. I want to emphasize from the outset, if cannabis seeds are grossly immature, they’re unlikely to ever germinate, and it’s not worth trying to. For that reason, the following germination suggestions are for seeds that were allowed to mature and ripen fully before they were harvested.
Method 1: One of the most generic suggestions for germinating old, stale seeds is to soak them in reverse osmosis water pH adjusted to 6.1 for 24–48 hours, before placing the seeds into a rockwool cube, rapid rooter, peat pot or other germination media.
Result: I’ve seen no benefit from this suggestion.
Method 2: This one is rather extreme and time consuming. It involves scraping off the outer layer of the seed, sometimes including the shell itself, exposing the embryo and cotyledon, which are usually white, gray-white or greenish-white.
You then place the unshelled seed material into your regular germination media. Obviously, this is a severe tactic, and you shouldn’t expect it to work. But if the alternative is to not germinate the seeds at all, it’s worth a try anyway. If it doesn’t work, you’ve lost nothing. If it works, you’re a winner.
Result: It worked for me about 15 percent of the time I tried it on old seeds.
Method 3: Another radical tactic is to manually split one side of the seed shell, narrowly exposing the embryo and other internal material that is usually protected by the hard outer shell. The split seed is immediately placed in the usual germination media.
Result: My success rate for this tactic has also been about 15 percent.
Method 4: Over the years, I’ve seen companies offer “old seed soak kits” that allegedly contain special materials that stimulate old seeds to germinate. I contacted those companies and asked for third-party test data and ingredients information so I could ascertain if its products have any validity. Strange that the customer service reps refuse to provide information beyond vague, meaningless verbiage such as, “Our product contains bio-catalysts.”
They also refused to provide product samples. I have to tell you, if a hydroponics manufacturer or seeds producer isn’t confident enough in their products to provide samples for testing, this is an indication that their products are no good.
Result: Grower friends of mine bought several brands of “old seed soak” products and found them to be no more efficacious than soaking old seeds in pH-balanced reverse osmosis water, or just putting unsoaked old seeds into germination media.
If “seed soaker” products contain anything useful at all, it would likely be gibberellic acid, which has been used to treat marijuana seeds to induce germination, vitality and female gender.
Method 5: I’ve done experiments with stale, old seeds using a gibberellic acid pre-soak (i.e., adding gibberellic acid to get the soak solution to 100–150 parts per million), pH adjusted to 6.1, versus reverse osmosis water at pH 6.1.
Result: I had a marginally better germination rate from the gibberellic-treated seeds.
There are other experiments you can conduct if you have old seeds and you want to see if there’s any hope for them. Experiment with using seedling heat mats at a slightly higher temperature than for fresh marijuana seeds. Another tactic is to place the seeds less deep in germination media than you normally would, at about 1/4 inch (normal depth is about 1/2 inch).
You can try placing a T5 high-output fluorescent lamp over them even before they germinate, as if the light can coax them back from the dead like Jesus did with Lazarus.
Of all these methods, one thing’s for sure: Always use proper germination techniques, materials and procedures, regardless of the condition of your marijuana seeds.
Old Colombian Gold: After Germination, More Challenges
If old, stale seeds germinate at all, it usually happens several days after fresh seeds germinate. Expect fresh seeds to sprout 1–5 days after you start trying to generate them. But I’ve seen old, stale seeds that germinated after 13 days.
Even if you manage to coax defective seeds to germinate, you still have some challenges. Here’s an example of what I mean…
I had rare seeds given to me back in 2011. They were allegedly pure Colombian Gold genetics sourced from a lid of partially seeded buds in the early 1980s. Proper storage for cannabis seeds is in an airtight container in the non-freezer part of a refrigerator, and that’s where these had been since they were sourced.
The person who gave me the seeds said the last time he’d grown them was 2003. He had a 50 percent germination rate, but the strain was too difficult to grow outdoors where he lived due to climate conditions and because his locale’s high latitude is the wrong growing condition for a tropical sativa like Colombian Gold. After that failure, he put the remaining seeds back in the refrigerator and forgot about them.
I didn’t expect much from those old seeds. They were so tiny, about the size of a pinhead, and were pale gray, with that sad, dull sheen that characterizes old or dead cannabis seeds.
Still, Colombian Gold is a valuable strain and I had an indoor grow room I could easily control to give that rare heritage strain the environment it needed in which to thrive. I soaked the seeds for 24 hours in reverse osmosis water to which I’d added a very tiny amount of the vitamin B booster B-52, which is useful whenever you have stressed plants or seeds.
I planted 17 seeds about 1/4-inch deep in rockwool cubes and kept the seedling heat mat at 80°F. After five days, I saw no germination. But at day seven, one seedling popped its head above the cube, and by day 11 I had five Colombian Gold seedlings.
Five seedlings aren’t enough for a grow op, so I started fresh seeds of other sativa strains. Those seeds germinated in three days or fewer.
I measured performance of the Colombian Gold seedlings against the seedlings grown from fresh seeds. Two of the Colombian Gold seedlings were mutants — their early set of true leaves failed to develop properly, and the next sets showed the same mutation, so I terminated them.
One thing to expect from stale, old seeds: They often show mutations. Also, expect weak growth and dullness. The three remaining Colombian Gold seedlings popped their heads above the rockwool, developed 2–4 sets of normal leaves, then stalled.
As the seedlings from other strains gained height every day and their leaves grew larger, the Colombian Gold seedlings went into suspended animation. I tried giving them varying doses of light intensity and wavelength. I kept them on the seedling heat mat. After three weeks, when seedlings from fresh seeds were nearing a foot or more in height, only one Colombian Gold seedling had grown taller, but it was still several inches behind the fresh-seed seedlings.
I ended up keeping only one Colombian Gold female. It never had the vigor, root development, bud development, stalk sturdiness or harvest weight that fresh seeds of the same strain would have yielded.
This poor little female clearly lacked vitality from its earliest days, and generally plants grown from old seeds often have to be babied along. This means giving them extra doses of vitamin B, less light intensity than the other plants in the garden, more staking and other structural supports, more carbohydrates (like Bud Candy and Microbial Munch), and more potassium silicate (like Rhino Skin) to strengthen their weak stalks.
These compromised plants lack vigor, and may take longer to mature and develop in both grow phase and bloom phase. They might have hermaphroditic tendencies, weak stalks, insufficient root development, or be especially prone to spider mites, gray mold, pythium root rot and other attackers.
I had to baby that Colombian Gold, but she rewarded me with authentic sativa buds that were long, thin, and a beautiful golden color. The high was stellar and very 1970s-ish.
If the plant had been stronger and more vital, I would have kept it as a mother plant or waited until I had suitable male pollen before breeding her. But she was an experiment, the seed she came from had lain dormant for too long, so her adult life was feeble. I was lucky to get any nice buds from her at all.
Mind you, old and stale seeds aren’t always a dead end. I’ve had nine-year-old marijuana seeds that sprouted within seven days and grew out to be lovely, strong, heavyweight marijuana plants. And those seeds had been stored in a plastic bag inside a sock in a drawer in someone’s bedroom!
The message here is that if you have defective seeds that are immature, don’t waste time on them. But if you have old seeds, there’s little harm in trying the tactics I’ve discussed to see if you can grow out any of them. You might be able to get rare genetic treasure from old marijuana seeds, which makes it worth the effort to try to germinate them.
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Here’s How To Germinate Old Cannabis Seeds
Old cannabis seeds can be hard to germinate. Luckily, there are a few techniques that can help them sprout, even if they’ve been forgotten for some time.
Did you find some old seeds in a forgotten corner of the house? Well, you’re in luck; below we’ll share some simple tips to help you germinate old cannabis seeds.
BEFORE YOU START, SET YOUR EXPECTATIONS STRAIGHT
Before you start, it’s important you remember the following:
• Seeds can take a while to germinate. While healthy, fresh seeds can germinate in just a few days, old seeds can take anywhere from 2 days to 3 weeks to sprout. So be patient.
• Some seeds won’t germinate at all. Unfortunately, old seeds sometimes just don’t sprout. So, if you try all of the tips below and wait patiently without any luck, it’s likely your seeds are just too far gone.
TRY SCARRING YOUR SEEDS
One of the main reasons old cannabis seeds don’t germinate is because they tend to have a very hard outer shell. Now, cannabis seeds naturally have a hard shell that helps protect them until the conditions are right for them to germinate. Over time, however, this outer shell can become so hard that it inhibits the seed from germinating altogether.
To help older seeds along, it’s a good idea to try scarring them. To do so, simply line the inside of a matchbox with some fine sandpaper, place your seeds inside, and shake the box for a minute or so. This will help make some small cuts in the seeds’ outer shells to help them absorb some moisture.
If this isn’t enough, you can try carefully (and very gently) using a sharp knife like a Stanley blade to remove the ridge running along the middle of each seed. This should expose the inside of the seed a little, helping it absorb moisture and, hopefully, giving it a better chance of germinating.
TRY GERMINATING YOUR SEEDS IN CARBONATED WATER
Try dropping your old seeds into a glass of sparkling water. The CO₂ in the water should help the seeds absorb more moisture, encouraging them to sprout. You can also add some fulvic acid to the water to help break down the shell of your seeds. You’ll only need about 2.5ml of acid for a glass of sparkling water (roughly 250ml).
TRY “THE PAPER TOWEL METHOD”
This is a very popular way to germinate seeds. And for good reason; it’s pretty successful. Here’s how to germinate your cannabis seeds using paper towel:
1. Place 2 pieces of paper towel inside a salad plate.
2. Dampen the paper towels and place your seeds on top of it.
3. Cover the seeds with another 2 pieces of damp paper towel, then cover the salad plate with another plate, and keep it in a warm, dark cupboard.
4. Check on your seeds every 2–3 days.
LET MOTHER NATURE DO HER THING
Sometimes, it’s best to leave Mother Nature to work her magic on your old seeds. Try scarring your seeds a little as we showed you earlier, then let them sit in carbonated water overnight. Next, prepare a small nursery pot with some high-quality soil. Make a small hole in the middle of the pot with your finger, roughly the depth of your fingernail. Drop your seed inside the hole and cover it. Moisten the soil and keep your pot in a warm place with indirect sunlight—a windowsill works great.
REMEMBER TO STORE YOUR SEEDS PROPERLY
If you’ve tried all our tips above and still haven’t managed to germinate your seeds, it’s likely they are beyond the point of return. To avoid having the same problem next time, here are some tips to help you store your seeds:
• Seeds like cool, dry, and dark places.
• Quick changes in temperature and humidity are really bad for seeds. Try to keep them in a jar or other container to protect them against these environmental factors.
• Seeds don’t like light. Keep them in a dark place and avoid any unnecessary exposure.
• All of our seeds are vacuum-sealed. For the best germination rates, only open a pack of seeds when you’re ready to plant them.
5 Tips For Germinating Old Seeds
Here are some good tips for germinating seeds that are hard to start or are having trouble germinating. Have some patience though as it could take anywhere from three days to three weeks for a seed to germinate. Some of these tricks I would only use if the seed has not sprouted after two to three weeks or if you have a few seeds in reserve from a batch that haven’t germinated.
Seeds are comprised of an outer hard layer and an embryo which is inside the hard shell. The reason that older seeds don’t germinatem well is that the shell has become to hard and water is unable to penetrate, this process of imbibition is the start of the germination process. The seed will swell with water and eventually the shell will pop open and a small tap root will erupt.
One thing i wouldn’t do is to germinate your seeds on a paper towel. White paper is filled with bleach and other chemicals and is not a good thing for your plants. Use small jiffy starter blocks or a light soil:
1. Dilute 10ml (roughly one tsp) of Fulvic acid per litre (33 oz) of water.
2. Scuff the outer shell of the seed with some sand paper. Roll up a small cigar or sand paper or line a match box and gently shake the seeds over it. This will create micro abrasions letting in more water.
3. Use a lightly carbonated water. The extra Co2 will help the water penetrate the seed.
4. Use a light enzyme or seed booster, Plagron Nutrients has a very good one.
5. Finally if all else fails use an Exacto knife to slightly slice the seed open down the spine of the seed. This will make it easier for water to penetrate the shell.