robsamui
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Tropical Grow - suck it n see.
Before I began this project, I posted maybe a dozen messages on forums in Europe and America. I needed help and advice on how to grow herb in a humid tropical climate with more or less a year-round 12-12 spread of daylight. Nobody could help me. So I tried it the hard way and jumped in and did it, mistakes and all. I hope this backwards-look diary might help others with similar growing conditions.
I’m living in a tropical country, mid way between Vietnam and Malaysia. The average temperature is 30C degrees, but rising to 33C+ on warm days (85 – 92F) and the humidity is high, between 60 - 70% and with occasional highs of 90%. Added to which, six months of the year we have 12-12 daylight, and the other six months are 45 minutes plus or minus.
Four or five years ago, and knowing totally zip about growing herb, I bought some seeds, germinated them successfully, and watched them all wither on their 3rd set of leaves. I now think that the 12-12 daylight made them want to flower right away and so they just collapsed. But this year I decided to do it all properly. And I first spent three months solid reading everything I could find.
Firstly, using a light tent seemed the only practical way to control the quality and the amount of light. And so to the first problem: what size tent. I wanted a rapid turnover and to cash-in fast on maybe six or eight plants. But a big tent was out of the question. But a small tent means less plants. And that’s where my version of LST came in. The small 2x2x5-ft tent would go on its side, giving a practical floor area of 4 foot by 2, and the plants would be trained along the surface of the soil, in a circle, in low 9-inch pots. So I bought a tent from Aliexpress (PIC 1) for $130, and it was excellent.
But lighting was the biggest problem – this is the one thing that everybody is an expert about, and there is more religious ranting here than in the whole bible belt. Cost was the main thing – I didn't even know if anything was going to grow, never mind investing hundreds in stadium floodlighting.
And then it occurred to me that heat was going to be a bigger problem. The room temperature was going to be 30 degrees (85F) to begin with. And the coolest lights were CFLs. So that’s what I bought – from Aliexpress again, incuding one big 150W CFL for the middle. Plus a couple of full-spectrum (red bias) 45W LED cone-lights to balance things up. :volcano vaporizer: Plus, as an afterthought, a pair of T5 strip lights to hang along the front and rear of the whole length of the tent (PIC 2). Total wattage around 450 watts, including the three sets of fans.
Seeds? A bit of a lottery here. Something that would tolerate high temperatures. And definitely a feminised strain. I ended up with a basic kush (Pure Sensible Kush) and picked up a couple of others just as tests – compact and short-flowering times (Cotton Candy, Kera White Thunder). The idea was three months hit and run – but it didn't turn out that way!
Nutriments, minerals, soil acidity? Another area where everyone’s an expert. So I thought sod it – survival of the fittest – and bought bags of potting compost, and then mixed them with dry, crumbly buffalo sh*t and fragments of coconut husk to retain water (PIC 3).
The rainwater here is about as pure as you can get, so the PH level must be OK! (Which proved to be true . . .) Although I also bought-in some rose fertiliser pellets (15-5-15) and some high nitro stuff (10-52-17) for the budding stage.
The ‘pots’ I finally found in a supermarket – freezer storage, circular, 5-inches high and 9-inches diameter. I sprayed them black on the outside and drilled the bases for drain holes – plus the lids made perfect drip trays. But to begin with I germinated the seeds in fibre jiffy peat pellets, using one LED cone light and a pair of 45W 5600K CFL lights overhead (PIC 3 again). All the lighting was controlled from a simple 24-hour on-off timer, which worked faultlessly throughout. The seedlings took off like rockets, but looked leggy by their 4th leaves.
So I stopped guessing about light output and bought a lux-meter. The seedlings were getting 3,000 lumens so I doubled the number of CFLs and lowered them. This gave me around 7,000 lumens. And eventually, when all were growing well, I adjusted the lighting so the the minimum any plant got was 7K and the maximum was 9K. And I rotated the plants around every week to allow for this. But after 5 weeks something was wrong. The seedlings took about 3 weeks to shoot up to five leaves – then seemed to stick there (PIC 4).
And after another two weeks they were still on five or 6 leaves, although looking healthy enough (PIC 5).
Then I noticed that some of the plants were showing signs of heat stress. The problem is that when the ambient temperature is 33 degrees (90+F) any lights at all will only add their heat to this. Even with LEDs and CFLs, the temperatures in the open tent were sometimes 36C (98F) in the day, dropping down to around 30C (86F) at night. During the day there was a 6-inch fan blowing through an inlet vent, with a bank of four 4-inch computer fans inside the tent (PIC 6), plus a big room fan blowing into the tent. But without air-conditioning there was a problem.
This was solved by adding CO2 via 1-litre plastic bottles containing a sugar and yeast mix (PIC 4a).
Suddenly all the plants took off again and were growing almost an inch a day, as they should have been. But the end result was that I’d lost almost three weeks of growing – at 40 days I still had babies (PIC 5 again).
I had started to train the plants down towards the ground right from the start, using copper wire loops. Not only did this not corrode and chafe the stems, but it was easy to cut and bend. Now that the plants were growing well, once they got about half way around the edge of the pot I FIMmed half of them as an experiment (PIC 7).
This worked well, eventually causing good lateral growth (which later put out lots of buds – PIC 10).
And everything continued to do really well (apart from an attack of spider mites) right up until I put them into bud at around 120 days (PICS 8b and 8c). (Yep – the high temperatures had slowed them down.)
(The difference in colour is due to the warm daylight bulbs.)
I’d changed the lights to a set of warmer ones at around 3,600K (plus the LED cones) and put them onto a 12-12 cycle. To start with everything looked great, lots of buds forming. The buds came on thick and fast, but after a couple of weeks started to slow right down, just like what happened at the veggie stage. It seems that using CO2 doesn't have any effect when the plant is in bud.
But then I got caught out again. The other thing that constantly high temperatures cause is hermaphrodites. The kush was fine – no problem. But I didn't spot the male flowers forming on the Cotton Candy. Next time I’ll know to check each plant carefully as it starts to bud. But by the time I noticed this, it was too late. The little hairy things had already turned brown on most of the plants. But for some weird reason, one of the kush plants escaped this and went on to have no seeds . . .
About the third week of budding, everything slowed right down again and came almost to a halt. The trichomes were nice and cloudy (PIC 9), but the amount of buds on the colas weren't increasing – the gaps weren't filling in.
By this time it was about 150 days from germination and I was getting pissed off. I gave it another two weeks and then called it a day, harvesting two plants at a time, just to keep the others going (PICS 9a and 10).
The yield was poor, but potent (PIC 11). I only got about ¼ ounce from each plant (five plants after I culled the herms), but bear in mind that the plants would only have been about 20-24 inches high (but bushy) if they had been allowed to grow naturally(PIC 10 again). This was my plan anyway, but I was expecting it to all have happened in less than half the time!
Final problem – ever tried curing pulled plants in a tropical climate with 70-80% humidity? My idea was this – a black plastic 10 gallon bin with a mesh waste-paper basket inside – plus some big sacks of silica gel at the bottom (PIC 12a and 12b).
But on the third day I could see signs of mold forming. So the answer was to hang a 60W tungsten bulb in the middle. It worked fine, slowly letting them dry out over a period of about two weeks. And then finally finishing them off by stripping the buds and laying them on the bottom of the the waste-paper basket with the bulb about 10 inches above.
I've learned a lot. I’m going to leave the next grow until the weather cools down, between mid-October and January, when the average temp here is 26 - 30 C (78 - 85F). I’m going to buy feminised auto kush seeds to start with, so I don’t have to mess about with opening the tent for ventilation at 6.45 each morning. And I’m going to grow two plants in each bowl, to maximise the yield.
And hopefully, this time around, I’ll end up with 14 mini-plants in three months, each with at least half an ounce of bud on them. Keep your fingers crossed for me, and if you've got any advice, it’s welcome!
Before I began this project, I posted maybe a dozen messages on forums in Europe and America. I needed help and advice on how to grow herb in a humid tropical climate with more or less a year-round 12-12 spread of daylight. Nobody could help me. So I tried it the hard way and jumped in and did it, mistakes and all. I hope this backwards-look diary might help others with similar growing conditions.
I’m living in a tropical country, mid way between Vietnam and Malaysia. The average temperature is 30C degrees, but rising to 33C+ on warm days (85 – 92F) and the humidity is high, between 60 - 70% and with occasional highs of 90%. Added to which, six months of the year we have 12-12 daylight, and the other six months are 45 minutes plus or minus.
Four or five years ago, and knowing totally zip about growing herb, I bought some seeds, germinated them successfully, and watched them all wither on their 3rd set of leaves. I now think that the 12-12 daylight made them want to flower right away and so they just collapsed. But this year I decided to do it all properly. And I first spent three months solid reading everything I could find.
Firstly, using a light tent seemed the only practical way to control the quality and the amount of light. And so to the first problem: what size tent. I wanted a rapid turnover and to cash-in fast on maybe six or eight plants. But a big tent was out of the question. But a small tent means less plants. And that’s where my version of LST came in. The small 2x2x5-ft tent would go on its side, giving a practical floor area of 4 foot by 2, and the plants would be trained along the surface of the soil, in a circle, in low 9-inch pots. So I bought a tent from Aliexpress (PIC 1) for $130, and it was excellent.
But lighting was the biggest problem – this is the one thing that everybody is an expert about, and there is more religious ranting here than in the whole bible belt. Cost was the main thing – I didn't even know if anything was going to grow, never mind investing hundreds in stadium floodlighting.
And then it occurred to me that heat was going to be a bigger problem. The room temperature was going to be 30 degrees (85F) to begin with. And the coolest lights were CFLs. So that’s what I bought – from Aliexpress again, incuding one big 150W CFL for the middle. Plus a couple of full-spectrum (red bias) 45W LED cone-lights to balance things up. :volcano vaporizer: Plus, as an afterthought, a pair of T5 strip lights to hang along the front and rear of the whole length of the tent (PIC 2). Total wattage around 450 watts, including the three sets of fans.
Seeds? A bit of a lottery here. Something that would tolerate high temperatures. And definitely a feminised strain. I ended up with a basic kush (Pure Sensible Kush) and picked up a couple of others just as tests – compact and short-flowering times (Cotton Candy, Kera White Thunder). The idea was three months hit and run – but it didn't turn out that way!
Nutriments, minerals, soil acidity? Another area where everyone’s an expert. So I thought sod it – survival of the fittest – and bought bags of potting compost, and then mixed them with dry, crumbly buffalo sh*t and fragments of coconut husk to retain water (PIC 3).
The rainwater here is about as pure as you can get, so the PH level must be OK! (Which proved to be true . . .) Although I also bought-in some rose fertiliser pellets (15-5-15) and some high nitro stuff (10-52-17) for the budding stage.
The ‘pots’ I finally found in a supermarket – freezer storage, circular, 5-inches high and 9-inches diameter. I sprayed them black on the outside and drilled the bases for drain holes – plus the lids made perfect drip trays. But to begin with I germinated the seeds in fibre jiffy peat pellets, using one LED cone light and a pair of 45W 5600K CFL lights overhead (PIC 3 again). All the lighting was controlled from a simple 24-hour on-off timer, which worked faultlessly throughout. The seedlings took off like rockets, but looked leggy by their 4th leaves.
So I stopped guessing about light output and bought a lux-meter. The seedlings were getting 3,000 lumens so I doubled the number of CFLs and lowered them. This gave me around 7,000 lumens. And eventually, when all were growing well, I adjusted the lighting so the the minimum any plant got was 7K and the maximum was 9K. And I rotated the plants around every week to allow for this. But after 5 weeks something was wrong. The seedlings took about 3 weeks to shoot up to five leaves – then seemed to stick there (PIC 4).
And after another two weeks they were still on five or 6 leaves, although looking healthy enough (PIC 5).
Then I noticed that some of the plants were showing signs of heat stress. The problem is that when the ambient temperature is 33 degrees (90+F) any lights at all will only add their heat to this. Even with LEDs and CFLs, the temperatures in the open tent were sometimes 36C (98F) in the day, dropping down to around 30C (86F) at night. During the day there was a 6-inch fan blowing through an inlet vent, with a bank of four 4-inch computer fans inside the tent (PIC 6), plus a big room fan blowing into the tent. But without air-conditioning there was a problem.
This was solved by adding CO2 via 1-litre plastic bottles containing a sugar and yeast mix (PIC 4a).
Suddenly all the plants took off again and were growing almost an inch a day, as they should have been. But the end result was that I’d lost almost three weeks of growing – at 40 days I still had babies (PIC 5 again).
I had started to train the plants down towards the ground right from the start, using copper wire loops. Not only did this not corrode and chafe the stems, but it was easy to cut and bend. Now that the plants were growing well, once they got about half way around the edge of the pot I FIMmed half of them as an experiment (PIC 7).
This worked well, eventually causing good lateral growth (which later put out lots of buds – PIC 10).
And everything continued to do really well (apart from an attack of spider mites) right up until I put them into bud at around 120 days (PICS 8b and 8c). (Yep – the high temperatures had slowed them down.)
(The difference in colour is due to the warm daylight bulbs.)
I’d changed the lights to a set of warmer ones at around 3,600K (plus the LED cones) and put them onto a 12-12 cycle. To start with everything looked great, lots of buds forming. The buds came on thick and fast, but after a couple of weeks started to slow right down, just like what happened at the veggie stage. It seems that using CO2 doesn't have any effect when the plant is in bud.
But then I got caught out again. The other thing that constantly high temperatures cause is hermaphrodites. The kush was fine – no problem. But I didn't spot the male flowers forming on the Cotton Candy. Next time I’ll know to check each plant carefully as it starts to bud. But by the time I noticed this, it was too late. The little hairy things had already turned brown on most of the plants. But for some weird reason, one of the kush plants escaped this and went on to have no seeds . . .
About the third week of budding, everything slowed right down again and came almost to a halt. The trichomes were nice and cloudy (PIC 9), but the amount of buds on the colas weren't increasing – the gaps weren't filling in.
By this time it was about 150 days from germination and I was getting pissed off. I gave it another two weeks and then called it a day, harvesting two plants at a time, just to keep the others going (PICS 9a and 10).
The yield was poor, but potent (PIC 11). I only got about ¼ ounce from each plant (five plants after I culled the herms), but bear in mind that the plants would only have been about 20-24 inches high (but bushy) if they had been allowed to grow naturally(PIC 10 again). This was my plan anyway, but I was expecting it to all have happened in less than half the time!
Final problem – ever tried curing pulled plants in a tropical climate with 70-80% humidity? My idea was this – a black plastic 10 gallon bin with a mesh waste-paper basket inside – plus some big sacks of silica gel at the bottom (PIC 12a and 12b).
But on the third day I could see signs of mold forming. So the answer was to hang a 60W tungsten bulb in the middle. It worked fine, slowly letting them dry out over a period of about two weeks. And then finally finishing them off by stripping the buds and laying them on the bottom of the the waste-paper basket with the bulb about 10 inches above.
I've learned a lot. I’m going to leave the next grow until the weather cools down, between mid-October and January, when the average temp here is 26 - 30 C (78 - 85F). I’m going to buy feminised auto kush seeds to start with, so I don’t have to mess about with opening the tent for ventilation at 6.45 each morning. And I’m going to grow two plants in each bowl, to maximise the yield.
And hopefully, this time around, I’ll end up with 14 mini-plants in three months, each with at least half an ounce of bud on them. Keep your fingers crossed for me, and if you've got any advice, it’s welcome!
