I do a couple things to get my plants to finish when I want them to. First off, I start with a high EC in veg (keep in mind I am a bottle grower, who uses some organic inputs, mostly recharge mammoth p and insect frass). By high I mean 2.5 or so (1250 ppm x 500). I maintain that from the time the clone is transplanted until I flip into flower. Following flip I start to reduce the EC somewhat, I would go from 2.5 down to about 2.1 (1050), I maintain this level for about 10 days then I reduce again down to about 1.9 (950pm) for about a week. Once I am around day 21 I start to really pay attention to my runoff EC. If I am seeing like 2.8-3.0 EC or higher I will back down on my next feed heavily to about .9-1.1 EC (450-550ppm) for 1 or 2 feeds. I will do this until I see my EC at a reasonable level for this age of growth which I would like to target about 1.9 or lower. So from day 21-28 if runoff is at a tolerable level then I will be feeding in around 1.5-1.6 EC until I start adding PK. When the PK comes in around day 28 or so I try to target around 1.3 EC (650ppm) for a week. I need to make a disclaimer that I am not only watching the EC runoff but I am also watching the color of the plants. To have this work you really need to be dialed into your environment in your grow with the proper environment you will see the proper coloration and plant growth. So if I am seeing very heavy green lush plants I know I can dial back some, if my plants are lighter green or boarder on some yellow I know they are not getting enough food and might need more. These are things I keep in mind from day 1-35 or so. Once I start getting into 35-40 and wanting my plants to finish say like day 63 then I will want the lighter green to start to show.

So now we are in say day 35, I am continuing my PK boosted feed at around 1.3 ec until day 40 or so. I should mention too, I am gradually decreesing my temps 1 degree day time at a time but I will come back to temps. My hope is at around day 40 that my runoff ec will be lower than 1.8 or 900ppm, I really want to see this number start to come down. If it isnt dropping during the pk time I might run a feed or 2 at as low as .6 ec (thats right as low as about 290ppm so I am bascially adding 2ml calmag 2ml base 1 ml pk per gal). This to me acts like a flush and reduces the amount of EC in the media but at the same time still feeding my plants. It may seem like a flush but there is enough nutrition in there to allow the plants to eat. So now, we are at day 40, I cut pk and then reduce the ec again. For me I already know how long I want to go and around the date I want to harvest. If I am running something with a longer flowering time like day 70 (for instance GMO) I will keep my ec around 1.1-1.2 for a few extra feeds. If I am looking to finish with a shorter flowering time, say day 63, then I would reduce my ec at this time to around .9 for a feed or 2 (depending on my runoff numbers), if my runoff numbers are way to high and my plants still green I would make that number be .6ec. My last 2-3 actual feedings I want to be around 2ml cal mag 2 ml base and come in around .6 ec until I am about 18 days from harvest. For me, and this doesnt go for everyone, I want to hit with Winter Frost 18 days out from harvest (give or take a couple days), 1 time at 10/ml per gal. After that I am on straight water. This is how I gradually reduce my feeds to achieve a properly flushed and finished plant. Do I think this lowers my yield? I will be honest, I feeding like this commercially for about 2 years before I was forced to try Athena. Our weight output ranged from roughly 2.5lb/light to at the highest it was around 3.4 per light, remember commercial enviorment with everything dialed in.

Once I was forced to switch to Athena we ran at a consistent ec of 3.0ec through day 21 of flower then reduced to 2.0 ec until flush. Our yields did go up at this point, our highest was bout 3.7lb/light, but to me that flower was not nearly as good as it was before. I am not trying to push my plants to the absolute max, and thats what the Athena is doing at such high EC. The amount of salt built up on the bottom of the pots where runoff comes out, and the amount of salt left over on the tables were unappealing to me. So can you get more out of your plants feeding more later in the cycle, sure, but is it worth it? Thats a question for you to answer. I like to keep in mind an old DGC name, less is more. Sometimes our plants do so much better by giving it a little bit less, whether that be light or food.

Its important to note that I have close to 200 harvests under my belt. That means I have gone through a lot of trial and error, I have made a ton of mistakes, but I keep learning and I keep listening, and by listening I mean I am hearing what the plants are telling me. The plants talk to us and tell us so much, and for that we need to listen.

Ok now let me get into temps a little bit. Something I do not hear talked about enough is leaf surface temperature. In most cases it is indicative to what the temp is in the room, however there are some cases where it a little more or less then what the room temp is. For sake of explanation I am going to focus on room temps for this discussion. Environment is the number 1 factor when dialing in a grow room. If your environment isn’t right and dialed its hard to diagnose problems, and to have a fully healthy plant explode with growth. Thats why whenever someone posts something I always ask first, where is your environment? I would like to coin the phrase, you cannot grow a healthy plant without a healthy room. And to have a healthy room, follow VPD!!!! Ok so, here are my optimal ranges of VPD, and if you dont know go to pulsegrows website and follow their charts for plant growth in certain phases. For clones, I want to be in the .4-.6 kPa range, so very high humilities. Once transplanted I want to be in the range of about .8 kPa, so if we are running a room around 81 degrees in veg I would want my humidity levels to be at about 70%. I maintain this through veg and into the first couple days of flip. By day 8 or so I want to reduce my humidity a little and hit around .9 kPa or so keeping the same temp, So now I am at about 65% humidity. Its around day 18 or so I make my first drop in temp to about 80, only dropping daytime temps about 1 degree. Its important to note, think of the day you flip into flower as like the 2nd or 3rd week in August. No matter where you live typically the temps start to reduce slightly as the seasons progress. So around day 18 im thinking is similar to the first week of September. Not as hot as July and August and night time temps starting to fall somewhat. So an 80 degree day I would set my night time up around 76 or so. Once I am into the mid to late day 20’s I drop day and night another degree.

So 79-74/75. Again around day 35 so I am at 78 day 73/74 night. 40 days from flip then would put us around what would be October outdoors. Cooler daytime temps, cooler night time temps. I would set myself up to still boarder maybe 78 during the day but more like 77. This time of year night time drops a little more. So now I am looking to be around 70 degrees or so at night. Now, once I get into flush and am in my final 2 weeks or so I would carry my temps around 77 daytime and 68-69 night time. I really dont want to dip below 68 unless im 1000% certain I can bring down my humidity too. The last week of flower if I am really trying to get a heavy fade I might go down to 76 during the day. Ok, so I have skipped some important details that I cannot leave out. Lets switch back to VPD, if I am at .9 the first week of flower I am at 1.1-1.0 by day 14-18, this would put me at temps around 80 and humidity around 60%. If I am a home grower I can keep my humidity levels slightly higher then if I am a commercial grower worried about passing microbial testing. As my temps drop like I noted earlier then my kPa range increases. Around day 28 I want my kPa range to be closer to 1.3 so 79 degrees 55% humidity or so. I am not moving out of the 55% range if I am a home grower. If anything when I am closing in on flush or in the last two weeks or so I would be looking to have my humidity around 52% to maintain the 1.3 kPa range. As a commercial grower worried about microbial testing I would be looking to have kPa in the closing weeks up to around 1.4 so if im at 77 degrees I am hoping for around 48% humidity.

All these factors are how I can get my plant to finish when I want it to finish. Therefore breeders giving us date ranges can tell us when to initiate certain phases of the plan. Knowing its a longer flowering time or shorter flowering time can help us determine when to implement certain strategies. This can be pheno dependent too as certain phenos can lean toward parent or grandparent.