Winter is coming – Keep your plants growing in the cold

  Dec 16 2019

As the warmer months draw in, many growers encounter a familiar issue – heat.  This time it’s the opposite end of the scale that many battle during the winter – its too cold!.  The good news is that it’s usually easier to add heat than remove it.  For example, if you are growing in a loft it can be a nightmare to keep heat levels down during the warm period and but keeping them up during the cold could be as simple as making a few small changes or simply adding a heater on a timer or a thermostat.  In most cases you’ll want your daytime (lights on) temperatures around 24 -28c and your night-time (lights off) 2-5c less. Consistently low temperatures can have your plants thinking the season is coming to an end and may try to ripen their flowers/ fruit early, leaving you with a sub standard crop. Large temperature swings will stress them and often stunt growth and prevent the plant fulfilling its potential.  Let’s look at some basics that might just bring your temps back to where they need to be. 

Run your lights at night – Grow lights create heat so It makes sense to run them during the night when the ambient temperatures drop significantly meaning less need to run extra heating.  

Control your extraction – Without any kind of fan controller, your extractor will be running at full speed and pulling too much of that much needed heat out.  If you are running an intake fan, think about if you can draw the air from a warmer source – eg if your are growing in the loft, can you pull the air from a spare room in the house?

Add a heater – There are many options to add heat to your grow room.  A popular choice is a tube heater, these come in different sizes and wattages to suit the size of grow room in question.  Some people will use a min-max thermometer or air comfort device to log when temps are dropping and simply connect the heater to a timer to come on when required.  Better still, connect one to a thermostat and let it take care of it for you.  If you are struggling for space in the grow room itself, a good option is to place an oil filled radiator next to an intake vent and let the the warm air be drawn in that way.

Nutrients – Plants don’t like their food too cold, ideally your nutrient solution should be kept between 18 & 21c.  If you let it drop much below this, the plants could suffer shock and fail to uptake the nutrients from the mix, causing growth to slow or even worse, stop altogether.  If you have a reservoir that will hold a few days worth of feed then it it would be wise to add an aquarium thermometer to make sure you are staying within these parameters.  Adding a tank heater if required will keep the solution at the correct temperature.  Make sure you choose the correct heater for your tank size.  Over heating the nutrients could bring about root diseases such as pythium.  

Raise it up – Hot air rises so the root zone of your plants are more often than not in the coldest part of the room.  Simply raising the pot off the floor to allow air to flow underneath will help keep them happy.  This can be done simply with anything you have to hand such as and old pot cut down or better still something like an RTA try that will also catch any spillages or water run off.  

All of our staff are seasoned growers and would be more than happy to talk you through solutions to these common issues, Why not pop in to one of our stores or give us a call?

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