1 of 1 people found this helpful
veggie, There are many gardening website you plug in your location or zip code and it provides you their estimate of last frost. But lets talk a little bit about how the tower garden allows you to start earlier than that. Do you have a dolly? If so would you be able to move it into the garage if temps drop below 40. Do you have an aquarium heater? Do you have a TG cover?
I'm in NC and our last frost is often mid April however I start my TG's in late March and will move them in my garage if needed. I also have an aquarium heater which will maintain the water to 65 degrees which heats the plants also.
I have mine on a dolly however it is on the deck. While I have a overhang that can protect it from the elements it certainly isnt enough for inclement weather. I like the idea of an aquarium heater.
HI veggie, You may find the following excerpt from one of my many earlier posts on this topic helpful:
...if using a submersible heater in the nutrient solution and applying proper "hardening-off" practices, your outdoor TG start date will be earlier than "safe date" specified in guides that are geared toward convention soil based growing.
The "magic" explained: Heat rises. If you keep the TG nutrient solution tub temperature in the optimal 65 to 75 degrees F range (favoring the lower end of that range when possible), it warms the plant root zone and the TG internals. Being located at the bottom of the TG, the warmth of tub rises to warm the air immediately adjacent to the plants. Ergo, it may be 32 F outside but it's warmer around your plants.
Adding a cover system or blanket (at night) that extends down to the ground will also help retain the tub warmth.
...more about the tub heater:
A TG nutrient solution tub heater should be fully submersible, shatterproof (no glass), rated in the 200 to 300 watt range and an accurate temperature control that includes the TG's optimal nutrient solution temperature range of 65 to 75 degrees. Here is a link to the heater I currently recommend:
Aqueon Pro Heater
In all cases, you should maintain the TG nutrient solution temperature in the 65 to 75 degrees F. range (favoring the lower end of that range when possible). Your growing season is over once you can no longer stay within that temperature range.