Hey everyone, I’m new to this subreddit and greenhouses in general. I’m hoping y’all can help me figure out a few things so I don’t inadvertently kill my lemon tree. I live in zone 7a and recently built a 6 ft x 12 ft greenhouse (plastic and aluminum kit) and put down about 2.5 in of mulch for the floor. I also put in some old pavers and made a few little benches to keep everything off the ground. The greenhouse gets full sun throughout the day seems to be retaining heat well. I’m concerned that the mulch isn’t enough and my lemon tree will die. Thoughts?
by boilitfirst
9 Comments
If you don’t provide active heating then yes, it will die.
Not sure where these rumors that putting a plant in a greenhouse is somehow going to allow people to grow stuff without spending money – but this rumor is ridiculous and needs to stop.
” Lemons are subtropical fruits, meaning they will do best in warm climates and hardiness zones **nine through eleven**—this means lemon trees are not cold-hardy, so you’ll have to have mild to warm weather at least to grow these plants successfully. “
Your mulch isn’t enough for what? If you are thinking heat retention then yes it won’t be enough or do anything really. You need a heat source or at minimum a buffer medium like water in tanks that can heat during the day. Also with such an empty space your greenhouse will cool off quicker.
Chances are it’s already too cold in there during the night. Once the sun drops greenhouses don’t generally do a good job holding heat without a supplemental heating source. Can you move the lemon tree inside your living area? You’d spend significantly more than the value of the lemon tree trying to heat a greenhouse like that over the winter.
I second what the other comments have said.
I have a 6×8 greenhouse, and it pretty much drops to ambient temperature the moment the sun goes away, unless I supply heat to it.
I’ve heard of the water drums and techniques like that, but I come from a place where sun is very seldom during the winter, so supplemental heating was my only option.
I am in 7b have a 6 by 6 greenhouse and a lemon tree. You should take it inside to a sunny room and get a grow light. If you want to use the greenhouse then bubble wrap it and get a grow light and an electric heater. The heating can get pricey.
8×12 here in zone 8a, with two Meyer lemons and a key lime.
For sure yours are going to die unless you put a heater in there. Depending on what your overnight lows are, you might even need some insulation. I use an electric oil filled radiator heater and have no trouble keeping them alive.
The [r-value](https://www.energystar.gov/saveathome/seal_insulate/identify_problems_you_want_fix/diy_checks_inspections/insulation_r_values#:~:text=R%2DValue%20is%20a%20measure,and%20locations%20in%20the%20home) of most greenhouse panes is like around 1-2 at best. For comparison, the recommended r-value of insulation for a structure in zone 6 and above is 50.
You’re gonna need a heater.
I added some extra insulation to my panes by fitting [bubble wrap](https://youtu.be/qNnI5H_35Qw?si=R0W9vSYYItkJmT2E) over them. It doesn’t look all that nice, but it helps spend less to heat over the winter.
Not much help but I’m in 5a and just bring my lemon tree in during the winter and keep it next to my sliding back door. It actually does better in the house in winter than it does outside during the summer so I’ll probably just keep it inside from now on, it smells pretty nice too.
Use incandescent Christmas lights and string them around the tree. That and cover it with a row covering blanket should be enough. Check out the millennial gardener on u-tube.