Indoor winter growroom

[matt_citrus]

Brought the trees in about two weeks ago, just before the fall storms. Almost every tree is flushing now.


The lights are creating a 10°F temperature delta.


A few of the trees require almost daily watering. They may overtake the space within a couple months.

[CanadianCitrus]

That’s awesome!! How do you control humidity and airflow?

[Millet]

Nice set-up.  I notice all of your trees are growing in Root-Maker air root pruning containers.

[Tortuga]

How do you like those Air pots? Do you think they are worth the extra dough? I assume watering must be kept on a tight schedule to avoid drying out

[brian]

Really nice looking trees.

The air pots do dry faster than solid pots, but they really do work as advertised and it is impressive to see the root system of a tree that has been in one.  I use air root pots for all my trees until I have decided they are large enough, then I put them in solid containers and begin pruning them.

Is your floor concrete or something ufinished that can get wet?  I imagine you have excess water draining into the floor, and you might have to spray for scale.

[Millet]

All of my container trees are in Root Maker air pruning containers.  I agree with Brian that the pots do create a fabulous root system.

[matt_citrus]

Humidity and airflow - There's an HVAC vent into the room, and a door. The heater is running for the house more frequently now with the lower temperatures, so that's the positive pressure into the room. Between the vent and keeping the door almost all the way closed, the humidity has been in a good range. There are 30 citrus trees transpiring water vapor into the air! (and evaporation from the pots.) I also have a floor fan on a timer to turn on for 30 min every 2-3 hours for more circulation. It's a very relaxing - if bright - space to be in. Lots of blooming now, too.

Agree with all the comments here about the Root Maker pots, especially for up-potting. It's easy to cut the zipties and expand/add panels around the existing root ball. Combined with the 5-1-1 mix (I generally add more perlite to be closer to 5-1-2) it's a forgiving setup. You can get a feel for the watering by the weight of the pots,, and there's a clear relationship between canopy size, growth, and diameter of the pot for how frequently watering is required. Some of the smallest pots get water every day and they're growing like crazy (finger limes in particular). Tricky to think about up-potting again during constant flushes.

Brian, good question and something I stressed over in the months leading up to the transition. I ended up building a wood platform on casters, covered with panda film to catch any water (any sturdy plastic barrier will do). The trees sit on top of this. I also used some existing plastic catch basins on wheels as well for some trees. So, all the water is caught above the floor and I can maneuver around to get into the thick of the trees to sweep/vacuum as needed. Downside is losing 6-8" of allowed height but well worth avoiding water damage. Need to get the greenhouse planned .

Thankfully, have not had to deal with any scale in the region. Lots of caterpillars and earwigs before they came in, and of course the big cicada emergence. The surprise pest was a single Boxwood Psyllid on the pomelo but that was months ago.

[Olivier]

Thanks for sharing your setting Matt, I love reading about it since there is little information on such greenhouse online. Unless one wants to grow weed...

I'm currently working on a similar setup myself. Still a work in progress but it gives an idea.

My biggest concern are the coldest times during winter. Last year my grow space was very cold and the trees got dormant. The top of the house would be warm because of the lights but the roots would remain cold preventing any growth.

I insulated with reflective insulation sheets, similar to bubble wrap. I hope this will be enough to retain enough of the light heat and keep the roots warm enough to keep the trees thriving.

[matt_citrus]

I'm "only" running ~17 true W/sq ft. Two sets of Kingbrite 650W LED light bar fixtures (10x LED light bars of LM301H + deep red/infrared). The mix tests at 3400K and 175 lumen/W (and ~1660 total PPF). The LED drivers are not 100% efficient; each fixture pulls closer to 750W from the wall to generate 650W LED output. Kingbrite was highly recommended by some of the other research forums.

The original Kingbrite mount was 100mm spacing between light bars. This would have created a more pronounced PPFD spike in the center. I remounted at ~300mm spacing to distribute the light over a substantially larger area and make the PPFD coverage more uniform.

Lumens or foot candles aren't a great measure of PPFD because it's spectrum dependent. But it's easier to measure the former. 1700 FC at the plant bases and 2700 FC a little over a foot below the lights. If it's close to sunlight spectrum, that's 350-540 PPFD.

Running 12hrs on/12 hrs off. Tops of plants are getting DLI in excess of 25, the bottoms are closer to 15. I planned for 21 for healthy growth.

VPD is averaging 0.9-1.0 with range of 0.6-1.2. Trying to keep humidity up to sustain beneficial mite populations.