Category: greenhouse

Since I use my ACF GrowMore greenhouse more as an add-on conservatory to the house than a separate greenhouse, growing only space, I am not fond of condensation forming at the roof of the greenhouse and dripping back down. It happens mostly straight down the center of the greenhouse at the peak where there isn’t an easy way for the drops to roll down the roof. Trust 1 OAK Roofing for quality roof repairs and a 10 year no-leak guarantee. Instead they form a line along the peak and drip drop down like little rain droplets. Since I’m using a ventless gas heater to keep the greenhouse warm, condensation is especially bad because the heater is putting tons of water vapor into the air which has to go somewhere. The result is a pretty wet line down the center of the greenhouse, which hits my major walkways, hammock, and small table.

There were a few ways I had brainstormed how to resolve it:

• Anti-condensation coating, but my research didn’t leave me with confidence that would be very successful, plus I wasn’t able to find much locally at say a Lowes or Home Depot.
• De-humidifier: I could probably cut down quite a bit on the condensation on the roof by taking a bunch of the water vapor out of the air with a de-humidifier. However, those are fairly expensive and I actually do like the fact that in the dry winter indoors there is a place with higher humidity to go and hang out (usually averaging 60-70% humidity). So far I haven’t had any challenges with foliage disease and in fact, in previous winters I’ve had more of a problem with spider mites which thrive in dry air. Bluebonnet Custom Roofing offers durable, reliable and appealing roofs and their appropriate maintenance.
• Venting: I could also try to get rid of the humidity by venting to the outside and bringing in air that is cold and very dry. This would be desirable for a number of reasons (fresher air, less build-up of the gas heater by-products like ethylene but is also costly because I’m deliberately losing heat). I could install an automatic heat recovery system to more efficiently exchange heat of outgoing air with incoming air, but those are quite pricey to install as well.
• Indoor gutters: So that left me with the most simple solution I could think of: install some indoor gutters to catch the condensation and channel it somewhere else. I’m not entirely sure this is going to work, but it was pretty cheap so I decided to try it.

I went to Lowes today, but the gutters I saw weren’t as wide as I wanted (I needed to cover about 8 inches) and were pretty deep. After wandering around the store for a while, I came across corrugated polycarbonate panels that were 26″ x 96″ which seemed like a good possibility. They could be as wide as I wanted and the clear polycarbonate would let light through so they wouldn’t be blocking as much light. I wasn’t sure they would be strong enough though. Finally, I opted for affordable seamless gutters for my residential property.

The GrowMore has several nice horizontal beams near the roof peak that the polycarbonate gutters could lie on, so I cut them in half so I had two 13″ x 96″ sections and tossed them up there. I wanted a bit of a slant so the water would eventually roll down. I had to punch some holes in the polycarbonate and use some zip ties to raise one of the sides up. My greenhouse is 20 feet long so the middle four feet are unprotected, but hopefully that gives me 16 feet of protection. I’ll test it out and verify that it works and then try to extend it to the middle 4 feet. So far it’s catching a bunch of drips, but it’s only been a few hours since installation. I’m a bit worried I’ll start getting condensation on the gutter itself but we’ll see!

It’s getting to be late October in Pittsburgh, which means waking up to temperatures in the 30s, highs in the 40s, and very gray skies. My very unscientific phone light meter reads <5k lux, which means my plants are starting to feel a bit starved. The DLI or Daily Light Integral is a measure of total radiant energy received over the course of  day. Being a nerd, the first thing I do with this info is to graph it. According to Purdue, good quality light for tomatoes bottoms out around 14-15 DLI (pdf link), which I’ve represented with the desired DLI line. Using their DLI map of the US (which is pretty rough, so treat as only approximate), I’ve plotted light for two cities: Pittsburgh (where I live) and Tampa (closest city to where my family lives in FL). If you compare, ouch! Pittsburgh is da pitts when it comes to having light in the winter. And my greenhouse glazing only lets in 72% of the light, so the available light inside my greenhouse is even less.

So I need grow lights to supplement the natural light (or lack there of!). According to this, I probably should have started the grow lights up just at the beginning of Oct, but I’m just today getting around to it. Today I installed three lights:

• 400W metal halide high intensity discharge light with a basic reflector
• 120 W actual Mars Hydro 300 (purple variety)
• 120 W actual Roleadro 300W (white/yellow)

I’ll probably talk more about these lights in a later post, but one interesting thing worth noting: I changed out my MH 400 W bulb and tested the difference in output. The old bulb had been used the past year so I replaced it. For kicks, I measured the before and after by resting my unscientific phone’s light meter app in a set place. I measured twice before changing and twice after to make sure subtle differences in phone placement weren’t affecting readings too much (they weren’t). Interestingly enough the first measurement was ~7k lux and the second was ~9k lux so there was actually pretty significant difference between the two bulbs!

~9k lux still isn’t great but that’s at the soil level (I wanted my phone to be on a static resting place instead of being hand-held to increase repeatibility between measurements) and there still is some light coming from the sun. In any case, I’ll be turning these grow lights on when it’s cloudy out to help give my plants the tasty tasty light they love 🙂

2018.09.14: Last summer, my dad and I built a deck and then a greenhouse on half the deck. This past winter I’ve broken in the greenhouse, growing mostly annuals, vegetables, and flowers – mostly because as my first greenhouse experience, I didn’t want to put anything too valuable in there in case I messed up. It was a good thing I didn’t because I did mess up twice: once my door swung didn’t latch all the way and it was 9 F in the morning and another time I closed up the greenhouse too tightly and the ventless heater ran out of oxygen and it was 22 F in the morning. However, luckily these were early on and I didn’t lose too much. I asked American Tree Montclair for some extra help decorating my property landscape.

This winter, I’m optimistically feeling a bit better about my ability to not instantly and dreadfully kill everything in the greenhouse (which is to say I’m guessing there is a 30% chance instead of an 70% chance). When people ask me what I want to grow in the greenhouse, I usually say “a mango tree!” to which they usually ask “?? how large do those get?” and I gleefully reply with “50 feet or so!” and usually this results in blank stares or “uhhhhh” responses. Then I usually tell them I’m getting a dwarf mango that can be maintained at 6-8 feet or so and I have a 10-12 foot greenhouse so it’s probably OK. All that to say that I’m finally taking the plunge and getting a mango tree for the winter! Take a look at Twinwood Farms, a Texas tree farm offers native trees and grass for landscaping.

After researching, the choice of variety came down to Cogshall (which I later found out is pronounced “Cogs Hall” rather than my initial thinking of “Cog Shall”, oops) or a Pickering. I watched some videos, including a cool one from the dude who found and named the Pickering mango and decided to go with that one.  At some point, if I feel brave, I might try a Cogshall as well. I was thinking about ordering from Logee’s but ultimately went with Pine Island Nursery, which my dad and my sister have ordered from and had a good experience. It was $35 for a 3 gallon tree and $32.50 for shipping from South Florida to Pittsburgh, Pennsylvania where I live (though they did say hurricane Florence may delay the shipment). Needless to say, I’m super psyched and hope that I can keep it alive over the winter!

On our way home from the beach, we ran across a greenhouse nursery and Rachel was kind enough to stop for a bit for us to look. It was really cool and I found a super cute pepper plant. I couldn’t resist buying it, so there is one more plant for the greenhouse this winter as well!