The Smart Greenhouse Upgrade (And the Cabbage Moth War)

We are in the middle of a major heat wave here in Kalamazoo – it’s been in the 90s the past week and there’s no end in sight. Upside, it has been really rainy over the last few days, so it’s a good soaking for the garden!

Upgraded Pest Control Strategy!

Cabbage moths got into the brassica bed, so I sprayed with Btk. Bacillus thuringiensis kurstaki (Btk) is a naturally occurring bacteria that lives in soil. It’s a subspecies of Bacillus thuringiensi and it controls moths and their resulting larvae, in this instance the cabbage caterpillars that have been eating up my brassicas. It works by making crystalline proteins that paralyze their digestive system and then they die.

I chose this route because it’s thoroughly nontoxic to other creatures. Birds can eat those caterpillars and be just fine. It doesn’t bother any other bugs but the moths/subsequent larvae. The product I linked above is a liquid, and I mixed up a half gallon in my new pump sprayer and went to town on both sides of the leaves of my cabbages and broccoli.

In the other front yard bed, I’ve been beset by slugs and/or earwigs. This required a dual approach of diamataceous earth and slug bait. Diamataceous earth (DE) is basically an organic silica that is made from the fossilized remains of tiny, aquatic organisms called diatoms. It works by abrading the exoskeletons of crawling bugs like earwigs and slugs, and causes them to dry out and die.

The drawback is that it only works when it’s dry and it’s been wet and humid. Once it dries out, I’ll have to go back out and reapply it.

The slug bait uses iron phosphate to kill slugs and snails. I discovered that slugs come out of the dirt in my raised bed at night and that’s why I didn’t see them during the day. I put down the bait in the middle of the bed, and then spread a border of DE around the perimeter of it. Again, it needs to be kept dry, so I’ll get out there and reset the beds once it dries up some.

My brassicas, beets, and beans will rise again, but it was certainly disheartening to go out there and see them chewed on, particularly since I’ve kept the raised beds fairly consistently covered with this netting, which I’ve held up off the plants using election sign frames. It’s the “fairly consistently’ part that let me down, though. Nobody to blame but myself!

Upgraded Greenhouse Tech!

I have noticed that the vent windows in my Costco greenhouse have been open pretty much constantly during the heatwave. As longtime readers know, not only am I kind of lazy, I am also a giant nerd when it comes to data. I know that the windows open when it’s 70 degrees in the greenhouse. I also know I lost seedlings in the greenhouse to damping off this spring. My current temperature management is essentially a big outdoor thermometer, and I have no idea at all about the levels of humidity at any given time.

Not any more.

Since I ran power to the greenhouse, I’ve been thinking about how best to gather data. Enter a hygrometer! This cool little gadget measures four things: temperature, humidity, dew point, and vapor pressure deficit (VPD). I understand the first two, I’m still working on getting my head around the second two. Here’s a NOAA article about the difference between relative humidity and the dew point. Here’s a wiki on VPD that still makes my brain hurt. I am hoping to learn more and figure out how best to use these four data points!

What is really cool is that it hooks up to my wifi and refreshes every hour. It can refresh more often, but I don’t want to run the batteries down. Right now it hangs on a peg in my greenhouse outside of direct sun, and it gives me readings on the Govee app. I already used this app for my exterior lights, so it was nice to not have another app to wrangle. Here’s a couple of shots of the app reporting. One is from just now and one is from last week that blew my mind.

I picked up some Govee 15 amp power plugs while I was at it. Now I have the potential to really automate my climate control since these are programmable in the app and connected via wifi. Two of these are in the greenhouse, one on the east wall box and one on the west.

For example, if the humidity is over 70%, I can turn on both fans in the greenhouse to run at a crosscurrent to circulate the air. That will help significantly with damping off as I start seeds for fall crops in a month or so. I see this working for me in the winter as well, for example, if the temperature goes below 35 degrees, kick on the heater to blow warm air across the greenhouse workbenches. Then, when it’s 45 or so, turn it off. I’m excited about the potential. Here are the plugs, and I get a kick out of how the outlet looks utterly dismayed!

Water catchment update!

Putting gutters on both sides of the greenhouse has been a brilliant move I should have done sooner. That said, it will be an off-season project to install taps a little lower on the easternmost and westernmost barrels in the array. Right now, when it’s been raining for several days, it’s easy to draw water from the current taps. When it’s not, though, I can clearly see how I should have placed them lower. I bought the hardware to do so today, including the correct step bit for the job, and will stash it in the greenhouse until I take them down in October.

Tomato Madness!

So, this was May 25:

And this was Friday, a little over a month later:

I took a short trip to New Orleans and the BSE and Gadgetron video called me to tell me that the deer had themselves a little potato and tomato buffet. They sprang into action, netting everything for me, and the plants have come roaring back. I’m excited to see Midnight Snack cherry tomatoes about to burst forth, I could eat these all day long, and likely will in a couple weeks.

How are things in YOUR gardens?