The tomato grafts look great this year, the best yet. My plants were running a little behind schedule, and I was a little worried because the healing period has taken a couple of weeks or more in years past. If I could just get them healed up and growing in a shorter period of time I could still make a May 1st planting date. The traditional formula for a quick recovery is warmth, high humidity, and most commercial growers put the plants in the dark for a few days. I had resisted the dark part, it seems weird, but this year I decided to embrace the whole concept. Now, how to fulfill these requirements quickly and very cheaply? Introducing the “Hepicot 550 Healing Chamber”:
What holds temperature well? A cooler! What’s the cheapest form of moist heat that comes with it’s own thermostat? An aquarium heater stuck into jar/flask! How do we tell how warm it is? A really cheap indoor/outdoor thermometer! The tomato plant is just for scale-he’s been healed up and out on the light bench for a week or two.
Here’s close up of the “heat bomb”. The aquarium heater (about $10) needs to be in water or it will overheat and die. I use an erlenmyer flask due to it’s narrow neck (slows evaporation) and wide base (no spill), but a mason jar would work just as well. Check the water level every day and top off when necessary. The thermostat on the heater only has up or down, you have to play with it to find the temperature you want.
I used the cheapo indoor/outdoor digital thermometer. You’re looking at a typical ambient temperature down in the lab. Once dialed in, the incubator held a steady temperature between 80-85 degrees F.. The humidity is naturally high at those temperatures, and the open neck on the heat bomb adds even more. I only misted around the plants this year, not on the plants.
So the freshly grafted plants go into the chamber and the lid is closed for about 4-5 days. The plants LOVED this new chamber- they didn’t even wilt despite having been chopped and clipped. After 4-5 days in the dark, the plants are already healing up, and it’s time to transition back into the light. To keep the heat and humidity in during this phase, I used bubble wrap taped over the cooler opening. Amazingly, this proved nearly as effective as the cooler lid itself. After a day or two, I start to vent the cooler, dropping temperatures and humidity back to ambient.
And here are the results. I did two rounds of grafting and only had one fatality. The plants were healed and unclipped in 7 days flat. Like I said, they never even wilted in the chamber, and were already growing again by the time they were pulled out.
Of course, this is completely scalable. Is this the prototype for next year?