Greenhouse Day

If you’ve ever visited Farmstead Creamery, you probably noticed the long, white plastic-film greenhouse lightly humming away next door. Some folks don’t, asking, “what greenhouse?” even though it’s bigger than the creamery. But if you’ve driven down Moose Lake Road on a winter’s evening, you’ve probably seen the golden glow of the grow lights and wondered what on earth those crazy ladies at the farm were up to.

Growing vegetables and tilapia fish, that’s what! The symbiotic relationship, in tandem with beneficial bacteria that processes the fish waste into nutrients the plants use to grow, is called aquaponics. The roots of the plants filter the water so that it returns fresh and clean to the fish, and so the cycle begins again.

Our beloved kale salad and mixed greens all come from the aquaponics, which needs tending multiple times a day. But some days the system needs more of an overhaul, which is what occupied this last Monday (rather than barn muckin’ chicken pluckin’ or hay balin’). This Monday was a greenhouse day.

First, there was the usual fish feeding and plant watering. Mom harvested that day’s round of fodder (sprouted grains for supplemental animal feed) while I poked lettuce seeds into growing medium. In a week or two, the cheery seedlings will be ready to plant in the system, waving their eager green and red-flecked leaves towards the sun.

In our aquaponics systems, there are three main types of growing systems: two large rafts with floating rigid-foam panels that have holes drilled in them for the plant roots to reach through to the water below; NFT (nutrient film technology) trays like long rain gutters with lids that also have holes for the plants that access a thin ribbon of moving water at the bottom of the tray; and media beds filled with baked clay marbles that offer structural support for plant roots. Each system works best for different types of plants. The rafts are great for lettuces but also kale, Swiss chard, and bok choy. The NFT works best for smaller plants like cut-and-come lettuce, endive, young basil, and brazing greens. The media beds serve the needs of root crops like carrots, beets, and radishes, as well as offer a stronger footing for longer-term crops like tomatoes, peppers, eggplants, and cucumbers.

Last fall, we expanded the media bed system by adding Dutch buckets (individual square, black pails for growing long-term crops) along the west wall. A year later, eggplant bushes tower higher than me and tomato vines stretch across the ground. It was a little tricky to work out the kinks, with the occasional bucket overflow and finessing the draining system. Surely, there must be enough PVC pipe in the greenhouse to serve at least five homes!

This fall, we are expanding the media bed system again but with flood-and-drain beds. Instead of a continuous inflow of trickling water with a continuous outflow through a drain pipe back to the sump tank, a flood-and-drain system is watered heavily but periodically and then allowed to drain. It also allows us to place beds farther away from the water source (sump tank) and in places inaccessible for water return.

In short, any bare floor space that has more room than is needed for walking, washing, or care of plants is up for grabs for additional growing space. That means yet another phone call to our rep Zack at Farmtek to order supplies.

“Can we use this 100-gallon reservoir as a flood-and-drain grow bed?” Mom asks. We walk through the concept that involves a slotted PVC pipe at the base to collect excess water and draw it out through a bulkhead fitting to the drain.

“That should work,” Zach consents. “If the plastic walls bow out too far, you could make a reinforcement structure from wood or metal, but it’s already built to hold the pressure from the water. Let me know if this works!”

It used to be a huge grumbling scene with the delivery semi-trucks, but now that we’ve expanded the parking lot at Farmstead, turning around is much easier for them. Still, when that ship ticket comes in, they probably draw straws for whose turn it is to roll down that gravel lane to drop off the next odd item we’ve purchased. This time, three large white water reservoir tanks, 30 bags of the clay media (which likely weight 40 to 50 pounds each), and a few odds-and-ends fittings was the stack with our name on it.

“You got that greenhouse full yet? What are you going to do with all those plants?”

“Eat them,” we grinned. I already had baby cauliflower plants ready to go in, along with kohlrabis. We lugged in the white tubs, over two feet wide and nearly seven feet long, and hauled in the bags of media. The day was cloudy and cool, perfect for a long work-day in the greenhouse with heavy lifting. Keeps you warm!

It took a little troubleshooting to get the white tank-turned-media-bed up on enough rigid foam to drain into a shorter blue bed for growing cut-and-come greens (hopefully including spinach!) before heading to the drain. This system allows two rounds of plants to pull nutrients from the water before it’s returned to the earth.

After finishing all the PVC hookups, we piled in the clay media pebbles. Seven bags each in the big white tanks, a bag and a half each in the smaller blue tubs. I also had seven Dutch buckets to refurbish, pulling out old pepper or tomato plants, washing up the tubs, sifting out the roots and debris, then refilling the tubs with a mix of old and fresh media, and planting new cherry tomato plants. In the washing process, I’d pour off the rich, brown water from collected fish nutrient and pour that over the new media beds as an inoculant to give them a jump start.

Between the hauling, the washing, the sorting, the filling, the fitting, and at long last the planting, I smelled of clay dust, was soaked from the knees and elbows down, and had a few fresh scrapes on my knuckles. But five new beds were ready to start growing great foods all winter—baby greens, zucchinis, cauliflowers, beets, radishes, and more. It’s one step closer to personal and community food security during the long winter months by increasing the farm’s ability to grow its own.

In just a few weeks, the brown clay pebbles will be lush with little green leaves—a testament to hard work on a greenhouse Monday. I’ll bet that first bite will taste sublime! See you down on the farm sometime.