What is a propagation Greenhouse?

  By Andrew Campbell

If you ever look at where your tomatoes or peppers come from when you are in the grocery store, you’ll notice that many can come from Canada all year long. That’s because of the growing greenhouse system in the country, that allows fruits to grow under the warmth of glass, mimicking a summer day. But what you may not realize, is that tomato plant doesn’t always get its start in the greenhouse that it will spend the next several months in. Farms like Jodi & Adrian’s help those fruit greenhouses by supplying the tiny seedlings that will grow into food producing plants. On this tour, the young couple take us on a tour of the farm they’ve built and how they get tiny seeds off to the strong start other farmers will need for their own farms.

To get ready for this tour, I washed my hands and am wearing clean white coveralls to protect the plants. What kind of greenhouse is this and why do we need to take these precautions?

For biosecurity, we don’t want you bringing in any outside germs or bacteria to the greenhouse. This facility is called a propagation greenhouse. We grow plants from seed into small plants also called seedlings. We grow tomato, cucumber, and pepper plants at this greenhouse.

They’re custom grown for our customers who are other greenhouses that grow vegetables. We custom grow their seedlings, deliver them on a specified date, and then they grow the tomatoes, cucumbers or peppers that you buy from a market or grocery store.

This is a fairly new business for you two. Why greenhouses?

We both grew up on farms. A greenhouse is a little bit different than your traditional farm. As you’ll see as we tour, it’s a very large scale operation. Even though it’s large scale, to us, it is still our family farm and we live on site with our young family. We have approximately 100 staff who work here, depending on the season, but we like to consider them as farmers as well. They don’t own the farm, but they’re here working with us every day. They’re integral to our company. This really is what I consider to be a new age of family farming.

Let’s start the tour with planting cucumber seeds and your rockwool block assembly line.

This is our rockwool block assembly line. Rockwool is made from volcanic rock which is super heated and then spun into fine fibers and then cut into blocks. Rockwool is what we grow all of our plants in.

We start by unloading the rockwool off of the pallet and putting it onto a conveyor. Then the blocks are automatically watered. The rockwool blocks have a tendency to float a little bit as they’re getting watered.

The next section lines them all up so they’re straight. Then after that, the blocks are planted with a cucumber seed. A vacuum seeder is picking up the seeds and dropping them on the rockwool. An employee checks the vacuum seeder to make sure there hasn’t been a double seeding or if there is a missing seed. She’s fixing them and then lines them up. The seeds drop through a tube and go right into the rockwool block. Then the seeded rockwool travels along the belt and the seeds get covered with vermiculite that helps hold the moisture in. Vermiculite is a mineral that’s mined and is very consistent. Its purpose is to hold moisture.

Next, each plant gets a stick. When we’re shipping the plant out, they need a stick to clip the plant for support and so that they don’t fall over. A machine inserts the stick and then the plant will grow up beside it. We clip the plant up to the stick as it grows.

A spacing machine picks up the seeded blocks from this line and places them onto the floor where they’ll grow.

In the greenhouse, the cucumber plants are growing now. What goes into looking after a cucumber plant at this seedling stage?

At this stage, the seedling is not too much work. They’re in a block and the spacing machines dropped them off and they’re sitting on the floor. The rockwool block was watered on the line, so it doesn’t need to get watered very often at this age and size.

Our grower/horticultural specialist walks through the rows to make sure that the plants are healthy. He’ll look at germination rates (how many seeds grew into plants) as it’s really important for us to know how many of those seeds germinated. Our customers order a certain amount of plants so if we have a problem with the germination rate, we need to know that right away so that at the end when these plants are ready to be shipped, we know there’s enough for our customers.

After the seedlings get a little bit bigger, they need more space to grow. The spacing machine that put them on the floor goes back and picks the cucumber plants back up and places them in another area of the greenhouse where they have more space to grow.

Cucumbers get fairly large, fairly fast. How long does it take for the seed to germinate and then become a seedling?

This one is about 10 days old. They come fast and we will keep them in the greenhouse for anywhere between 18 to 25 days.

You also grow tomatoes. What do you do to look after a tomato plant?

Tomato plants are an interesting one for us because it’s one of the only ones that we grow from a graft.

Graft? What is that?

The reason we graft the tomato is that several varieties of tomatoes have great flavour or color that the consumer is looking for but a lot of times, those varieties don’t have a strong root system.

Greenhouse growers will grow a tomato crop for about 11 months, so to get that kind of length out of a crop, they need a really strong root system. With grafting we actually grow a separate variety that has a really strong root system.

We then take a razor blade and slice into the stem and then put it together with the desired variety to the stem. The plant is held together with a little clip, and they’ll grow together into a really strong tomato plant with a really good root system and the type of flavor, color and size that the consumer wants in a tomato. We graft each tomato plant by hand.

You also grow peppers. How do you grow them?

We seed them the same way we seed cucumbers. Once the pepper plants are on the floor, we irrigate with a flood floor. The entire concrete floor will flood and it’ll come up to about an inch on the rockwool block and the water will wick up so the plant gets all of its water from below. This way the peppers plants are never wet on top.

Peppers need a lot of sunlight. We also use grow lights.  They give off about 85 micromoles of light which means that on a dark rainy day like today, we’re adding additional light to replace that sunlight that we’re not getting.

Hopefully the sun will come out today.  If that happens, the computer system will recognize that the sun’s out at a certain intensity and it shuts the lights off. We hope for sunny days because we don’t like paying the power bill on these lights!

Heating the greenhouse must also be a big expense. Heat plus lighting the greenhouse must mean big bills for energy.

Energy is definitely a huge cost for us. It’s one of our biggest costs. That’s why it’s important to manage it and to have the computer system that’s turning it off accordingly and making sure that we’re not wasting anything.

I’ve noticed a little insect around. Are insects good or bad in a greenhouse?

Well, it can be either. There’s some that are good, some that are bad, and some that are neither. We can have issues with different bugs flying into the greenhouses especially in the summertime when things are really active outside.

For example, thrips are a bug that we get from outside that can be a problem. On the plants there’s a little bag with a hole in it filled with bran, a bran mite as well as a swirski mite. The bran mites eat the bran and the swirski mites eat the bran mites. As the bran mites start to all get eaten up in the bag, the swirski mites are slowly released out of that bag over a six week period. The swirski mites then eat the eggs of a thrip. This is called integrated pest management. Bugs eating bugs. We really try and do 100% with bio-control like this.

If this didn’t work we would need to use a pesticide system. But because of the life cycle of the bug which lays eggs that hatch a few days later, then you would spray one day and then again when the eggs hatched.  Bugs eating bugs is usually a lot more effective and ultimately, I think the consumers like to know that the farmers are trying to use the least amount of pesticides that they can.

One more thing you grow is lettuce. Tell me about growing lettuce. How do you do it?

We grow lettuce to fill floor space in the off season. We’re very busy through the winter and we have slower periods through the spring, summer and in the fall as well. We started growing lettuce to fill that empty floor space. It’s a greenhouse vegetable and we like that it’s a very clean product. We don’t like to bring in outside products that will also bring in pests and disease that might affect the propagation of the seedlings that we grow for our customers.

Lettuce is marketed as a living lettuce so it grows, and then we cut it off just at the root and we sell it. We grow a few different varieties including Boston lettuce, red oak lettuce, green oak lettuce, and some romaine. We’ve run trials of other products like bok choy. This is a new product that we’ve been doing the last couple of years. We’re working on finding out what the consumer likes the most and what can be packaged nicely and sold that way.

Adrian, Jodi, thanks so much for the tour today.

Watch Andrew Campbell’s full Dinner Starts Here video interview