Jane Squier’s Super-Efficient Greenhouse Saves Time and Energy

An interview with farmer Jane Squier by Dennis Lucarelli

In her large greenhouse on Salt Spring Island Jane Squier grows subtropical fruit trees for herself and hydroponic ‘living lettuce’, basil and greens for local supermarkets. Her 6,000 sq.ft. (557.4 square meter) greenhouse is heated by an earth-friendly system that includes: a 90%-efficiency wood gasifier furnace, a 4,400 gallon insulated cistern with a wall made of hyperadobe, and an anaerobic digester that converts household and greenhouse waste into methane and fertilizer. Jane’s unique and highly-automated farming system is part of the 2015 Eco Home and Living Tour on Salt Spring taking place on Sunday, July 26. After a casual visit to check out her farm for the Tour, I asked her to explain how it’s set up.

DL: “First, before we talk about how each part of the system works, and how you built it, I’d like to know how you came to be a farmer, and I’d also like to hear about your work in Papua New Guinea.”

Squier: “In the 70’s I did a year and a half stint at a small off-grid farm. I learned about organic gardening, food preservation and ‘appropriate tech’ there and eventually decided to go back to school to study horticulture which is how I ended up getting a fascinating job as a district horticulturist in Papua New Guinea. There we were trying to address the issues of decreasing soil fertility due to changing demographics, and malnutrition.
I set up a demonstration and seed multiplication garden and trained local people to operate it using the unfamiliar techniques of organic gardening. They were used to 25 year fallows and vegetative reproduction. We grew protein-rich crops like peanuts and beans, and set up a tree nursery with everything from passionfruit to avocados to citrus to nitrogen fixing trees. We also set up a co-op for selling vegetables to the coast by back-loading empty airplanes.”

DL: What led to your choice to go into greenhouse growing?

Squier: When we returned from PNG in 1983 my then husband Jamie and I decided to start a hydroponic greenhouse business west of Calgary. Jamie was inspired by an article in Harrowsmith and designed our system essentially from that article. Smart guy!

A combination of great sunlight, low energy costs, high produce prices and technical advice from an innovative agricultural extension officer made our 4000 square foot greenhouse a success and we quadrupled the size two years later. Most produce in the stores was shipped from California so our fresh ‘living lettuce’ was in high demand. There was continuous pressure to expand but after 10 years we decided to sell it as a ‘turn-key’ operation and semi-retire to Salt Spring.

DL: So you went to a smaller-scale greenhouse operation when you moved here here?

Squier: Yes, we brought a 6000 foot structure with us which we sized for the projected demand, assembled it in 1994 and started year round production of butter lettuce which we also shipped to Vancouver Island. In 2001 I bought out Jamie and began operating the greenhouse on my own. I had to make several changes to the system as what was previously a part-time job became much more than full time. I increased the rainwater storage capacity threefold so I wouldn’t have to truck in water, built a walk-in cooler to reduce marketing stress, and diversified by growing basil as well. I was heating with oil (forced air) in the winter and eventually, as oil prices skyrocketed, I reduced production to 9 months of the year. I hated burning oil. After several years I started to feel like the greenhouse was a liability, too expensive to heat, too tall, too big and I was weary of the repetitive work. I decided to embrace the challenge of redesigning the greenhouse scenario and here I am, a happy grower again with a more sustainable and interesting business. I continue to make a decent living growing lettuce and basil in half of the greenhouse, but now the other half is an experimental orchard of 50 semi-dwarf trees including citrus, avocados, guava, jujube, and pomegranate. This past winter I had a steady supply of citrus including grapefruit, mandarins, and oranges. The smell of blossoms this spring has been exquisite and I’m thrilled to see a few tiny avocados forming.

DL: How do you keep your greenhouse warm enough for all that?

Squier: I’m heating with renewable energy now. I qualified for partial funding through the Environmental Farm Plan to install a hydronic system which includes a high efficiency wood-gasifier furnace. Adam Milner and I designed a system that would take advantage of the insulated 4,400 gallon tank in the greenhouse. The tank captures excess heat while the furnace is burning, stores it and circulates it to the different zones on demand. The redundant oil furnace was refitted with a radiator so I have the option of using forced air too. In theory the annual wood consumption should be close to the annual sustainable yield of the trees on my property.

DL: And you’ve added more heat-storage capacity with the adobe walls that retain heated water.

Squier: I did the math and realized we’d have over 20 yards of extra fill inside the greenhouse after digging the holes for the trees and mixing in soil amendment. The subsoil has a high clay content which is great for adobe. I came across the hyperadobe method of building walls on the internet which seemed like a good fit. I sent an email out to friends and ‘the list’ for help. None of us had previous experience other than watching a youtube demo. I purchased a 3000 foot roll of plastic mesh, the type used for onion bags.

We cut the mesh into 25 foot lengths, tied a knot on one end and gathered it on the outside of a bottomless 5-gallon bucket. One person held the bucket/mesh and others dumped 2-gallon pails of fill into the mesh creating a tube of fill which was then tamped with special tools to create a layer. Subsequent layers were laid on top and tamped in place. After the wall was built we ‘mudded’ it to seal the mesh so it won’t degrade. It was great fun. Over 35 folks turned up to learn and help. Now I have a beautiful wall in the greenhouse that serves as thermal mass.

DL: And the about the hydroponic system, how does that work?

Squier: I use Nutrient Film Technique (NFT) which provides a continuous flow of nutrient solution to the plant roots in a recirculating loop. Plants are grown in 100′ lengths of standard eavestrough which are covered with a sheet of extruded plastic punched with holes at optimal spacing. The system has an automated harvest machine which makes fast work of packaging. I don’t think there’s any other way of growing vegetables that is as efficient in its use of water, nutrient inputs and labour.

Plants grow quickly and healthily as the nutrient solution contains all the macro and micro nutrients at optimal parts per million. As soon as the lettuce is harvested the area is replanted which translates into more rotations per year, a continuous supply of produce to the stores and of course more income. No need to weed or spray or sterilize between crops.

For quite a few years I’ve been experimenting with creating organic hydroponic solutions with the compostable waste from my property. It’s my effort to ‘close the nutrient loop’. I started to have success when using filtered digestate, which is the fluid remaining after anaerobic digestion. So I hired Kealan Gell, an engineer with significant experience in waste recovery, to install one of his small digesters and it’s been in operation for three years. The digester converts my kitchen and greenhouse waste into bio-available digestate and biofuel. I pasteurize the filtered digestate for hydroponics and use the nutrient rich solid waste as a soil amendment. The biofuel is used for cooking and enhancing CO2 in the greenhouse.

DL: Do you have issues inside the greenhouse with sanitation and/or keeping the system free of pests or other infestations?

Squier: I use Integrated Pest Management (IPM) to control insects and use no sprays at all. Until I had fruit trees the only significant pests were aphids and caterpillars. The caterpillars are easy to deal with by using screened vents. The odd one gets in and I have a butterfly net to deal with them. Aphids are the real problem and I purchase predator wasps to control them. I also brought in predator mites and lacewings to deal with pests that came in on the citrus. They do an amazing job and I’m starting to have a decent resident population of beneficial insects. Most issues disappear when plants get what they need re heat, humidity and nutrients and I’m working at building the kind of environment that meets their needs.

DL: You mentioned organic inputs and I’ve tasted your absolutely delicious lettuce!

Squier: By definition organic production must take place in a ‘living soil’, and hydroponics doesn’t use soil. So, no, even if the fertilizer inputs are classified ‘organic’ I wouldn’t call hydroponic or aquaponic produce “organic”.

I am committed to growing the highest quality produce sustainably, efficiently and responsibly and though it’s not labeled organic it is healthy and nutritious!

DL: Abundant lettuce, plus your citrus and other tree crops, and a highly-efficient heat and heat-storage system… how do you find the time to harvest all that lettuce, much less plant it to begin with?

Squier: I’m a great believer in practical applications of automation. The greenhouse vents, heating system, harvesting, hydroponics and digester are all at least partially automated. I have purpose built carts for planting out and for harvesting basil. The trough cover that holds the lettuce is attached to a machine which pulls the crop to one end of the greenhouse where I have my ‘packaging station’. I’m not shipping off island anymore which cuts down on time and I only wholesale which I love. I do the greenhouse work on my own and have help one or two afternoons a week with the rest of the property. If I don’t have crop issues (or take on another project) the process is slick.

DL: Thank you, Jane. I look forward to having another look at your greenhouse and innovative heat-storage and automated planting and harvesting system on the Eco Living and Home Tour on July 26th!

Dennis Lucarelli volunteers as VP, Transition Salt Spring and has a small garden at home.

Other Resource Links:

Thom Hartmann: 1.2 Million People Found Jobs in 2014, and more.Renewable Energy, and more  (video link, forwarded by Jean Gelwicks)
Your Winter Vegetables – Brought to You by California’s Very Last Drops of Water? – posted April 6, 2015
TSS-Ideas from Potluck Aug.13,2010(final).doc
Report From Eco-Living Tour Summer 2013 – The Driftwood August 2013