Category Archives: Winter Growing

Radical new hoop house design to save you time and money (Edited)

Since being transplanted to Ohio and taking a short hiatus from full time farming, I’ve been wanting to do some backyard growing. I knew that I wanted a small hoop house, but the design was escaping me. So many of the different small houses I had built were too flimsy, or didn’t have a door, or just too much work. So I thought and thought, for around 3 months before I came up with this design. It has only been up for 2 weeks, so it’s not thoroughly tested, but so far, it seems to work.  Let me know what you think!!


After I shared this video, Eliot Coleman emailed me that he had used this design back on a house in 2002 to overwinter field crops. Good designs always reappear.

Eliot Coleman slanted endwall 2002

A similar house that eliot designed back in 2002

Do you have ideas to make this a better design?  Comment below!!

What we learned from our Overwintering Spinach Trial

For some reason I’m fascinated with spinach. Perhaps it’s the different colors, textures, and growth habits, but all of it intrigues me. We sell a lot of spinach on our farm: baby, leaf, and bunched.
Last year we decided to do several trials. One was in the fall comparing 8 different types, looking at growth habits, hardiness, and disease resistance. The other was a ¼ acre, 9 variety, overwintering trial, looking at the same characteristics. We are located in zone 4a, and can get quite cold during the winter.
The process started Mid-summer with identifying the area for the trial. We wanted well drained soils as spinach doesn’t like wet feet, especially during the winter. We choose a sloping, Hoosic gravelly loam that had previously been in spring greens. The field was tilled and fertilized, beds where made, and the Spinach seed was planted mid October, 3 rows on the bed, 18” apart. Seed spacing in the row was 12-16 seeds per ft.
After seeding, the spinach germinated and was cultivated once before winter covers were put on in late November for overwintering. We used one layer of Typar 518 or 2 layers of Covertan 30 weight. The winter of 2014-15 was severe, with good snow pack. The rowcover was needed, because when part of it blew off, that area died. (Thankfully it didn’t destroy all of any one variety, so we still were able to collect data from all varieties.)
Spring came on slowly, with late April snowfalls. We didn’t’ get out into the fields until April 12th when we fertilized the spinach with krehers 8-3-3, putting down 60# N to the acre. We were, however, able to check the spinach in late March as the snow receded.
One problem we had was that rowcovers on spinach can cause rubbing, or white spots on the leaves. We didn’t want to hoop the spinach, so we ended up delaying harvest by pulling row covers completely off. This was done approximately at the end of April.
early trial
We started harvesting spinach from this section the last week of April, and continued through the last week of May when the last varieties bolted.

The results: the field was evaluated on May 15th when all the pictures were taken. I evaluated bolting again at the end of May to confirm our earlier results and make any last minute observations.

A note about the pictures: We clear-cut the field early May for a wholesale order, that is why many of the leaves look a little ragged.

Screen Shot 2015-09-15 at 6.33.56 AM 2

Space- Solid all around spinach. A little slow growing and had a tendency for the bottom leaves to be yellow.

Emperor- Wow, what a great spinach. Early, tall, dark green. It did have a tendency to have deformed leaves and show some bottom yellowing. Bolted quickly as well, but for an early spinach this was great. We really like this variety for bunching. Scored low mainly because a low percentage of plants deform.

Giant Winter- Bolted early, one of the quickest to size, but color wasn’t great. Leaves yellowed as well.

Giant Winter
Pidgeon- Best spinach overall. Sized quickly, took forever to bolt, held off disease and deformity was okay. Great color, easy to harvest.

Tyee – An old standard. Minimum score on all aspects was a 6. You can see why people still grow this.

Racoon- Absolutely beautiful spinach (was our favorite in the fall trials) Very upright, easy to pick, bolted relatively soon though and flavor wasn’t great. Very good disease resistance.

Bloomsdale- Older variety, grew a bit slower and bolted relatively soon, but scored best for flavor. Very savoyed leaf.

Regiment- Another nice variety. Not on our list to grow again since their are much better varieties.

Renegade- Second best score overall. Large leaves, slow bolting, relatively nice flavor, good disease and deformity resistance.


They say the proof is in what you grow next time, so here’s what we’re going to overwinter again. Space, Emperor, Pidgeon, and Renegade. Even though Emperor scored lower, it’s earliness and size were winners for us. Its all about what you want in a spinach, and as our overwintered spinach only has to last several weeks before the regular field plantings come in, we will take earliness and yield over bolt tolerance.

We also overwintered baby red Russian kale in the field. Of course it bolted quickly, but would have been fine for one cutting of early spring greens.

red russian kale

To check out more pictures of the trial, click here!  

What are you looking for in overwintered spinach? What varieties have you tried?


How to Build a Poor Boy Germination Chamber

Someone asked me the other day how we germinate seeds here at Kilpatrick Family Farm. I figured a quick blog post would be in order to show our cheap, and easy method.

The outside of our germination chamber

The outside of our germination chamber

We have heated benches in our smaller transplant house. I’ll do another Post on these latter, but the short version is that a 30 K BTU standard water heater is used to heat water which is pumped through small tubes on our benches. This system keeps the root zone warm, which is the most important part for strong growth.

What is needed for good germination?

Seeds need 3 things to germinate. Moisture, Heat, and in some cases light. We wet the trays before they go into the germination chamber. While in there, we either cover them with rowcover or germination domes to keep the moist. Heat is supplied by the heat tubes running underneath. The probe that powers the heat system is sunk in a small pot in the germ chamber. For those crops that need light, we’ll either place them on the top in the chamber or bring them out after a couple days. That is enough time to give them a jumpstart.

The guts of the heat system.

The guts of the heat system.

Here is a closeup of the tubing running under the bench and germ chamber.

Header for the heat tubes

Header for the heat tubes

What our cheap germ chamber does is concentrate that heat to a temperature which most seeds germ quickly at (80F). This is done through a few sheets of 1″ and 2″ foam board held together with great stuff and a few long roofing nails.

Heat box closeup- note the nails in the corner pinning it together.

Heat box closeup- note the nails in the corner pinning it together.

Here’s a shot of seedings just coming out of the germ chamber. We’ll stack trays several high in there for a capacity of over 100 trays.


Tomatoes just out of the germ chamber

right now the chamber is chock full of ginger germinating!

Ginger starting in the germination box

Ginger starting in the germination box

During the summer, when it is too hot, we germ in the cooler or a cool basement room.

NRCS webinar

I was privileged to be selected to give a webinar for the NRCS last week about high tunnel production. Webinars are hard to give, as you can’t see your audience or hear yourself, so feedback and feeling that you are connecting with your audience is tough.

We briefly covered high tunnel placement and construction, crop planning, and different crop production.

NRCS recorded the webinar. You can access that HERE.


Overall, it was a fun experience.

Tips to prevent Spinach Diseases in Tunnels


The more we grow spinach in the greenhouses the more disease we get. A classic case for better rotation. But, with limited tunnel space and our customers unending need for spinach, we have to keep growing it. Cladosporium Cladosporium on spinach

Unidentified Spinach DiseaseUnidentified spinach disease, any ideas?

There are several ways that we have found to keep diseases to a minimum in the greenhouse. Many of these are just common sense but there are a few innovative tips out there as well.

  1. Keep humidity in the tunnel to a minimum. This may be the most important thing. Moisture in the soil or air helps with the spread of disease. If the inside of your plastic has water beading up on it, it is too wet. We keep our end vents open above 40 degrees as well as 2 small vents that stay open permanently.
  2. Avoid overhead watering or water early on a sunny day so plenty of time to dry out. Some growers have switched to drip, which they are finding works great.
  3. When disease does appear spray immediately to prevent spread. We usually hit it first with Oxidate, which helps kill spores. Then we will spray either Actinovate, which is a preventative group of good bacteria, or copper which protects the leaves and kills spores.
  4. Another way people are preventing disease is hot water treating seed. Many of the diseases come in on the seed, such as Fusarium or Cladosporium. Some extension services own hot water seed baths which they loan out to growers.

While researching diseases in our tunnels earlier this week, I came across this great resource about identifying spinach diseases.



Moncton, NB Winter Growing Conference

I was super lucky to be asked to present at a 2 day winter growing conference in Moncton, New Brunswick earlier this week. Just where is Moncton?

One thing that was notable about the trip was the amount of snow they get. Even though they are in a similar growing zone (4b), they had between 4-5 ft of snow on the ground when I got there.

They asked me to do 3 talks, the first one on Greenhouse structures, prep, and soils. One interesting thing I learned is while we orient our houses for maximum sun exposure (east-west), they also have to worry about heading the houses into prevailing wind so that the wind blows the snow off the houses.

ACORN Tunnels

The second talk I gave was on succesion planting and profitability. Although we have run numbers on what crops make us per acre(return per year((RPY)), we don’t have numbers on return per week(RPW) of growing season. This is much more important when you are dealing with tunnels and every day needs to be making you money. Adam Montri of MSU did a talk on this this winter and I’m including the slides here as a resource.

ACORN succession planting

Economics of High Tunnel Production Adam Montri

The last talk I did, which was preceded by a delicious, locally sourced dinner, was on how we do season extension on the farm. This talk was open to those in the community and I tried to share how many of the principles could be done on a smaller, even garden scale.


Throughout the day between sessions, there was great conversation had by all. I picked up some tips and tricks that other growers are using and can’t wait to impliment them this year on the farm.

Webb City Conference

Earlier this week I was privileged to co-present  with Adam Montri of MSU at a special winter growing conference put on by the Webb City Farmer’s Market and Missouri Extension. They were hoping they would get 75 people but by the time the conference was happening they had 162 attendees!!!  People traveled from as far away as 250 miles and 4 states to come to this. Most attendees didn’t have tunnels or were just getting started as farmers. I presented 3 different talks and also did a Q&A session.

First talk was on winter greens production.

Lettuce in January_

Second was on Season extension on the farm- from equipment, to soil, to different crops and more

Season Extension

The 3rd talk I did was on Marketing the farm….  it was the first time I’ve done a marketing talk this long and it actually went well…

Marketing the farm

There was a lot of interest on our bubble washer that we use to clean greens on the farm- here are a few pictures that I took of it this week. The first one is of greens going in before it is turned on.


Heres a short video of it working….  excuse the unprofessional quality of it….

bubble washer video

Here’s another picture of it bubbling away….

People are always asking where to get the Blower motor- here’s what we have found to be similar to what we used (they don’t make exactly what we used now)

Blower Motor


Mid-Atlantic Fruit & Vegetable Growers Conference

Had the privilege presenting last week at the MAFVG conference in Hershey, PA. I talked twice, once on Winter crop production and once on tunnels and tunnel innovation.

MAFVG 2013 Winter Production

MAFVG 2013 Tunnel Innovation

The MAFVG is a great conference, huge trade show, but a little disappointing as it was primarily geared toward industrial conventional growers. However, did run into a few other farmers I knew from around the country which was nice.

How snow affects us here at KFF

After a few dustings in November and early in December, winter hit with a vengeance last week. The snow started late Wednesday evening and continued into Thursday, ending by mid- afternoon. At the farm we spent most of Wednesday getting ready for the snow and frigid temperatures expected this week.

First order of business was to clean up areas on the farm that would need plowed or driven. It’s funny how when the banks melt in the spring and you go, “Oh, thats where that went” or “Whoops, should have cleaned that up in the fall.” In an effort to maintain the chaos when the world gets coverd in white, we place stakes along any important areas that we don’t want to hit with the plow.

We also needed to get some hoop houses recovered. The week before, we had a vicious wind which came through from the Southeast. (Our normal wind hits from the North, and our houses are stabilized against that direction.) The wind was so rough, it ripped out ground anchors. Jonathan and I ended up cutting ropes and letting the plastic fall. Later, Sam and I took 2 hours and put the plastic back up. One hoop house was much harder to fix than the other because it uses 2 sheets of plastic – therefore, a much more complicated assembly.

The onion tunnels also needed protecting. We over-winter onions for May and June sales of big, green-topped onions. They start in the greenhouse in trays in August, are transplanted in October, and then covered before the ground freezes. We usually cover them with plastic, but this year we felt we could get away with heavy rowcovers.. Sam and I applied it, pulled it taunt, and added plenty of sandbags to hold it down.

Here’s a picture of putting up the hoops a month or so ago…

Here’s the ends of the tunnels – the rowcover wasn’t long enough so we used two covers.

Finished Product…and covered with snow below.

We also covered the row of Surfer and Megaton leeks we left out in the field to overwinter – just a simple, double layer of P-30 cover to break the wind.

The last thing we did to get ready for the storm was to put our flameweeder into the haygrove. We had this crazy idea that instead of taking the plastic off like we are supposed to, we could throw the 4.25 million BTU heater inside the tunnel and melt the snow off. We’ll keep you up to date with how it’s working…

And we’re still eating good out of the greenhouses- here’s a salad I made last night with stored chinese cabbage, mesclun from the high-tunnels, and ham from our piggies.

How we insulate our greenhouses

One thing we do here at KFF is as the nights get colder is add some insulation on the north side of our houses. Our houses are oriented East/West, not by design but more because of the lay of the land. As the sun comes from the south, we try to keep that side open as much as possible to the sun but insulate the north side where no solar gain is going on. 


Here’s Dylan and I laying ou the insulation- it’s pretty light so we can lay it right on top of the spinach and it’s okay. We use bubble foil (best price here It comes in big 125 ft rolls, shipping will kill you so we have planned getting it when we are near Farmer Boy’s stores. 

As it is only staying up for 3 months max (December- February) we only attach it to the top with a simple loop of duct tape. Make sure to get it nice an tight to the soil on the bottom as you are going to want to attach it down there as well….

We attach the bottom with ground cloth staples right into the soil.  Here’s what it looks like after it is installed.

Note the air space between the insulation and the top of the rollup to allow for ventilation. having the insualtion there also allows us to store the covers during the day right up against the edge. They are in the center of the house now but harvest is easier if they are against the edge and you aren’t walking or kneeling on them.

Here’s a picture of the finished haygrove. We only put the insulation up two feet in here as it was more to block the cold air from seeping in from below the edge of the plastic. The haygrove doesn’t have a baseboard as it’s meant to be a 3 season house and thus cold air gets in relatively easily. If you look closely at the greens in the first bed you can see the edge effect causing the outside rows of greens to grow more slowly.

Another thing we do as we build permanent houses is add 1 inch blue-board around the perimeter from soil level to a foot down. This breaks the cold and frost creeping in and seems to really help the edges to stay warmer.