High tunnel construction - Part 1

The high tunnel project officially got underway on the 22nd with (friend) Duncan not only lending me his truck but also his time. We started at Windsor Plywood and picked up about $600 of materials, including 1.25" Sched 40 PVC, .75" Sched 40 galvanized water pipe, and a stack of lumber.

We began by setting up a single guideline close and parallel to the seasonal creek. If, at that point, I knew how wide the tunnel was going to be, we could have run another parallel line at that distance. In this case, I wanted to use up some existing 24' wide polyethylene. But the 24' is what gets pulled over the structure, not the interior width. Furthermore, some of the poly width is consumed because it has to be wrapped around 1"X2" battens along each sides' edges Accounting for that fact, I figured on only being able to use 23'. Mathematically, one could then approximate the width using the equation Circumference = PI X Diameter and assuming that the high tunnel is essentially a half circle; an upside down half-pipe for all you boarders out there. So, doubling the 23' to account for the full circle that the equation is based on and re-arranging it to solve for Diameter (width)we have:

Diameter = Circumference / PI = 46'/3.14 = 14.6' or 14' 7"

In practise, I mumbled something about PIthagoras, both of us briefly tried and failed to find a pencil and we began cutting the water pipe into 4' sections. I then post-pounded in all the posts on the marked side, leaving 2' in the ground and 2' above. Then we slipped one end of a 23' coupled piece of PVC over one of the posts and bent it over in an arc to see what length it naturally gravitated to. Turns out, right around 14'.

The .75" water pipe, BTW, went into the sopping wet soil really easily, so easily that I was concerned that they might also come out really easily. But when I tried to pull them out, I nearly pulled my back out first. Which probably means that I'll need some sort of pipe jack to extricate them if/when we leave the property, particularly if the soil is dry at the time. In any case, I'm confident that they will not come out due to structural lift on a windy day.

With the width now known, we ran another guideline square and parallel to the first line (oddly, I didn't mention Pythagoras even though I used his 3,4,5 rule for finding square) and pounded in the other sides' posts before slipping each 23' PVC rib on to each of its designated posts.

The area we marked out is as flat as unlandscaped ground gets around here, which means there's a bit of variation in elevation from post to post. In addition, the posts I pounded in were 14' apart plus or minus maybe 3", plus their degree of plumbness varied by a few degrees. All this to say that, once all the PVC "ribs" were mounted on posts, we had to adjust some of them up a little so that, when viewed from the top of the structure, the tops were even.

One of the critical components in the building of this type of high tunnel is the top purlin which goes on top of the highest point of the ribs, running perpendicular to said ribs, from end to end. In this case, the top purlin is also 1.25" PVC which we carriage-bolted to each of the ribs. Having the top purlin on top of the ribs prevents the polyethylene cover from sagging between ribs at the top where water is at most risk of ponding. Once a volume of water has accumulated at the top, the weight stretches the poly and allows even more water to accumulate which then threatens to collapse the entire structure.



To finish off work day number one of this project, we ran a guideline on the inside of the ribs at about 5' above ground and used it to screw 1"X2" wood purlins on either side. While the purlins were 12' long, they did not meet up nicely at the mid-point of the 3rd rib spaced at 4'. There was simply too much variation in the installation of the ribs for that to happen. As a result, we had to overlap the purlins, above or below each other to ensure all ribs were effectively tied to one another. This ended up looking quite bush-league and, as you will see in a later post, was re-done quite skookumly.

Flock's flux

We've had a small flock of chickens since moving to Salt Spring. We started with two hybrid laying hens that we got as wonderful parting gifts when we left Haliburtion in 2009. We had raised those two - plus 26 of their 'sisters' - from day old chicks to 6 weeks old in our suburban Saanich basement. I would not recommend doing this unless you are aware of the many issues like smell, noise and canabalistic violence that can ensue. But it was an unforgettable experience in any case.

A few weeks after we moved to Salt Spring, Hannah and Laura got 5 bantam heritage birds from a Vancouver Island breeder. The whole lot of them spent their nights protected from raccoons and mink in a coop that the kids and I built out of scrap lumber and Windsor Plywood giveaways. They stayed safe from raptors in a 30X30 bird netting-covered pen. About a year ago, Pauline put a call out on the community list for a particular breed of rooster, for the purposes of mating the hens. Almost immediately someone nearby offered her rooster for a Valentine's weekend of debauchery. Shortly after, one of the bantam hens got out of the pen and was killed by a hawk. Happily, 'Ginger' had left a clutch of 5 fertilized eggs prior to her death which her broody ex-coopmate warmed up over the next 3 weeks to produce 4 viable chicks. Of these four new home-growns, 2 were roosters. The roosters met their end somewhat unnaturally in July.

About the same time Ginger's chicks hatched, we bought an unsexed Ameraucana chick which turned out to be female. We were also given 3 more silver sebrights, 2 of which were roosters. Last summer we sold a 'mating' pair of sebrights, leaving one mating pair for ourselves. Then, just prior to Christmas, we moved the whole flock from our backyard setup to a new home on the farm. Given all the extra space, both inside the coop and outside in the pen, we started adding to the flock by purchasing 3 barred rock pullets.

Since then we've been having a very distressing problem. Despite taking others' advise to hang several strings of fishing line above the coop to keep out avian predators, it was only a couple weeks before we lost one of our prize heritage hens to a hawk. Because of this, I built 2 70'long X 6' wide covered tunnels, thinking that this extra covered area would give them ample space to avoid or escape attack. But just after Christmas, another of our favorite hens and surrogate mother to Ginger's eggs, was killed by a hawk. Most recently, our beautiful white bantam leghorn was killed although the hawk could not or did not fly away with its kill, implying that perhaps it has run out of birds in our flock small enough to remove.

To conserve the last of our bantam birds (a rooster and 2 hens), we moved them back home. Just before we had moved them to the farm, a dump of wet snow ripped and flattened the bird netting, rendering it unusable. So the girls replaced it with lots of ORANGE baling twine, copiously criss-crossed to and from each pen post . Orange apparently confuses hawks and other birds of prey but I'm not sure of anything these days. In any case, we missed the sound of Splash's (the bantam sebright rooster) crow so it's nice to have him back.

Oh yes, just before New Year's we picked up another 3 full-sized pullets from a guy on the island who's liquidating all his farm animals in preparation for a move. Two out of the 3 went to the farm but the runt of the litter is at home with us, where the other small birds are unlikely to abuse her.

A couple of days ago I got out the mega roll of baling twine and did the same overhead criss-cross at the farm pen that the girls did at home. It took about an hour and a half and was actually kind of fun because I tried (successfully) to do it without cutting the twine (I figure that if this protection technique is also unsuccessful, at least I can salvage my twine, sort of). With this new grid - which BTW, reminded me of a complex map of aviation airways-, the natural tree cover at one end and the larger average bird size, we're hoping that predation will stop. If, after a month or so, we've not suffered any further losses, we'll resume our flock expansion. The coop can probably handle 40 birds and we only have 9 at the moment. Demand for our eggs is significantly higher than our ability to supply them.

And, with that, I shall conclude this post with evidence of our third serious bout of winter this season, which occured a week ago and lasted two days. Oh, and a little known fact: last Wednesday (or possibly Tuesday), it snowed in all Canadian provinces.

Pomodoro ad nauseum

As promised, the tomato "trellis" post which, it turns out, has become much more than just trellises. Sadly, the photo I posted is the best I could come up with. Our other photos show the trellis but also conatin very unflattering images of the resident farmers.

We had a pretty dismal tomato crop last summer for a number of reasons. First, we didn't get them transplanted until summer (i.e.June 22). That's too late. The plants we got from Hali were in big 6” pots but still, they've got to begin spreading their roots unrestrained earlier than that. The year earlier, I transplanted Haliburton Ray's tomatoes on the 17th of March. But the next day there was a killing frost and he had to start over, which he did – successfully – and goes to show two things: that starting seedlings too early has more risks than rewards; and that you can often bounce back from things that look catastrophic. Nevertheless, transplanting mid-May last year would have been fine. But June 22nd? No. Again, that was out of our control.

The crop plan I’ve been drafting for this year calls for us to seed tomato plant starts in the first week of March for transplanting late April. But on second thought, given that we’ve got a plant start business to off-load unneeded seedlings for our own farm, perhaps we’ll do a couple of successions a few weeks apart. If all goes well on the first round, we’ll have early tomatoes. If not, the later batch can bail us out.

The second mistake I made last year was arbitrarily putting them in the shady second bed. I put them there simply because I started planting stuff from the long side and put the fingerlings in first because they were starting to rot. Next priority was the tomato starts. Why I didn't just mark off the beds and find a sunnier bed a little further east, I'm not sure. Putting them under the maple shaded half the bed in mid-afternoon most of the summer. Another consequence of this decision was that our salad greens ended up being in the sunniest spot, a place they certainly didn't need to be.

Third, they were not under cover which is not recommended here due to the cool, rainy weather we inevitably get either in the spring when they are very small or in the fall when they are very large. This sort of weather promotes blight. Last year, though, we got rain unexpectedly at the end of June, shortly after we had transplanted them. Fortunately, they did not get blight. In fact, friends of ours who had theirs in a greenhouse did get blight. They figure it was because it was too humid inside. They had been watering them a fair bit, apparently, so when it got cloudy and rainy, the humidity and lack of air circulation allowed the blight to get established. I note this because we will be housing our tomatoes in a greenhouse this year. Anyway, we did not escape late blight which occurred sometime during the September rains. It hardly mattered though because most of the fruit would not have ripened anyway. We partially salvaged the crop economically by canning green tomato salsa and selling it at $8/pint.

Finally, I don't recall off hand what if anything we used to fertilize the starts but apparently it should be light on nitrogen and heavier on phosphorus. This year we're going to get a sack of rock phosphate to give them what they need. I’ll also water them more frequently although probably not much volume. The reading I’ve done recently suggests that periods of dry followed by lots of water promotes blossom end rot and cracking. I don’t think we had either last year -just the blight- but still, better safe than sorry. On the other hand, they will be growing in a partial swamp this year so maybe they won’t need much irrigation at all. I'll also space them at 18" rather than 24'. I think that by the end of the season, they should just be starting to touch one another. At two feet spacing, we generally had 6" between them at the end.

One of the last things I did on Foxglove Farm last May before finding our land was plant tomatoes. Interestingly, they put their tomatoes in 12” wide hills into which I used a bulb auger on an electric drill to produce deep holes into which the tomato seedlings were deeply buried, exposing only 6-8” of stem and leaves above ground. But that only worked because the root ball of the seedlings was 1”X2”. Last year, our tomato plants had a 6” diameter root ball so I had to use a shovel to dig holes. And we didn't put them in hills because I decided I had a hate on for raised beds of any sort - didn't believe in them – but I'm not sure about this year. I may very well put them in hills and drill out holes since our seedlings will be much smaller and planted out much sooner. In fact, if the early April forecast looks good, I could see planting them out then, and using a low remay tunnel within the high tunnel for extra protection against cold.

The bright spot of the last year's failed crop was the T-post and wire trellis I built. For this scale of growing, it was quick, effective and reasonably cheap.

We started by transplanting the tomato starts by digging deep holes every two feet (a little closer next year, 18"?), adding some organic fertilizer, putting one end of a 10' length of baling twine at the bottom of the hole and burying much of each start's root ball and stem, leaving only ~8" of plant above ground. The other end of the baling twine just sat on the bed until I built the trellis.

For the trellis, I pounded in 10' T-posts every 12' along the row but the ones at the ends I pounded in at a ~20 degree angle to vertical so that they leaned out past the row ends. Then I used 10' 2X4's to temporarily prop the end posts straight up while I ran 14 gauge wire end to end and put on as much tension as possible with turnbuckles. After I kicked out the 2X4's propping up the end posts, there was even more tension on the wire as the post wanted to go back to its angled orientation. I used some light gauge steel wire to tie the main 14 gauge wire to the same height on each intermediate post. The “free” ends of each plant’s twine were tied to the high tension wire above. Every 7-10days, when I pruned the plants, I also wrapped the plant's new growth around the twine.

In the high tunnels this year we won't have to bother with the T-posts since we'll have the structure of the high tunnel to tie baling twine to. But our plant starts will be smaller, probably in 2" cells as opposed to the large 6" pots that we got from Hali. My concern last year was that the end of the string below the root ball would come loose, but that didn't happen. I suspect the weight of the soil and the action of the water and soil cement the string into place. When I cleaned up the tomatoes last fall, the strings only came out after a very sharp tug.

In which I babble for an hour...

One of the cool things about Salt Spring Island is its radio station, CFSI. I've actually been on the station before, in fact, about a year ago when I co-interviewed my friend and finance/energy-blogger just prior to her presentation here on the various forms of doom we are likely to experience some day. But yesterday I was the guest as my friends and show co-hosts Dennis and Belinda peppered me with questions about all things Chorus Frog Farm. AFAIK, in order to post an audio file on blogger, you have to actually make a simple "movie" with (in this case, about 15) photos which, I hope, capture us, the farm and the west coast.

Resolutions

It's sunny but cold these days; think Winnipeg in September. I was planning to harvest some greens for New Year's eve munching but that was not to be. The greens should be fine by the middle of next week when temperature are forecast to rise a little.

This blog has been particularly quiet recently because we went on a little vacation to California (where we hoped to escape West Coast Rain) and subsequently to Arizona (where we were successful). We saw lots of mega agriculture in both places but California's Salinas Valley was particularly interesting in terms of its scale. Miles of plastic-covered raised beds which, among other things in the summer, produce 6 million heads of iceberg lettuce per day. It's a terrible waste of water, fuel and soil, of course, to grow such a water-dependent low-nutrition crop only to have it shipped to Boon Dock, Newfoundland yet my Industrial Engineer mind was fascinated just the same.

While on vacation, we had a lot of time to talk about all things farm. We brought a seed catalog along and, on a few of the longer drives, made lists of what we will be growing for plant starts and for growing in our fields. The situation we have now is so much different compared to last year. We're starting at the beginning of the season as opposed to the middle. We'll have high tunnels (rodwilling), chickens, lots of infrastructure already built (more time to concentrate on growing) and just a whole year of mistakes and successes in our recent experience to learn from.

Which brings me to a list of New Year's resolutions:

Not that we had any choice in the matter last year, given our late start, but we will have a much greater selection of produce this year. People must have been disappointed last year at our limited selection. We compensated with baking and preserves to the extent we could - and I will still bake bread this year - but we hope to shift the focus to unprocessed food this year.

We will only grow greens under cover to avoid soil splash, fallen conifer needles that float in rinse water and are hard to remove, and, for brassicas, airborne pests like the cabbage moth. The washing machine as a greens spinner, in theory, works well but ours has a leak which causes an electrical ground fault so I have to fix that by spring.

Polyethylene-covered low tunnels worked poorly for us in the fall/winter, as far as I can tell. Even using twice as many sandbags as prescribed, the plastic still blew off during wind storms (80+km/h). I will have much more on this in a future post.

We will grow potatoes using only top quality seed which we will plant much earlier so as to avoid the disease we encountered on the Yukon Golds last year. We will grow more fingerlings as they were a hit plus we will experiment with a couple other varieties for which we can obtain organic seed.

Tomatoes will go in our high tunnels and, compared to them being outside partially under a large maple tree, we'll have more heat retained over night, less chance of blight and more light. We didn't sell any tomatoes last year, a crop that can really pay the bills if done right. I had meant to talk more about our tomato growing over the summer but was overtaken by events. This will be my next post.

We'll continue to grow Hakurei turnips to radish size except I'll probably seed them even closer than before using multiple passes of the precision seeder as per Haliburton Ray's suggestion. He harvests several bed-feet at a time, bunching the ones that are the right size and composting the ones that are too small or otherwise unsellable. Last year we painstakingly selected individual turnips and waited for others to catch up. Seed bought in bulk is too cheap to worry about economizing it. After harvesting, say, 6 feet of a bed, we can immediately reseed with something else, instead of waiting until all of the crop in a bed is removed.

We will probably not grow many green onions or, if we do, it will not be via transplant but rather direct seed and, again, in a dense planting. We will, however, grow lots of bulb onions which fetch attractive prices and, apparently, were in relatively short supply last summer. We also had no trouble growing or selling our bulb fennel so we'll do much more of that.

We'll be on a bit of learning curve for our summer plant starts for sale (tomato, pepper etc) in terms of varieties and quantities but Pauline's made a lot of notes on how to improve the winter plant starts based on our experience. First, people wanted many more broccoli, cauliflower and Brussels sprouts starts than we had for sale. We will also grow out more large brassicas ourselves for produce sale. We have to do a better job protecting our brassicas from cabbage moth this year and, to accomplish that, we will ONLY plant brassicas of the same growing characteristics together. Last year we had all kinds of plants in our brassica beds, for example, green onions, turnips and radishes. We had a cover over the brassicas but it became too much of a pain to uncover and recover every time we wanted to harvest a few radishes. This year we'll do a whole bed of large brassicas, cover them and leave them for several weeks before fertilizing, spraying (maybe) and weeding. Also, we need to give these large plants more room.

We didn't have any flowers or herbs last year but this year we're starting early enough to do so. We may not do so many herbs as to make a big crop out of them but we will start enough to sell and to eat. We really want to make the farm a little prettier and more attractive to pollinators by planting lots of flowers. How exactly we accomplish that in the context of operational efficiency remains a mystery to me. I suppose we'll just interplant them amongst crops that have similar lifespans (e.g. tomatoes, rather than radishes or peas). And, of course, they can't be under a low tunnel.

I haven't quite figured out what our wash station should look like yet but I have some ideas to make things more ergonomic. Last year we placed a sheet of corrugated tin roofing on the ground upon which we garden-hosed things like turnips and radishes prior to bunching. There wasn't much room under the apple tree to build a dedicated wash stand last year but this year our wash area will be moved adjacent the chicken coop. I will probably extend one side of the coop roof several feet to cover a large wash area under a couple of conifers about 8' from the coop. In that area, I would build a counter height slanted metal wash stand and run a water supply to it. I would then copy Pauline's observation from her volunteer day at the UBC Farm of an overhead sprayer that stays on while both of the worker's hands are freed up to handle the produce.

We also need a bar fridge to set up at the farm stand. In it we will put eggs, greens and other heat-hating foods.

All in all, a satisfactory 2010. Not much money but much learning occurred. I think I'll be disappointed if we don't triple our sales in 2011.

Happy New Year!