How Low Can You Go?

February is such a tempting time of the year.  It's still cold, but spring feels like it’s just around the corner, and we are anxious to get things rolling.  One of the big things that we want to do to increase how much food we grow in our backyard is to lengthen the growing season.  If you simply rely on Mother Nature, the frost-free date in central Iowa isn’t until May 10^th.  We aren’t willing to wait that long, so we’re taking matters into our own hands.

Last year we built a cold frame and we plan to use it again this year.  This season we’ve decided to also try a low tunnel.  A low tunnel is essentially the same thing as a cold frame, just a different shape, and the end goal is the same.  It’s a small structure that uses the greenhouse effect to warm the soil and protect plants from the cooler outdoor temperatures.

Lots of places sell low tunnel kits, but we thought it looked simple enough to just build one ourselves.  We even found this great example.  We picked up a few supplies, and built this handy low tunnel in just a couple of hours.

To anchor the low tunnel, we used 6-inch long pieces of ¾-inch diameter PVC fastened to our raised beds.  We drilled a couple of holes through one sidewall of each piece so that we could fit the head of a screw through it.  Then we simply screwed these anchors to both sides of our raised beds spaced about 2 feet apart.

The basic structure of the low tunnel is arched pieces of ½-inch diameter CPVC (chlorinated polyvinyl chloride) pipe.  We looked at regular ½-inch PVC first, but the CPVC was more ductile and only a little more expensive.  It would be easier to bend the CPVC into a hoop shape without cracking it, so we decided it was worth a little extra cost.  The CPVC was sold in ten-foot long sections, but that made the low tunnel a little too tall.  After cutting each piece down to nine feet, the height looked much better.

The ends of the CPVC hoops slide right into the PVC anchors.  Next we added a “spine” of ¾-inch PVC across the tops of the hoops to help make the low tunnel a little more rigid.  The spine is fastened to the hoops with just a couple of plastic cable ties.

The last step was to drape a sheet of 6 mil plastic sheeting over the PVC “skeleton.”  The sheet of plastic should be large enough to reach all the way to the ground on all four sides of the low tunnel.  We’re holding the sheet of plastic to the ground with some landscaping blocks and railroad ties that we had lying around the yard.  This traps the heat inside the low tunnel and stops the wind from blowing our plastic sheeting away.

One really nice thing about this design is that we can always add anchors to our other raised beds so that we can move the low tunnel to any garden box we choose.  This low tunnel should be an easy way to start our veggies earlier in the spring, and keep growing things later in the fall.  It’s a simple and inexpensive way to stretch the Iowa growing season and produce even more fresh food!

We're Off And Growing!

That's right, our urban farm is really starting to show signs of growth. And in more ways than one. Let's just say that it was a very busy and active weekend; so much so that it's taken til Tuesday night to find time to write about it! To start with, we headed back to our garden area and found these beautiful green shoots coming up out of the ground.

Those are from the garlic we planted last fall. We planted two varieties, and so far every single clove of Georgian Crystal has some leaves poking up through the mulch. Strangely, not one of the Chesnook Reds has appeared yet, but different types of a plant can have different times to germinate. No need to panic yet, and if nothing else, we're looking at 25 heads of garlic minimum, if we can get them through the growing season. They don't need any maintenance so far, but it won't be too long before they generate long stalks (scapes) that we'll have to trim back. For now, we just wait.

Next we headed over to the cold frame we built, for our cold season crops. It's been a weirdly warm spring so far, so it was over 65 degrees outside when we lifted up a glass pane to check the temperature within.

It might be a little hard to see on the photo, but that's our thermometer reading nearly 100 degrees! It was actually 110 when we first looked, but we lost a little bit of temperature while taking the picture. And honestly, that's fine. 110 degrees is way warmer than we needed for our first few veggies of the year, so we took one of the panes off to vent a little bit. Since it's going to be in the mid-to-high 70s all this week, we'll keep that panel off so we don't cook our seeds. If it were a more typical spring, we'd probably need the glass to capture some heat during the day so things don't freeze overnight.

Even though it's unseasonably warm, we're still starting with cold-hardy crops. It's March in the Midwest; for all we know it could still snow again! For that reason, we stuck with the early season basics in our cold frame.

Spinach, from Burpee, an old packet from the year we first started gardening. Some radishes we nabbed at a bigbox store a few years back. And that guy in the middle is a newcomer. Mache, also known as corn salad, is a supremely hardy salad green that you can supposedly grow well into the winter. Neither of us has ever eaten it before but it really sounded like a good option to try. And we found seeds from Botanical Interests, a neat family owned seed company that prominently refuses to use genetically modified plants. We're eager to see how they turn out.

We planted these seeds into a third of the cold frame box and gave them a good drink of water. The idea is to wait a week or two before planting the next third, and so on for the final portion. If all goes as planned, the harvest times should then be staggered as well, and we'll have a longer window in which to eat all our produce.

So there you have it. We're now up to five types of vegetables that have either sprouted or at least been planted. Garlic, broccoli, spinach, radishes and mache. That sounds like the start to a pretty tasty meal, and it was a good accomplishment for the weekend to get it all going. But believe it or not, that wasn't our main task of the past few days. There was also quite a bit of construction going on. Stay tuned later this week for an update on some pretty significant groundbreaking. Being an urban farmer sure keeps you busy, but it should all be worth it as our plants (and plans) continue to grow!