Signs of Spring

The expansion continues... 16 new SIPs are built (for a total of 24), and all but 7 are now loaded with Baccto Pro potting mix. Later today I'll pick up the rest of the potting mix and fill the remaining SIPs. I'll add the fertilizer just before I plant each container.

I finally planted the greens that Bruce started for me. 6 kale, 3 chard, and 4 Asian greens. The chard took a beating last night (they were not under a cold frame). There was ice on the tops of my cold frames this morning - apparently from the wind chill.
The salad mix seeds I started under a cold frame on the 6th have been doing very well. I'll eat the baby greens and thin the container back to a few plants that will be allowed to fully mature.
The roots are showing up... Radishes on the right, barely visible beets on the left. The carrots have not popped through, and are off the image to the left.
I also started some tomatoes under a cold frame:
and some beans:


The cold frame is keep the soil temp 10-12 degrees warmer than the soil without protection. I'm excited to see how these tomatoes and beans do compared to the transplants I'll be getting from Bruce next month.

In this set of rectangular boxes I've seeded Sweet Annie, Korean Licorice Mint, and Bachelor Buttons. I'll add jasmine scented Aztec Nicotiana in a couple weeks (the instructions were clear not to seed it before the danger of last frost). All will grow 2-6' tall, and are useful as medicinals, edibles, or teas, etc.

On the 5th, 26 All Blue seed potatoes were potted in these containers:

Nothing showing yet...

Though Spring is certainly showing in the lilacs. We can't wait for these to bloom.

Restarting Compost

I took advantage of the unseasonably hot and sunny day in Chicago yesterday to get my compost bin back on track. Because I'm composting on a roof, I chose a homemade compost bin design made from a 45 gallon trash can. I drilled holes in the sides to allow oxygen in and excess water to drain, then cut a flap in the bottom to extract the finished compost.

Home compost is usually generated using one of two basic methods of digestion: anaerobic (without oxygen) or aerobic (with oxygen). Both need moisture and will produce heat. There are three main drawbacks to anaerobic composting - it doesn't generate enough heat to kill pathogens and seeds, it smells, and it takes a lot longer than aerobic composting.

Aerobic digestion requires moisture balance & regular turnover to feed it with oxygen. I had not been doing either for a very long time, so my compost bin had become a soggy smelly mess of slowly breaking down food & garden scraps.

To kick start the bin I had to get rid of the moisture quickly. I didn't have space in the can for enough dry material to get to the ideal moisture level (something like a wrung-out sponge). Instead, I laid out a tarp on my neighbor's roof and spread out the compost in the sun.

Within a few hours enough moisture had evaporated, and I shoveled it back in my bin. In all this took me about 30 minutes (not counting the several hours it sat in the sun).

Since I had not been achieving the high aerobic temperatures (131-155 degrees F), I chose not to use the compost in my planters yet. However, if I turn the compost every 3-4 days and use the lid to keep the rain from over-watering it, I'll have plenty of weed- and pathogen-free compost ready for a summer feeding.

Extending the Season with Cold Frames

(Welcome, Brad, SIP-growing Chicago friend and guest-poster. We hope to see your updates often.)

Last summer I started growing with SIPs after reading Bruce's post. I'll share more on last year later, but it was a great success. This year I'm tripling the number of SIPs, and trying some other new projects.

The greens, tomatoes, and peppers I planted last year were seedlings purchased from friends and farmers markets. This year I want to start more from seeds. I don't have a good south window to start seeds indoors, so I'm trying cold frames.

The idea is to trap heat in the SIP, warm the soil, and get the seeds a head start on the season - essentially a mini greenhouse. Ideally, the frame will help the seeds germinate weeks earlier, boosting the harvest.

I'll still plant seedlings around May 15th (the estimated date of our last frost in Chicago), but this year I'm going to start some seeds at the beginning of April using the cold frames. If they perform well, next year I may start some earlier, and will certainly start more seeds (and purchase fewer seedlings).

The cold frames will also help at the end of the season, allowing roots and greens to produce a bit longer than they would otherwise.

The Design

There are countless ways to make these - I used this design because it fit perfectly on the frames I built around my SIPs, and I had most the parts left over from other projects. Because this is a test run, I made them easy to disassemble should I decide to change the design.

The top is a thin acrylic sheet, though anything that will let light through will work. They're held to the 2x4 frame with some L-brackets. I am considering sealing the edges of the acrylic with some silicone, though I'm not sure if that's necessary or will help significantly.

If you want to make this design more effective, add a 10+ degree slope facing south to increase the sun they capture. Integrating an automatic vent will significantly reduce the time spent monitoring the box temperature.

How it's working

I thought I would measure the effect the cold frame is having on the soil temperature. It's definitely going up during the day, which I assume will get the seeds moving along. The temperatures drop in the evenings, so I'm planning to cover the SIPs any night that will get close to or below freezing.

Around 5 pm Tuesday (a cool but sunny day),
the soil temperature in the SIP with a cold frame was 62, and

47 degrees in the SIP without a cold frame.

By the next morning, around 6 a.m. (an evening that dropped to the low 40s), the soil temperatures were: 48 & 42.