Raised bed/Cold frame

Back in the spring I built my first traditional raised bed. It’s seven foot long, four foot deep and nearly four foot tall. I built it in an area that used to be a gravel driveway and wasn’t useable. A few weeks ago I decided to use it during the winter as well. As the sun drops underneath the bed gets eight hours of sun per day until March. I built a back wall with junk wood and roughed up insulation. On top of that I secured Mylar to increase the winter sun’s rays. I have 3ml greenhouse plastic to surround the rest but only when very cold. I figured red acre cabbage would be a good test since it’s cold hardy only to the mid twenties. The bed on top has ten inches of soil that I planted carrots in. Whether it works or not I’ll get back to you guys in a few months.

Can you tell us more about the mylar?  Looks cool!

It’s an 82X47 Inch sheet. It says the purpose was for greenhouse use. I put it up eight days ago and it’s holding up good. Got two sheets for 8 bucks. The sun still isn’t low enough for it to do much good.

So it's going to be a box under a box with stuff growing in it? Can't wait to see more on this!!

Yes sir. Figured I’d try to use a spot that wasn’t good for anything else.

Any chance you've ever tried that trick with manure for winter beds? I'd seen somewhere that as the manure breaks down it creates heat and was used to keep winter beds warm.

I haven’t tried it. I think this spot is too small for that. I will probably water it good prior to very cold temps since wet soil holds more heat.

Is there a definitive answer or way to grow veggies in winter in raised beds, 4x8x2ft, without grow lights or warming mats? (Mediterranean zone 9)
I’m confused, because I’m told it’s good to use hoops and agribon on the raised bed, but that will block a god portion the needed light ....?
Is one supposed to take off the agribon every day and put it back on for nights?

Would using old glass windows work better or are they simply not as insulating as microfiber agribon...?
I’m just condfuused by the amount of conflicting details and no in depth info. (I’m a veggie growing newbie tho, so that is likely to be inexperience talking)
Thank you 🙏

You may not need any protection depending on what you intend to grow. Zone nine has a bunch of options. Very little of the cabbage I planted germinated. Not wanting to mess with it further I put chard seed under the raised bed. The raised bed is loaded with small carrot plants. Unless it’s extremely cold I have no plans of protecting either of them. Zone nine is pretty much frost free. I imagine you could grow unprotected cabbage, spinach, lettuce, chard, carrots and probably many others.