Protecting Garden Plants from Frost

I am trying to buy as little as possible and garden.  Since I am a novice, particularly with the climate change in Japan (everyone is a novice there), I am unsure if what I am doing will work.

I see that the farmers around here use nets to protect their plants from frost.  I don't have nets, but we have plenty of branches from pruning trees.  I am using the branches and their leave to protect my plants from frost.

I know that this photo looks like a pile of garbage.  Actually, I am impovising ways to protect my broccoli and cabbage.  You can see the daikon seedlings in the foreground.  

This looks like a collection of garbage bags too, and that is what it is.  I have braced the sides with pruned branches.  Some stuffing from a blanket is going to be thrown away, but first it is being use to protect my seedling.  Probably it is going to be too cold to grow these plants, but in the spring time, I will be ready to plant.  One bag contains wheat grass seedlings and I am hopeful for them.  They seem very hardy.