Soil for raised bed?

[Rivian]

New raised bed, 70cm high. Does it really matter whats in the bottom half? It doesnt rain a lot here, we can go a month or two without significant rain. Except in Winter when its not needed.
And what to put in the top half? Cheap-ish, if possible
Have just few trees for it right now, so what I dont need for bonsai I will fill with veg until then

 

[Wires_Guy_wires]

Coco coir, perlite, pumice and wood chips.
Good for most root systems, drains OK, degrades over 3-4 years.

 

[Rivian]

I am watching a vid on Hügelkultur right now. I have some low quality logs lying around, tempted to try this unless someone warns me of adverse effects. Could the fungus in them hurt my plants? I can also get Rhine-sand and loam(?) for cheap. Also self-made charcoal, and some grass clippings in the bottom half for nitrogen.
The bed is a bit large for coco coir but overall that seems like a decent suggestion

 

[Treefer]

My DIL starts with hardware cloth on the ground to block burrowing critters. Then half way with cuttings, sticks, leaves, mulch, etc. Top gets raised bed soil.

 

[Rivian]

Lets play a game, guess what the frame cost. Normal raised bed size and 70cm high. Good quality wood because the dumbo that bought it didnt care to ask the price.

 

[hampton]

Lets play a game, guess what the frame cost. Normal raised bed size and 70cm high. Good quality wood because the dumbo that bought it didnt care to ask the price.

I’ll take a stab - $250. That’s based on using ground contact lumber with a 3’x6’x -30” (70cm)

I’m pricing out an automated watering system - it’s a bit more than I expected but I don’t know the prices are going down anytime soon and I need a project…

best
Zak

 

[ShadyStump]

I am watching a vid on Hügelkultur right now. I have some low quality logs lying around, tempted to try this unless someone warns me of adverse effects. Could the fungus in them hurt my plants? I can also get Rhine-sand and loam(?) for cheap. Also self-made charcoal, and some grass clippings in the bottom half for nitrogen.
The bed is a bit large for coco coir but overall that seems like a decent suggestion

I was about the suggest looking into this while reading, but you beat me to it. It really just means finding the organic material that turns into good soil and using that for filler. You can use any yard or lawn cuttings, anything you would through in a compost bin, then make sure the top foot/30cm is prepared soil. Because motorized tilling isn't really an option in raised beds, go with something heavy on mulch so the soil stays broken up and doesn't compact.
If you're using the raised bed for trees mostly, you might consider stone as filler to keep the roots from going too deep, but I don't suppose it would make too much of a difference if the trees are only there for a couple years at a time.

 

[Rivian]

$250

I wish.

 

[Cajunrider]

70 cm high is pretty tall. For me I would fill the first 30 cm with any non-weedy organic matter: logs, twigs, wood chips. The next 30 cm would be a mix of top soil and some composted manure.