soil content for new raised vegetable bed?

[rosiegirl]

I came here recently about my first huge gardening mistake (killing all my seedlings!) and everyone was so helpful that I'm back with one more big question.

the area of our backyard that we dug up and prepped for a vegetable garden was in full sun in early spring, but in later spring it seems to be in the sun for only about 3 hours a day, which is clearly not enough!

so 2 days ago, we decided to build a raised vegetable bed in the sunniest part of the backyard. it's 4x10, and about 12 inches deep.

we're growing tomatoes, summer squash and cucumbers.

the big question is, what to fill it with?! we have a whole lot of compost (a pile sitting in our driveway!) and some bags of potting soil. if we put it all in, it would be about 20% potting soil, 80% compost.


1. does that sound totally off? should we be getting some top soil or more potting soil? what is the best soil composition?

2. after we add all the soil and compost, do I need to water the bed before I plant?

thanks!

[farmerlon]

we have a whole lot of compost (a pile sitting in our driveway!) and some bags of potting soil. if we put it all in, it would be about 20% potting soil, 80% compost.

Personally, I think that will probably work just fine; especially if the compost is of good quality (finished).
I see people build Lasagna garden beds with a lot of materials that are not even "broken down" yet... so, their beds will be "composting" some while the veggies are growing.
If your compost tends to be a bit Acid (lots of leaves and/or pine), you might need to sprinkle in some Lime.

I would water after you plant... not before.

[rosiegirl]

thanks!

do you think we should add some topsoil to the top of the bed after the potting soil and compost go in?

[engineeredgarden]

Your mixture will do just fine. I have several raised beds that are filled at least 50% of the way with composted manure, and they do great. You'll be glad you made the bed 12" deep, because it'll require less watering, and also keep taller plants from falling over later. I don't feel top soil will be necessary....

EG

[tedln]

Rosie,

It really depends on the quality of the compost. You said it is in your driveway. I think that means you purchased a load and that is where they dumped it. If it is compost from a municipal or city composting center, it is probably 90% chopped up wood that sat in a pile for a year. It will probably be very low in nitrogen. It also will deplete nitrogen from topsoil as it continues to decompose. If you purchased a load from a nursery supply place, it is probably good compost. They probably use it themselves. You should be able to plant directly into the good compost. The not so good compost would probably work best if mixed with some good topsoil and extra nitrogen added to the mix. Just guessing about what you have.

Ted

[rosiegirl]

tedln...thanks! it's compost from a gardening center and it's what they use, so I imagine it's good stuff.


I'm glad we can just plant right into the compost without topsoil, saves a trip and some money!

[BrPanthers99]

I go with about 1/3 peet moss and 2/3 Scots Topsoil. Makes a great combo which I have had alot of success with.

[farmerlon]

I'm glad we can just plant right into the compost without topsoil

Yes, because you have to be careful with "Topsoil" too. Unless you know the source (contents and quality) of the topsoil, it could do a lot more harm than good.

[garden5]

I'm glad we can just plant right into the compost without topsoil

Yes, because you have to be careful with "Topsoil" too. Unless you know the source (contents and quality) of the topsoil, it could do a lot more harm than good.

That's true. One good example of this is topsoil that has a lot of junk in it. Not only rocks, but also pieces of brick, glass, and asphalt. You have to be just as diligent about where your topsoil comes from as where your compost comes from. It does sound like you got some pretty good compost, though.