Soil For Raised Bed?

Due to extremely poor drainage in my garden (and after finding out the hard way, when rainy season came), I've decided to build raised beds for next year's garden.

I just read an article written by a professional grower that blasted Miracle Grow Garden Soil, and chemical fertilizers in general. This grower said that every plant he ever planted in this soil eventually died.

The same article also ripped the $1.00 bags of 40 pound top soil sold at home improvement stores, saying there were no nutrients in it.

The grower recommended buying "professional" soil.

So what is professional soil? Where do I buy it? What soil should I use for my raised beds? Even if I started composting now, I would only get a fraction of what I needed for my garden, in the Spring.

The same stores that sell the $1.00 bags of top soil also sell humus,manure, peat moss, etc. Can I make a nutritient soil by mixing these ingredients?

Your ideas?

Here's a link to the article, by the way:
http://mgonline.com/fertilize.html



This message was edited Oct 5, 2005 11:32 PM

I believe the most valuable asset you have for gardening is your native soil. It takes 500 years or more for Ma Nature to create an inch of it and to bury it or replace it with purchased products is wasteful and unnecessary. I don't know what "professional soil" is or why you would need it. Experts and "method" hucksters like the Square Foot guy are always more than willing to spend your money while ignoring your soil.

Some areas are blessed with more soil than others, some soils drain better and some hold its nutrients better. But every soil can be improved and unless your soil has suffered a chemical spill or some similar catastrophe, your efforts would be better spent building it up with inexpensive or free organic matter.

I'd recommend double digging the raised beds. Remove a strip of soil 12" deep and 12" wide across the bed. Use a fork to loosen the soil below another 12" or so. Don't turn the lower 12", just push the fork in as deeply as you can and rock it a bit. Then moving up the bed, move the next 12" strip of topsoil onto the soil you just loosened and loosen the lower 12" in that trench and so on. Dig a few inches of soil out of paths and add it to the growing beds. It sounds like a lot more work than it is. Do a little at a time and by spring you will have have well drained, loose and rich soil at little or no cost other than some rewarding labor. Keep the soil fed with mulch and compost, don't walk on it and you may never have to re-dig that bed again; or at least for a number of years.

If double digging in your soil is too much work, then work the soil as deeply as you can, but it may not break up the conditions that cause the poor drainage.

To fortify the soil, use any type of organic matter that you can find. Stables are often happy to have gardeners haul away free horse manure. (Some happy enough to be rid of it they'll deliver it.) Utility and tree trimming companies will often deliver a truck load of wood chips for free or at a nominal cost. Leaves and grass clippings are free for the hauling from tidy homeowners' yards. Adding any or all of these material plus coffee grounds, kitchen waste and your own yard waste will provide all the nutrients that you need for productive beds this spring.

Wayne

For a quick solution that's not quite as labor intensive (I did this when very pregnant), you could call some local nurseries. They sometimes carry nice local soil, and are often willing to mix it with compost. We got a truckload that I tested and it was both toxin-free and loaded with nutrients. I filled a 4 x 32 bed with it after removing the sod and broadforking (adk's description above) the bed deeply. Everything flourished. Meanwhile we composted the sod layer I removed to make the bed and next year will use that to top things off. Over the winter we fortify with all the leaves I can gather, grass clippings, hay, old mulch, whatever. Good worm food to get the little creatures up and working in early Spring.

Professional soil? I've never heard that term before. When I was working in the lab at university, all the researchers used a growth medium called 'Redi-Earth' when growing plants indoors. It looks like soil, but it doesn't actually contain any soil at all. Since the researchers were professional agrologists, perhaps that is what is meant by professional soil. However, those people doing field research just planted things directly into the ordinary soil outdoors.

I would agree with the person who said to call a local nursery. After all, they are likely professionals :) Not only are they likely to have some decent soils / growth mediums, but they should be able to give you advice on what is best to use in your particular climate.

When we were rank beginners, years ago, we made our first "raised" bed. My yard (my whole street) is on a hill: each yard has a sheer slope on both the down-hill and up-hill sides. When my up-the-hill neighbor put in an in-ground sprinkler system, I could see sprinkles falling on my lawn. "A ha!" I said to myself, "he's watering our yard." After asking nicely whether he minded, I had DH build a retaining wall on our property to the height of his property (4' of wall buried 1' deep). Basically we had 3' by 8' by 5' totally empty wedge. We put top soil, loam, bags of manure (dry from HD or somewhere), nothing organic - we hadn't weren't smart enough to put grass clippings leaves or anything similar in there. Lots of water as we filled it. Almost everything we put in there thrives, so much so that we call it the ICU! If a potted annual isn't happy, we stick it into the wall garden instead. (Otherwise, it's a perennial bed. So far.)

I don't remember the exact proportions, but again ask a local nursery [not HD]; that's where we got ours from.

I grow lots of stuff in raised beds for bonsai. My garden soil is wonderful & alive, but I did the raised beds so I could insure good drainage for the pines and junipers and so lifting the plants when ready for pots wasn't so difficult. Here is what I did:

I built 5 - 4x8 beds that were 7 inches high from treated 4x4s. For the soil, I used :

3 bags (2 cu ft) pine bark fines
1 bale 1-1/2 cu ft Canada sphagnum peat
1-1/2 bags Turface (a hi-fired clay granule, almost like porous ceramic)
1 bag coarse sand
1 bag crushed granite (chicken grit)
You could add composted manure if you like, as this soil is weak on micro-nutrients, but don't waste money on the bagged stuff at stores. I added Schultz micro-max, a granule form micro-nutrient supplement (no weeds, as in manure).

The photo is the soil today, at the end of the 5th growing season. Drainage is superb, root health is amazing, water, nutrient, and air holding ability is great. There are no problems with the soil becoming hydrophobic unless you allow it to dry completely. Workability is excellent as the soil has good loft & will not compact. Plantings in the raised beds have all showed much better vigor than plantings in native soil. The worms are loving it. After 5 years, there is little noticeable shrinkage. As it eventually occurs, I'll just add bark and peat to compensate for particulate breakdown.

When using this soil, the first growing season will require frequent additions of a high nitrogen content fertilizer. In subsequent years, I have used only topdressings of Milorganite to keep plantings healthy/happy. If you wish additional photos of the beds and plants in them, or have additional questions, let me know. Hope this helps.

Al