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ani_t

Making a raised bed with just compost ?

ani_t
13 years ago

The earth around my house is impossible to dig into . I triedvery hard but its nothing but fill dirt it appears. So I 've decided to make raised beds all around.

Is it possible to make raised beds with just compost ? Do I need to have them deliver topsoil AND compost ?

Also does anyone have any idea about which companies around here do blower trucks for compost and what the minimums are ?

thanks

Shashi

Comments (14)

  • pdxfarmer
    13 years ago

    Steve Solomon, a regional expert, says only use the minimal compost necessary. More than necessary encourages symphylans,a pest that he claims is very problematic. This is not from personal experience, but his book called Gardening West of the Cascades. It's a great read, he's a little dogmatic so don't let him push his ideas too hard. good luck with your projects.

    On a side note I have seen pictures of people garden successfully in bales of hay, might be something to look into if you don't mind the aesthetic.

  • gardengal48 (PNW Z8/9)
    13 years ago

    In addition to the above, the other problem you will have deal with is shrinkage. Compost, even 'finished' compost, will continue to decompose and breakdown and as it does so, the volume will decrease, sometimes dramatically. You should expect a reduction in volume anywhere from 1/3 to 1/2 during the course of the growing season. This may not be an issue if you are growing single season plants, like annuals or most veggies, but it can be a problem if you are considering more permanent landscape plantings.

    The other issue is compaction. As compost breaks down into smaller and smaller particles over time, the pore space (space between the particles) also reduces, as the smaller particles fill up these spaces. Lack of pore space reduces the amount of oxygen available and impacts drainage. You could end up with a raised bed that drains no better than your hard-to-dig-in soil.

    And depending on the compost and how well 'aged' it is, it may be too rich or "hot" for tender seedlings.

    Compost is just organic matter, not really soil. And there are recommended limits on the amount of organic matter this is considered appropriate or even advised in a typical planting situation. The rule of thumb is no more than 25% organic matter, with 10-15% being a target level.

    Plants will grow under all sorts of strange planting situations but they do not always provide optimum results. And what works for temporary crops or for a short period of time may not provide equally satisfactory results long term. Personally, I'd choose a 3-1 mix of topsoil to compost or even better, a garden soil mix (sometimes referred to as a 3- or 5-way planting mix) that already has a component of compost or other organic matter included.

    Pacific Topsoils has blower services, as does Cedar Grove Compost.

  • PRO
    George Three LLC
    13 years ago

    have you tried a digging bar of some sort? i have an 18lb pinch point bar that i refuse to believe cant get thru your soil.

    anyway, i think they are like $20, $30 at harbor freight. its one of my favorite tools. cuts through roots, breaks up rocks in the soil. breaks up concrete. can lever a ton of weight.

    Here is a link that might be useful: pinch point bar

  • jean001
    13 years ago

    If your soil is too hard to dig, it's too dry.

    At the correct moisture content for digging and planting, you should be able to grasp a handful. Then squeeze firmly and release. Moisture content is just right if the molded "ball" breaks when nudged with a finger.

    After you dig, mix in at least 2 inches of compost.
    Repeat every planting season.

  • Embothrium
    13 years ago

    If you're going to have raised beds anyway just buy good topsoil, dump it on top of the hard ground and plant - without mixing the two together.

  • ani_t
    Original Author
    11 years ago

    I like the idea of not digging. I am sure the pich point would do the job but I probably couldn't!
    I am going to do this: please provide and corrections for blunders I am about to embark on ...
    1. Put down cardboard or burlap . I am not sure where to get so much cardboard
    2. Build a square with blocks
    3. Place a perforated PVC pipe with ends sticking out with elbows for bottom watering and aeration
    4. Fill with dark bark fines and peat perlite like 511 mix
    5. Plant hostas and other plants that can live with dappled sun
    6. Water from the bottom through the tubes or from the top.
    If there was an easy way to covert this into a wicking bed I would love to hear it. This location will probably need some watering since its almost shaded by trees ...

  • charleney
    11 years ago

    Local hardware store gives me all the cardboard I can use! I once ran out of potting soil and compost. Planted a rose bush in straight (store bought) compost. Rose went nuts and was fantastic in a big pot. I would do it! But then I' lasagne garden'. Good Luck!

  • tanowicki
    11 years ago

    Do you have a lot of weeds or grass? If not, you can skip the step 1. I wouldn't use the burlap but would stick with the cardboard.

  • PRO
    George Three LLC
    11 years ago

    it all seems so overcomplicated to me. i would rather have a plant or two fail or struggle for a year or two.

    if you are trying to kill grass and only applying 6" or so of soil on top, i would put down some barrier. but i would just go with newspaper. something that breaks down very quickly. if you are putting a foot or more of material on top of grass, i would skip the barrier. just deal with weeds that come up.

    so my plan would be:

    1. edge the bed with whatever. wood/rocks/blocks. I would go with broken up basalt for as cheap as possible (free off craigslist, delivered or whatever).

    2. fill with good topsoil.

    3. plant plants.

    4. water.

    perhaps not optimal, but very easy!

  • ian_wa
    11 years ago

    Still too complicated. Here's my plan:
    1. Plant shade plants/perennials in existing soil
    2. top dress with about 4" of compost... maybe 6" if it looks like it will settle a lot
    3. DONE - but plan on watering as needed. If you don't like watering by hand with a hose, put a soaker hose just under the surface of the mulch as you are putting it down.

  • dottyinduncan
    11 years ago

    Ani, have you checked the soil, compost, mulch forum here on Garden Web? They are great believers in building up, rather than in the ground, especially when you have poor soil such as you describe. I think straight compost is wrong. My compost is so light it dries out too quickly. I like the lasagna beds, using materials that are easy to get and cheap, topped off with purchased top soil and your compost. I've done this, planted in it right away and had amazing results. You always wonder what the developers do with the good native top soil. It always seems to disappear. Good luck

  • botann
    11 years ago

    Some developers sell it to the topsoil people who sell it back to the developer or homeowner. In some cases they strip the soil right down to hardpan before the house is built.
    Then the builder subcontracts out the front yard landscaping, leaving just enough money for a cosmetic coating of topsoil. That's not always the case, but it happens more often than naught.
    Mike

  • oliveoyl3
    11 years ago

    It depends on what plants you want to grow & how much time you have to gather materials to layer for sheet composting prior to planting transplants aka lasagna gardening.

    I've layered up for perennials and shrubs making mounded beds with lots of compost + ingredients in both sun and shade then mulched once the weather has warmed up the soils. The course stuff or manure goes on top of the existing soil or sod covered with cardboard, then I add ingredients to top with finished compost if I have it. Unfinished if that's all I have available. These beds tend to stay more moist with all that compost, so you have to be careful not to tuck them in with mulch if planting in our wet spring season. It just doesn't drain so well especially when it's chunky looking and there are pockets for water to collect. The rains tend to wash it down and make smooth, so I've learned to let it stay chunky & don't dig too much during the wet spring weather. Once summer comes you will want to water in well and apply mulch as you plant each plant or section of the garden.

    I usually put the plants in the garden where I want them to go then when I had a spare moment that week pull my garden cart out to the garden preloaded with mulch, compost & shovel. That worked well when I was expanding a lot of garden space & still works today when I just tuck a few things in here & there filling holes or moving plants around. If I put them out in the garden space & we have sunny weather I put labels there to mark their places nd group the pots back together in my cart or another spot for watering until I can get them planting during overcast or light drizzle days.

    For vegetables and perennial fruits as well as herbs I have found by trial and error that I prefer to turn that top layer of composted materials over and remove rocks. I may not do it the 1st year after planting through the layers, but I will in the fall or early spring if the soil isn't too wet. I prefer a smooth soil for seeds and small transplants, so turn it over, add granular organic fertilizer and rake a bit to prepare for planting. I may plant that same day or weeks later.

    After years of keeping a mulched garden I have very few weeds. In areas where I've worked other gardens with lots of existing weed seeds it has worked to lightly rake a bit every week or so after preparing the soil by double digging or just use weed free mulch as a 2-4 inch layer like icing on a cake & plant right through. Every time you dig through that weed free mulch you pull up weed seeds, so reapply some mulch over it again to prevent germination. I've built several gardens that way with minimal work afterward except for slug control and monthly patrols to pull out the little seedlings that sprout. Mulch surely helps reduce the workload as I maintain several areas at our camp this way. What doesn't work is constant cultivation in new gardens because that brings up the weed seeds again.

    Hope that helps ...

  • botann
    11 years ago

    Yup, the more you disturb the soil and don't use a mulch the more you get quick to go to seed weed. Shotweed and Chickweed come to mind first. The weedy Oxalis and that hardy Geranium Herb Robert comes in a close second.
    Mulches work. Use them.
    Mike