having taught people to garden for years, many people want to know how to prepare their soil so they can start a vegetable garden. if you talk to people who have been growing for years, you’ll notice they spend a lot of time building the soil in their garden beds.
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for first time gardeners i always recommend to start small and because each patch of dirt is different, i recommend starting with a raised beds, which is nothing more than building a bed of soil on top of the ground instead of in it. you can add sides made out of wood, edging or other materials as a side wall, but it isn’t required, mounded dirt works just as well if you’re on a budget.
building a raised bed frame
for most people they want to have the tidy look of a wooden frame and it can be done quickly for little money. start with three 2×6’s and cut one of them in half. this will form the four sides of the bed and create a bed that is 4 feet wide by 8 feet long.
this is an ideal size because it minimizes the number of cuts (pro tip: big box stores will cut it for free for you) and at four feet, you can reach to the middle from either side without having to stretch too much. a few screws will make a solid frame for you to fill in the dirt with.
turn the soil below
even though we are going to build a bed above the ground, we want to break up the soil below it so that our plant’s roots have an easier time of penetrating the ground as they grow. ideally you would shovel off the top layer if it is grass, but i’ve done it both ways. removing the grass below will help reduce weeds coming up later, so it’s often worth the effort.
if the soil is pretty bare, what i’ll do is rake the top then go buy a gallon jug of white vinegar to douse the little bits of weeds or grass with the vinegar to kill a few days before i build my bed. white vinegar will work well to kill the weeds in spot treatments, but if you have more than 10% coverage, i’d just scrape the top off completely.
the last part is take a “digging fork” and just break up the top few inches of soil, it can be pretty chunky because we’re going to cover it all with our soil bed mix soon anyway. don’t get too tied up in making it perfect, this is a really a rough pass that we do quickly and move on.
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mixing the perfect soil to grow in
first off, there are many different options here and if you ask 100 people you’ll get 101 recommendations. so understand that if someone uses something different, that’s fine. for most people just starting out i try to make it really simple and we can get into more of the nuances later. so use this mix to start and in a few years, start to try different things. we want to get you to gardening as quickly as we can and if you get caught up in what mix is the best, you’ll never actually start gardening.
so i use a mix of compost, vermiculite, and peat moss. typically i buy for a single 4 foot by 8 foot bed that’s around 6 inches deep the following:
- 10 bags of compost (one cubic foot size bags)
- 1 bale of compressed peat moss (three cubic feet size)
- 1 bag of vermiculite (2 cubic foot sized bags).
- 1 small bag of bone meal
- 1 small bag of blood meal
if you don’t know what these are, just print this post off and bring it with you to any big box store, they’ll know exactly what you need from this list. if the employee doesn’t know these items, it’s best to find someone else because these are gardening 101 supplies.
for compost you’ll find a lot of different options, my favorite is “mushroom compost” which you can find bags at any big box hardware store. a close second is “black kow” compost. i’ll often grab a few of each to make up my 10 bags for my bed.
if you can’t find these specific ones, it really isn’t a big deal, use whatever compost you can find at your local store or garden center. compost provides a lot of nutrients to your plants and serves as the base for seeds to root into.
vermiculite is essentially rock dust crushed up, it provides a lot of minerals for your plants, but it’s main function is to act like a sponge for water. be sure not to get confused with perlite, it’s not the same. this one might take some calling around to find, if there is a local gardening group they might have some good leads.
i will also add a note here that if you start searching around about vermiculite, you’ll inevitably run into an old timer that will make the point about asbestos in vermiculite. this is something that we had to worry about 40 years ago, but today there is no source allowed in the usa or canada that doesn’t carefully screen and test for this. the myth still persists today, but you should have zero concerns because the industry has long made changes to prevent this.
often garden centers or seed/farm supply places carry it. i’ve even seen it in small bags at your big box hardware stores. if you can’t find it consider purchasing a few bags off of amazon, while it’s a bit more expensive locally, you can buy a few of these bags of vermiculite and be good for a 4×8 bed.
the last part of the soil mix. this fluffs up the soil, allows for good oxygen infiltration and also acts like a sponge to hold in moisture until plants need it. this can be found anywhere and they type or brand doesn’t matter. the only thing i’ll suggest is make sure you get it from the soils section where you’d find your bags of compost or near the bags of mulch section. sometimes they sell small bags that are meant for growing orchids, these are often expensive, but the ones in the bagged compost section is usually sold “compressed” for very cheap ($10-$20 for 3 cubic feet compressed).
a common question that comes up around peat moss are concerns about if peat moss is sustainable. it is true that 10 years ago peat moss was harvested from natural wet lands, but today it is done in a manner that is regenerative. if you are still concerned, consider sourcing coconut coir which is a material similar to peat moss but made from the waste product of coconut husks. in the end, i suggest you don’t get too caught up in your first year or so, just get your first year under your belt and then work on improving in later years.
bone and blood meal
i prefer to use bone meal and blood meal, but there are many options. obviously from their names, they are a animal sourced product. those wanting a non-animal source can try seaweed meal or fertilize, you can buy seaweed fertilizer here. bone and blood meal are organic sources of the major nutrient (npk: nitrogen, phosphorus, and potassium).
since we are starting out with such good ingredients, we don’t need much of these. if we were starting with the soil in ground, there may be need for more as directed from a soil test, but since we are building our own soil we don’t need a soil test for our first year or two. i start out with one large handful of each, mixed evenly across the whole 4×8 raised bed.
mixing it all together
some people will use a tarp to mix the soil together, i just skip that and dump everything in a pile in the framed bed, then mix with my hands or a shovel. if you choose compost that is moist, but not sopping wet it will mix easier. sometimes this means pulling off the top few bags at the garden supply place so you get to a lower layer of bags that haven’t soaked up any recent rain.
here is my basic approach:
- take your peat moss bale and place it in the bed
- with a shovel stab the plastic in a line to break open the bale
- turn it over to dump the peat on the ground and remove the plastic
- shake out half your vermiculite on top of the peat moss, set the rest aside
- grab one large handful each of bone meal and blood meal, sprinkle across the bed
- place a bag of compost in the bed, stab with shovel to dump on the pile
- repeat with compost about half your bags
- using the shovel and hands, mix it all up until it’s well mixed
- add remaining materials and mix it all up
- smooth out the top and give the soil a brief water
how to water your garden
you want to water it a few days before you plant if you can, this will let all the water to absorb into the peat moss and vermiculite. water for a count of five and then stop. again, counting to five, if the water fully absorbs into the soil so there is no sheen on the dirt from the water, water again for a count of five. repeat counting to five until the water doesn’t absorb all the way in five seconds. this is a good indicator that the soil is nicely saturated with moisture, but not soaking.
in the end building your soil will set you up for success for years to come. following this formula and starting small, you will have a better drastically easier time because we’re not trying to fix our existing soil or battle weeds. start with one 4×8 bed, then next year go a little bigger. the number one thing i see is new gardeners burning out their first year because they took on too big of a garden.
- what are your garden plans this year?
- what tips have you learned?