Soil For Raised Bed Vegetable Gardens
February 25, 2018 | | Vegetables
“What kind of soil should I put in my raised beds?” our customers ask. This is one of the topics that will be covered in our upcoming program for inexperienced vegetable gardeners on March 11th. Raised beds are one method of growing vegetables, and in areas like Cape Cod where the soil is often sandy, it’s a way to quickly provide a layer of loose, organically rich soil that sits on top of the native soil.
Here are a few tips for starting out with raised beds:
- Whether you have sand or clay, turn the native soil either before constructing the raised beds or before filling them. If the area was lawn, turn the turf right into the ground. You can turn the soil down about 10″ with a shovel or tiller.
- After the ground is tilled, fill your beds on top of this loosened ground. Do not put a layer of plastic, landscape fabric or other material on top of the native ground before filling unless your raised beds are a good 3 feet high. Your plants will benefit from having deep soil to sink their roots in.
- Fill your beds with a combination of loam and compost – use more loam than organic matter. A ratio of 3/4 parts loam to 1/4 part compost is fine, but more compost is not a good thing.
- Do not fill beds with potting soil, although over time if you want to empty pots that were filled with potting soil into the raised bed that’s fine. Potting “soil” is actually a mix of peat moss, vermiculite, and some other organics such as bark, compost etc. This isn’t bad for your beds, but it’s too light to be used alone for growing veggies.
- Do not use pure peat moss. Do not fill with pure compost.
- You can use bulk loam and compost, or bagged loam and compost, depending on the size of your beds and your budget. If you have your own homemade compost, that is great too. Composted manure can be used in place of other compost.
- Fill the beds so that the soil/compost mix comes to the top of the raised bed. It will settle and sink at least 2 inches in the next two years, so if you use less you’ll end up with beds that don’t contain enough soil.
- Once beds are filled, rake to smooth the contents but don’t step on the soil or tamp it down in any fashion. Let the rainfall and your watering settle the contents without pressing out air spaces. Remember that the roots of your plants need soil, organic matter, water and air.
These are the high raised beds we sell at Country Garden. This tall version is perfect for people who can’t bend over well or get down on hands and knees. Here you see how the bed looked when first planted in early June. We filled
And here is how that bed looked in early September! I took this photo when I was clearing out any plants that were finished, and pulling a couple random weeds. Although raised beds have fewer weeds than the native ground, you will find them hiding among your veggies so be on the lookout. Nature always finds a way to blow some weed seeds into good, fertile soil!
When your raised beds are very shallow, be sure to till the native soil underneath them so that the roots of your plants can grow down into the ground. If your beds will be as shallow as these, amend the native soil with compost or composted manure before tilling or turning it, then fill the beds on top of that amended area.
Posts navigation
Subscribe To Our Newsletter
Sign up for our weekly email about sales and events.
Please enter a valid email address.
Something went wrong. Please check your entries and try again.
Vegetable gardening is all about finding the right balance of sun, water, fertilizer, and, perhaps most importantly, soil. Not soil is are created equal, however. Whether acidic or alkaline, the right gardening soil is almost always going to contain a host of nutrients to help bolster the strength of your plants or veggies. In the end, the recipe for the best soil for vegetable gardens is all about understanding the basics behind what works and what does not.
Article continues below advertisement
When it comes to vegetables, each one seems to have a different soil preference, which makes it difficult to generalize any one type of soil as “the best.” Nevertheless, there are certain soil properties that delineate it as either fallow or arable. According to Gardening Know How, good soil should contain organic matter and a combination of nitrogen, phosphorous, and potassium.
Source: Getty Images
Article continues below advertisement
Fertilizer and compost
Organic material provides nutrients for garden vegetables to feed off of and softens the soil so that plant roots can spread more easily. This softening effect also makes the soil more spongelike, making it easier for it to retain water. Most fertilizers will provide this organic matter, but compost is usually your best bet. True compost, that is compost that has been cultivated with the proper amount of nitrogen and carbon-rich ingredients, is a boon to garden vegetable soil.
The best part is, making compost at home is easy and eco-friendly. It will also cost you nothing except maybe space and a few extra minutes of time a week. The best compost includes five elements. The first is a selection of browns, or carbon-rich things like dry grass, newspaper, and leaves. The second is greens, such as vegetable scraps, coffee grounds, and eggshells. Then some moisture, aeration, and time are required to help the aerobic bacteria grow.
Article continues below advertisement
Soil pH
Soil PH is also important for vegetables. Exact pH requirements vary across the board between alkaline (high pH) and acidic (low pH), but most garden veggies prefer a pH of about 6 or 7, according to Gardening Know How. The best way to know what type of soil you have is to test it. You can do this professionally or get a test kit online.
Source: Getty Images
Article continues below advertisement
The best soil for a raised bed vegetable garden
Not all gardens are created equal and that means that not all soil requirements for those gardens are the same. For instance, raised bed gardens actually do better when you mix specific types of soil. According to Love to Know, this blend should be a 50:50 mix of compost and local topsoil, preferably cultivated from your own yard. Pre-mixed soil blends won’t have enough nutrients.
Source: Getty Images
Article continues below advertisement
The best soil for potted vegetable plants
Those who don’t have space for a backyard or raised vegetable garden might find themselves growing veggies in pots, often indoors. Even in this situation, however, a bag of premade potting mix is still going to be secondary to compost and natural soil. The thing is, you don’t often have access to a lot of local soil. If this is the case, Plantophiles recommends purchasing a potting mix made from compost, peat moss, bark chips, and pine bark.
These elements should create a baseline pH for most vegetables to thrive, as well. The other downside of potted soil is that it loses the added aeration and verimular activity of things like earthworms, which help make garden soil that much more nutritious for your veggies.
If you lack the compost to start and need a little push to get the soil to the right state, don’t be afraid to look for a commercially-available bag of garden or potting soil. The truth is, whether you’re growing veggies in a pot, a raised bed, or in the ground, you can usually get away with adding an extra bag or two of those store-bought mixes. Just remember to choose ones with the least amount of synthetic elements.