How can I turn my backyard into a new vegetable garden?


I am looking to turn an open area in my backyard into a new vegetable/cut flower garden. It is currently grass and blueberries that haven’t produced fruit in years and have been being mowed back a few time a year most years. I know I need to do a soil test (and am planning to do one soon) but am expecting the soil to be acidic and very lacking in organic matter. It is very sandy soil. I know a soil test can help get better guidance but I’m wondering if I can improve the soil and outcompete the existing grass and blueberry plants over this summer using cover crops and have decent soil for growing crops next year? I’m thinking an early spring planting of field peas and oats, then a couple crops of buckwheat and then a fall crop of peas/oats. I’d rather not till but am thinking I may need an initial till to get the first cover crop planted. Can you provide any advice on use of cover crops, tilling, local places to purchase cover crop seeds, how early cover crops can be planted, and any other helpful input? Also, I’m hesitant to bring in many soil amendments like compost and manure due to potential contaminants like herbicide residue and PFAS which is why I’m looking at cover crops.


Jonathan Foster, Home Horticulture Outreach Professional

If you are looking at converting a grass and shrub spot to an in-ground garden, and you are avoiding compost and manure, cover crops and green manure are your best option. I will say that it would be easier to construct raised beds in the spot, which have many benefits including better control over your medium, easier irrigation and erosion control, earlier thaw in spring, and better ergonomics… but you would probably have to purchase soil and compost to get started. For your reference and consideration, I will call your attention to our UMaine Cooperative Extension video series on using raised beds and our sample plan for building them. It would be a trade off for you, given your parameters, but it would much quicker and easier path to vegetable gardening on the site, and it can be done responsibly and with an eye toward not introducing unwanted chemicals to your property.

However, if that’s still not on the table, let’s talk about breaking ground and then using cover crops/green manure to condition your soil. You will probably need to get the area tilled eventually, but before that you need to remove the blueberries and grass. The former might be renovated or transplanted to a more productive spot, so I encourage you to explore those possibilities rather than disposing of them. Blueberries in the garden are nice–please see UMaine Cooperative Extension Bulletin #2073, Growing Wild Blueberries at Home and UMaine Cooperative Extension Bulletin #2253, Growing Highbush Blueberries. To remove grass, you have to kill it off first. It’s a large organism that includes both the above ground portions and an extensive fibrous network of roots, and it will resprout from any leftover living parts. Please see this UMD Extension page on removing turfgrass –you will be smothering primarily and then removing what’s left or (if you’re certain it’s dead, tilling it under).

As far as choosing cover crops and green manures and picking planting times, I have a few resources for you:

UMaine Cooperative Extension page on Covercrops for Maine Gardens

UMaine Cooperative Extension page on Selected Green Manures and Cover Crops

MOFGA’s page on Green Manures and Cover Crops

UMaine Cooperative Extension Bulletin #1170 Cover Cropping for Success (more commercially oriented but great information)

I will note that it would take quite a bit of effort to complete this season and be ready for planting non-cover crops next season. Overseeding existing grass with cover crops is not going to give you the results you’re looking for (grass is a pretty fierce competitor when established), so you’ll need to do this part before you can even get to your cover crops. If you’re committed, I would start smothering the grass now, then remove it and get the site tilled in time to put in a summer or fall cover crop. You may not have the fertility or texture you’re looking for by Spring 2025, but you could evaluate at that point. I do recommend getting that soil test you mentioned–it’s highly advisable to know what your soil conditions and nutrition are before planting anything or amending the soil. The UMaine Soil Analytical Lab can send you a kit by mail, if you request it on their site, or you can pick up a kit in any County office.

Finally, you should be able to purchase many different kinds of cover crop seeds at any local nursery or farm supply store, and possibly box store garden centers.