Software
Houzz Logo Print
englishable

Rebuilding garden soil?

9 years ago

This was our second year cultivating a very large vegetable garden (7,000+ sq ft) after purchasing our home in 2015. It did amazingly well, overall, in 2016, but after getting everything planted this spring, I wasn't able to keep up with it (I was very pregnant this summer!) and my husband did the best he could on his own, but the weeds are out of control. We also noticed in both years that there are spots in the garden that do not do well - for example, in our row of cucumbers, only the few on the north end of the row grew well and as you moved south down the row, the plants got smaller and smaller. I'm not sure if this is an issue with the soil or something else.

So we are considering not putting in a garden next year and instead focusing on adding fertility and getting control of the weeds (mostly quack grass, some pigweed, and some purslane).

My idea is to till everything under in the next week or two, add some manure and plant a winter cover crop. In the spring (2018), till that in, add more manure, our compost and this fall's leaves and then plant a spring cover crop. Close to July, mow that down and then possibly cover the whole garden with black plastic and leaving it through the hottest part of summer and all winter. In spring 2019, remove the plastic, till again and plant our garden.

I've read conflicting information about using plastic, so I had some questions. Would soil solarization even be effective? We get a few 80+ days each summer, but it doesn't stay hot for weeks at a time or anything. Should we use black or clear plastic? If it doesn't get hot enough here for heat, using clear plastic, to kill the weeds, would blocking the sun with black plastic be a better idea? And should the plastic be permeable? Since it's such a large area, do we want to ensure water reaches the soil so we don't also end up killing the soil microbes and other beneficials? We want to increase fertility, not create a wasteland!

And if my whole plan is flawed - what would you do if you had a year to improve your soil and significantly reduce weeds?

Comments (14)

  • 9 years ago

    I would plant a winter cover crop now, followed by a summer cover crop, followed by another winter cover crop in a year, trying to maximize biomass and root channels. It is best to plant mixed CC. Specifically to reduce weeds, I would make sure there is squash or cowpeas or collards in the summer cover crops, which blot out the sun but which you can also eat, but at any rate it is a good idea to plant thickly. If you are using large seeds, you can, when you seed the CC, also spread some organic litter, such as ground leaves, if you have the stuff.

  • 9 years ago

    Before doing anything you should take a good look at what that soil needs. A soil test for soil pH and major nutrient levels is a good first step and now is the time to do that. These simple soil tests will compliment that soil test and tell you more about the soil you have.

    1) Soil test for organic
    material. From that soil sample put enough of the rest to make a 4 inch level in a clear 1-quart jar, with a tight fitting
    lid. Fill that jar with water and replace the lid, tightly. Shake the jar
    vigorously and then let it stand for 24 hours. Your soil will settle out
    according to soil particle size and weight. For example, a good loam will have
    about 1-3/4 inch (about 45%) of sand on the bottom. about 1 inch (about 25%) of
    silt next, about 1 inch (25%) of clay above that, and about 1/4 inch (about 5%)
    of organic matter on the top.

    2) Drainage. Dig a hole 1-foot square and 1 foot deep and fill that
    with water. After that water drains away refill the hole with more water and
    time how long it takes that to drain away. Anything less than 2 hours and your
    soil drains’ too quickly and needs more organic matter to slow that drainage
    down. Anything over 6 hours and the soil drains too slowly and needs lots of
    organic matter to speed it up.

    3) Tilth. Take a handful
    of your slightly damp soil and squeeze it tightly. When the pressure is
    released the soil should hold together in that clump, but when poked with a
    finger that clump should fall apart.

    4) Smell. What does your
    soil smell like? A pleasant, rich earthy odor? Putrid, offensive, repugnant
    odor? The more organic matter in your soil the more active the soil bacteria
    will be and the nicer your soil will smell, to a point. Too much organic matter
    can be bad as well.

    5) Life. How many
    earthworms per shovel full were there? 5 or more indicates a pretty healthy soil. Fewer than 5,
    according to the Natural Resources Conservation Service, indicates a soil that
    is not healthy.

  • 9 years ago
    last modified: 9 years ago

    First... 7000 sq. ft. is large. In order to maintain that large a space, strategies are needed. Of course pregnancy was obviously a factor that limited your abilities, and burn out can quickly happen when people become overwhelmed.

    Before you consider not planting anything next year, I would ask... why? Why not just plant a smaller, more manageable space?

    Next... you're in zone 5. As you described, few, if any places in zone 5 are hot enough for effective solarization. I don't think you'll see the results you're hoping for from trying to kill weed seeds with clear plastic.

    Most longtime gardeners find good results from using methods that deal with weeds as a fact of life. I've found good results using permanent 'mounded' beds, but not walled-raised beds. This maximizes the actual growing space. In a traditional row garden, you might measure the growing space by measuring the entire area. This though, includes all the paths. With rows, that might mean half the area (paths) have to be weeded, but are not planted at all. That's a lot of maintenance for unused space.

    Then there's mulch. Whatever garden design method you use, mulch is perhaps the best choice a gardener can make. And depending on what type pf mulch you choose, it can serve multiple purposes.

    A thick, natural mulch will foil weeds, improve the soil structure and tilth by adding organic matter, help to buffer pH, keep the soil cooler in summer - warmer in winter, feed the worms and other soil life - providing them a protected environment, nurture good fungus growth - simultaneously preventing bad fungi from splashing up onto your plants, improve irrigation and moisture retention, and increase fertility. Seriously, in any space, mulching is one of the best things a gardener can do... and in a large home garden, it's almost a necessity.

    There are many mulching options, and many market gardeners do choose plastic as a mulch. But home gardeners often find the best results from natural mulches... hay, straw, shredded leaves, grass clippings, compost, pine needles, wood chips (kept on the surface,) etc... all make excellent mulching materials. Each one (and combinations of some of them) are used slightly differently for best results.

    Hay for example... in general, hay is often dismissed as mulch because of weed seeds. However, if put down in 4" - 8" layers, weeds will not germinate easily, and have to struggle to reach the surface. Any that do make it through are easily pulled by hand. I'm not exaggerating when I say that 98% of weeds will be defeated by a thick layer of such a mulch.

    Wood chips too make a good mulch, and just a few inches work well. I use them on my paths, and very few weeds will germinate in wood chips. If you use wood, just keep in mind that large wood chips (over dime size) - or a lot of any size - should not be tilled into soil. They will temporarily tie up certain nutrients until they decompose. But, on the surface, they do not interfere with nutrients and are very good at restricting weed growth - especially on paths.

    Mixing grass clippings with hay or straw makes for a great mulch, as do shredded leaves applied in winter and kept on the beds until planting time. This will keep your beds nearly weed free.

    And when time to plant gets close, with the exception of wood chips, just turn the mulch under and that feeds the soil! The worms will love you. An added benefit... many/most of these products are free - with the work of gathering them.

    Especially for those areas that aren't doing well, consider investing in a soil test. Yes, home evaluations like mentioned above are good options, but a soil test from a professional lab should not be dismissed.

    Cover crops are good, and you can use it in the areas that did not perform well for a year, but that may not solve the problem. You need to identify the problem with a soil test, then take the appropriate measures. With a space that large, consider fallowing a section with cover crops, and planting a manageable plot. Start smaller, get established, and grow a little each year. Once you find a good maintenance program, and get it established, expanding the garden becomes much easier.

    In my case... once I get a bed dug, amended (adding fertilizer, and organic matter,) planted, mulched during the growing season and covered during the off season, I only have to maintain that bed a few times a year. If I were to till the entire garden, that would be a huge task akin to starting from scratch each year! So, start smaller. Get the bones established. Decide upon a good maintenance schedule - tied in with the seasons. Then expand a little each year. I think you'll find more satisfaction, reduce your work load, and each year your soil will get better and better.

  • 9 years ago

    I have an idea that a biological assay is important. Those struggling plants may have root knot nematodes and you will not know until you pull up some roots. Its a neat idea to stimulate biodiversity until it bites you. And remember, some of these great organic thought leaders are using microscopes and insuring sterilized compost via hot methods, so do not sweat a soil sterilization technique when you come across one you like. You wont be able to keep it sterile, just help the plants get great start toward production. And some fungi, like fusarium, and bacteria, like wilt, need to die a horrible agonizing death anyway.

  • 9 years ago

    rgreen48 - in 2016, we did mulch heavily. Since we had just moved, we had an abundance of cardboard boxes, so I broke them down, removed all the tape, and laid them down in the garden, covering them with wood chips we chipped ourselves (mostly maple). I was hoping to always utilize the "no-till" method in our garden, but with the way it looks now I just don't think that's possible :) At least until we get things under control. This year, we had access to a lot of free hay (my in-laws horse died shortly after they got their hay delivery for the year); they delivered quite a few bales but my husband never had the time to spread them out and they are still sitting next to the garden. We'll add those to the soil either this fall or next spring, since they are breaking down nicely. So a huge part of our weed problem is that we didn't use mulch, at all, this year. And as I said, my husband was just too busy to get out to weed very often and I was more or less out of commission! If I knelt or sat on the ground, I wasn't getting back up! haha

    Our garden was smaller the first year - this year we added a 40'x40' area just for squash and a 25'x25' area just for corn. And the very north row of the garden (about 1200 sq ft) is planted with perennial berries (various raspberries and blackberries). You are right about the remainder of the garden - about half of that space is "paths" between rows or beds of vegetables; my husband didn't waste any of his time weeding these at all this year and they look the worst. The squash patch is not nearly as bad as the rest of the garden, even though it's new - as glib said, the squash shaded everything else from the sun. We do have some amaranth growing amongst the squash but it's not too bad.

    We do plan on planting a few tomatoes and cucumbers next year, maybe a couple squash; I like to can, so it would be nice to still have a couple of our favorite vegetables. The main reason we plan on skipping a garden next year is to try to get the weeds under control. We also had a terrible year this year, weather-wise, and burnout is a factor - it's disappointing to put in a lot of work and then have all your potatoes drown because it rained 25 out of 30 days in June, or have 75% of your tomatoes not ripen because August was incredibly cold, and then to get the first frost on August 25th (2016's first frost was October 14th!). We'd also like to focus on other projects next year and have plenty of free time to have fun with our new baby, who by then will be walking. We live near Lake Superior, so we'd love to be able to take her to the beach or boating if and when we get hot days :)

    Waiting a year would also give us lots of time to chip more wood. My parents cut their own firewood, and so they have no shortage of branches piled up around their property. Last year, we rented a chipper and got about 9.5 cubic yards of mulch in one day. We can rent a chipper this spring and again next fall and have lots of wood chips come spring 2019.

    When we moved here in 2015, I did do several tests on the soil like kimmq suggested. We have cobbly, sandy loam soil that drains well and has loads of earthworms. Organic material, drainage and life all seem good. I have not sent in a sample to be tested for ph or nutrients though. I can do that this fall, soon.

    Our cover crop for this fall is the Fall Mix from Johnny's. We'll use their Spring Mix next spring.

    I know we'll never be rid of weeds, and that's fine... I'd just like to get a better handle on them so it isn't so difficult keeping up with weeding. If were taking a year off anyway (which we probably are!), I figured we might as well spend that time improving the soil and reducing weeds instead of just letting it sit!

  • 9 years ago

    you have to tolerate weeds. They are helping your fertility after all. But you can nearly eliminate them by planting clover in parts of your garden. The price to pay is that part of the garden will then accept only transplants, no direct seeding. And you have to make sure you use very low white clover. I have forage white clover, gets to be one foot tall, and occasionally it overwhelms cabbage transplants.

    another way is to plant your own edible weeds. a carpet of red mustard will not allow anything else to grow ( or very little else) at my place. it matures in May, so you can pull some plants where you will be planting the tomatoes. Turnips behave similarly at my place.

    There are potatoes and garlic under mulch. you mulch heavily, and only garlic and potato shoots will make it past the mulch. weeds have too small seeds to do the same.

    and then there is vining squash. Planted at the right time, watered well, after you mowed the weeds, it will easily overwhelm most weeds. keep trying, you will get somewhere.


  • 9 years ago

    Thanks everyone! So I take it none of you would utilize any sort of weed barrier (plastic or fabric) during our off year?

  • 9 years ago

    no. besides, a cover crop is a fairly natural ecosystem. it should attract seed eaters (beetles, slugs, earthworms) from the surrounding area. surface weed seeds will decrease.

  • 9 years ago
    last modified: 9 years ago

    Do less tilling - all it does is bring weed seeds up where they germinate - and more no-till control measures like herbicides, mulches and cover crops.

    Your plan sounds like way too much work.

    DO NOT start fertilizing and amending until you know the current conditions. You can over-manure into garden failure. Get a good commercial soil test before you do much else.

    I would not skip a year, but I would cut back on the size of the growing
    area to something you can handle with a baby in the house, for the things that grow the best in your area. A small, but better-tended area will give you more yield for the work you do. You were trying to cultivate something about the size of the infield on a baseball field.

    Thickly mulch the rest, or plant a cover crop onto it to keep the weeds down. Even a dead cover crop will suppress weeds by blocking sunlight.

    Pay attention to how much sun things get and need. What you describe for the cucumbers sounds like one end of the row got more sun than the other.


    ADDING: If you have access to wood chips, spread them as you acquire them. Don't stockpile them when they could be out there suppressing some weeds for you.

    Mulching a small area properly - 6-8 inch minimum for good weed suppression - is more effective than spreading a scanty layer over a larger area.

  • 9 years ago

    No, I don't use, nor recommend weed barriers. Some with market gardens use plastic effectively, but for the backyard gardener, they are not often effective. They cost money, need to be pulled up each season, and force an irrigation system to be used because they restrict water from reaching roots. Even when used properly, they breakdown in sunlight and can cause a mess. Natural mulches have all the benefits mentioned above, and for the amounts needed for even a good-sized home garden, are easily obtained for free.


    And. if you ever have the misfortune of getting plants and roots (especially shrubs) growing through those fabric mulches you'll instantly regret ever knowing they exist lol. Ask how I know... :-)

  • 9 years ago

    lazy_gardens: the size of the garden was only an issue this year because I couldn't be out there as much as I had hoped, had thought I could be or as much as I had been the previous year. We had no trouble last year. And as I said, tilling wasn't our first choice.

    We'll get a soil test asap, but we are almost 100% decided that we will not be planting the majority of the garden area next year; instead of just leaving it to the weeds, we will be planting cover crops.

    The only portion of the garden that gets any shade is the berries on the north, and they only get shade very early in the morning. The rest of the garden gets full sun all day long - absolutely no shade. We also water evenly.

    Basically, since we are decided that we will significantly scale back next year, I was just wondering what we could be doing in that time to improve our situation for the year after, and every year after that.

  • 9 years ago

    Has anyone tried using a crimper to create a thick mat out of the cover crop?

  • 9 years ago

    Yes, I had one and it worked more or less with rye. But now i switched to all winter-killed cover crops, of which I have too many, plus vetch which is easily controllable with mats of leaves after it resumes growth in spring. You need a 2X4 piece of wood and a piece of thin 90 degrees angle steel, and a piece of string to hold it as you move down the bed. the length of 2X4 and the length of steel must equal the width of the bed.