Raised bed taken over by invasive roots.

I am a new gardener starting just this year and I think I'm paying a big price for buying poor soil for my raised beds. I apologize since this might be a long read and sorry for the impending noobness.

When I started making my raised bed for the first time, I didn't know what soil I should use, I bought a Home Depot in house brand called "Vigoro" Organic. As I learn more about soil in the coming weeks, I quickly realize they are extremely poor quality, they have very low pH (4), very heavy, and terrible at keeping water. The plants have a hard problem healthy roots since they are so heavy. You could water the soil as much as you want and they would still be dry. Even after adding expensive amendment like compost, rockdust, biochar, compost tea, my plants weren't doing well.

Mean while on the side I bought the Lambert OMRI certified potting soil which is also sold at Home Depot, and used them for container planting and in a separate bed for strawberries, all the plants are doing well with these. The soil was so soft and kept water very well. With them I could nurse leave-less dried up stick Goji berries plants to a state of growing prolific green leaves. I decided to use the Lambert soil in all raised beds, so what I did was chug away most of the Vigoro soil to the side, only leaving about 6 inches in the bottom of the bed as fillers, and the Lambert soil above.

What I didn't pay attention to was that the Vigoro soil seems to come with some type of invasive roots, they seem to be thicker in the bottom layer where the Vigoro soil was, now they are growing so fast they take over every part of the raise beds. I don't have enough experience to know what they are. They are very soft and thin, but very spongy if squeezed, but they are very prolific and found everywhere under the surface. They are very fragile and easy to break off, so they seem harmless, however since they're everywhere it is impossible to rid of them and I fear they might just get thicker over time and have a stranglehold on all the soil space. They are not part of any plants that I introduced to the soil.

I asked elsewhere on the internet and they told me it was wrong to put cardboard/landscape fabric in the bottom because the plant roots would have no where to go, and that the invasive roots could have came from outside since the soil couldn't just sprout roots. I moved in this house not too long ago, below my raised bed at lots of trash and cement, so I wanted to take caution and used landscape fabric and cardboard as a shield, especially from weeds. I do not believe the roots came from outside, but already existing, otherwise it could not have taken over all of the beds in only 3-4 months since almost every inched of the soil have these roots. But I could be wrong, so I look for input from more experienced gardeners. I don't believe the roots came from the Lambert soil since strawberries bed that only used Lambert soil have no traces of these invasive roots.

Right now I am in distress and enraged about this since I spent so much money on the soils itself and the amendments. Starting from scratch would very too costly, so I'm just gritting my teeth and grow my less valued vegetables there for now.

I guess it is less important to know exactly what the roots are, but to hear from more experienced gardener who had with this issue before and what action did you take. Are there tips to suppress invasive roots growth? It is okay for my vegetables to coexist with these invasive roots and still be healthy and thriving, or would there be negative impacts on their rhizome growth while the roots battling each other for room to grow? I have no intention of using any unnatural chemicals on my soil.

Whether if I am incorrectly attributing the roots problem to the Vigoro soil, it had been a terrible mistake for me as a first time gardener, and I initially bought them because I wanted to avoid using Miracle Gro due to their poor reputation, but looks like these are just as bad.

Thanks for reading. Any input would be helpful.

This message was edited Dec 14, 2014 3:42 PM

I know. Sometimes it's just trial and error. I use good bagged compost and avoid buying soil altogether. I imagine the roots did probably grow in from elsewhere. What is growing nearby?

When I moved into this house the entire backyard had a lot of weeds. I am now convinced dayflower is my worse enemy of all time. There are also spurge, crab grass, oxalis, nutsedge, quickweed. There are also lots of little woods fragments and cements.

We pulled out almost all weeds around the growing area already so there is no problem growing from the ground, although the weed roots are still there so it's an ongoing maintenance, the remaining growing weeds mainly stay near the fences. Right now I am planting crimson clover to hopefully suppress the other weeds, I wonder if this is a good or bad idea for a backyard. I wouldn't mind growing a cover crop for the whole garden if they don't get out of control.

Before I put on my raised beds, I pulled most of the weeds, then put some old carpets over the area for about a month. When I installed the beds, I had two layers of landscape fabric and one layer of cardboard box. I guess it is perfectly possible outside roots could invade the raised bed from the edges.

Right now I seem to enjoy planting from containers most since I have control over more factors.

This message was edited Dec 14, 2014 3:42 PM

It could be a number of things, when we clear an area that has been neglected for a few years and has become overgrown with several different types of weeds, it's very difficult to get ALL the roots out as we dig,some weeds /grasses sand perennial type of flowering weeds get their roots broken as we dig, any tiny little parts of the root system left in the soil will just regrow, thats what nature intends them to do for reproduction of the plants, I always find for the first few years AFTER I think I've cleared an area of ground, I'm still weeding the soil as the little shoots come through, unfortunately, that's nature, it's the fittest of the plant world that can survive and the weeds are the fittest normally. IF you plant seeds in this area, you need to make sure they are in rows / lines, or marked by caned / sticks / labels etc or when you weed, you could pull out your little seedlings.
As time goes on, you will soon recognise the diffence between a weed seedling and your germinating seedlings BIT you need to allow a few of the little leaves to form before you pull or again, you could be leaving the weed seedlings and tossing your planted seeds out.

Beds take a while, several seasons to settle down by adding humus, horse manure or home made compost, these are best additiveds for soil conditioners, it allows air into the soil, helps hold onto moisture, feeds the plants and helps keep the soil sweat and crumbly for growing either veg, flowers or fruit trees and shrubs, every year do a soil test (cheep kit from garden store) it will tell you IF you need to add more lime, Horse manure etc depending on what your planning to grow.

Go along to your local library or book store to look for beeks on beginners gardening, dont buy eny expensive books, just look for maybe a soft covered one that is plane speek English as some are way too much in depth for a novice gardener and you get put off by all the scientific mumbo jumbo so called experts like to impress with, they are normally expesive rubbish BUT nice pictures, my oppinion naturally.
Try enjoy your new found gardening hobby, remember it's supposed to be enjoyable NOT something your life is depending on and take your time, a garden was never built or planted in a day.
Get to know your soil, what grows in your area and when best to sow the plants then you will love the results.
Take good care and relax.
Best regards.
WeeNel.

I have to hack out tree roots that invite themselves to my pampered raised beds. There is a look alike dayflower, asian something, that rides in from flower pots and tends to take things over. Since I live where everything is invasive, its just choices at what gets cleaned when. Goodluck with your roots.

Might just rototill really well, chop them all up. Then pull whatever still grows, knowing that it does not have an extensive root system any more.

This happened to me from Raspberries. My yard was all trees but after cutting them down some dormant roots must have come to life because I have a huge patch! They keep trying to invade and re grow in my area designated as a raised veggie garden.

Max, I sympathize with your situation. When I was a new gardener I bought bagged soil for outdoors, but now I mostly use my own homemade compost and mulch by the square yard from a loam company. You could probably have bought garden soil for 1/10th the cost from a loam company. I suggest researching local companies using words like loam, mulch, etc.

Regarding the strange roots, plants often thrive surrounded by other plants so I don’t think it’s a big deal. For example, many gardeners pack different vegetables in a garden planted like sardines side by side and all the plants are healthy and green. So I think your plants will probably grow well in the root-filled soil. By removing the weeds that grow above ground and tending your plants over time your plants can grow stronger while the weeds become weaker.

Fertile soil attracts weeds, so weeds are actually a sign of good soil. My South Garden was chock full of weeds and pachysandra and after two years of trying to remove them with various methods like mulch and pinning fabric over the ground, I finally gave up and just allowed my plants to overpower the weeds. I clipped the weeds above ground every month or so and my garden is covered with healthy plants and the weeds are almost gone. I found that broad-leafed plants that cast a dark shadow underneath like hostas hide and destroy weeds trying to grow under them.

However, I plant container pots in the ground. I’ve never planted seeds in the South Garden. I also suggest planting plants that are suitable for your seaside zone 10b climate with 58” of annual rainfall:

http://www.plantmaps.com/33064

Nancy G.

max,
I am sorry you are having such a bad experience as a first time gardener. That is discouraging.

I don't have raised beds but when I broke ground for each of my flower beds, I had to fight some kind of weedy grass. The roots looks like what is in your photo. It had an extensive root system that travels underground and sends up grass blades every 6".

I first killed anything green that grew with Round Up. Then I cover the soil with black plastic extending and held over the edges of the border and left it over the summer to allow summer heat to fry anything still alive.

The following May (2014) I removed the plastic. Everything at soil line was dead. I handug and turned the soil over. That is when I found small, live grass roots. I'm glad that I didn't till or I would have had chopped up roots with more work. Even tiny roots would sprout.

As I dug and re-dugged down to 12", I removed every tiny piece of root I could find. It was time consuming but had to be done. Before leveling, I added buckets of rotten horse manure and turned it over. My DD and DSIL have 6 horses so there is a never-ending supply.

I allowed the soil to lay a bit before planting to see if any weeds grew. Finally, June 2014 I planted my 117 daylily seedlings.

Photo taken September 2014, still weed-free.

My experience is that most of the bagged 'soils' should be considered soil amendments, to be mixed in with the soil in your backyard, rather than 'soil' to be used as is.

I don't think the cardboard and two layers of landscape fabric was a good idea. Landscape fabric is designed to allow water to flow through. Cardboard doesn't do that. Are you sure the 'invasive roots' aren't fungus mycelium growing in overly damp soil (which would be wettest just above the cardboard)?

Roots have to be connected to a plant, they don't just grow by themselves. If you don't have weeds, I would focus on the plants you are trying to grow, and forget about the 'invasive roots'. Plants need water, but not all the time or their roots will rot. They need sun, but some plants need more than others. They 'need' fertilizer, but not too much or they'll burn. They sometimes need someone to get rid of pests (chemicals are not necessarily the best way to get rid of pests, and the wrong chemical will do no good at all). Most importantly, plants need a little time to develop a healthy root system.

Gardens take time. If something works, keep doing it. If it doesn't work, do something different next time. Most importantly, enjoy what you are doing and don't let setbacks bother you.

As I sit and look at my snow covered beds I envy your weather. I put in raised beds a year ago, first planted this last spring. It was a little daunting to see the price I had to pay to put dirt in them. I compost all year long so I was not used to paying for dirt! I contacted a landscaping company and bought yards of top soil. The first batch I was very unhappy with, it had a lot of clay. The second was much better. I also amended the soil with my compost.

Now, we'll see how it works this spring, but I put the beds right over the grass (which I tilled first) and had good luck through the season. There were some weeds (the birds are always happy to help spread them), but nothing much to handle. Can't wait until this spring. I'm hoping manure and compost will "refill" them as they've settled quite a bit.

The weeds in your picture and description look like crab grass to me. That's very hard to get rid of. Each piece you miss will resprout. In time you'll get the most of them.

Thanks for all your inputs. I cleared out one of the raised bed to make ready for new crops. I looked at the base of the bed around its edges and clearly it must be roots from surrounding tree or weeds that grew into the bed, the roots grew right through the landscape fabric, they invaded the soil so fast. I'm not so alarmed about it anymore, despite the roots there aren't any weeds growing. With that said, I still hold onto the opinion that the Home Depot in house soil brand is terrible.

I manually tilled the soil and break up as much roots as I can, I will have to do this after every grow season, I don't mind, I just don't like hurting earthworms in it. I made about 20lbs of compost over the winter and added some of it to the bed. I also feed my soil with compost tea weekly. Now I'm just waiting for some tomato seedlings to be large enough to transplant. Looking forward to a great grow season.

This message was edited Feb 17, 2015 12:52 AM

It sounds like you are well on your way to a great growing season. Congrats.

If there are roots invading from outside the bed then dig down next to the boxes and cut these roots.

You can bait the earthworms over to one side of the bed with fresh food (try all sorts of kitchen scraps, see what they like best) then rototill the rest of the bed. Then bait them over to the other side to till that last strip.

Looks like he has done that.

A friend told me if I plant my squash and cucumber's close together they will cross breed and ruined the quality of the fruit is this true.

Squash and cucumbers are not related and can't cross-pollinate.

Now - just don't combine men's and women's underwear in the same load of wash...

Hmmm ... that might require and explanation.

I think it's called spontaneous generation...

If it's anything like my laundry, you just never know what might come out of the wash.

This message was edited Feb 22, 2015 8:31 AM

So, THAT'S where snow shovel's gotten to...

lol.