Lawn Invasion in Raised Beds

My 2 beds are 3' x 4' and are in the third season.  Now things are failing/dying right and left and I have tried everything I can think of to nurture and save my plants. I found a clue at the edges of the boxes which is the invasive growth of a very determined grass - it's my lawn but I don't know what kind it is - does it matter anyway?

When I made the beds 3 years ago I put down weed barrier but now I believe it has failed/disintegrated so I dug down a bit and pulled up a trowel full of dirt.  It was very compacted and filled with long strings of tiny white roots going everywhere.  I dug in a square that is not planted with vegetables so I guess I have to accept that the grass has taken over my beds, right? I do see it popping up as a new plant in about a dozen spots in each bed.  

Tomatillos were doing well but now I believe they have been overtaken with the grass roots.  Persian cucumbers and Chinese yard long beans seem OK - for now I guess - just OK, not great.  Yellow squash and zucchini produce no fruit and blossoms just fade and fall off.  

I planted a few things in containers a few weeks ago to see how they fared outside of the beds.  They are amazing and have grown more in a short time than the things in the beds.  

So am I finished?

I know what I have to do for the future but is there anything I can do to save anything this season?  
I have searched but see no other references to this dilemma - can anyone help me?
Just devastated...

I have issues with grass invading my beds as well. That's one reason I TRY to sift the box before planting. But those grasses MAY have come in with the wind.

Do you have any type of cover over the beds?

So, I'd say sift well and cover once you pull stuff out. Then cover. Maybe with black plastic? That should kill anything in there & protect from more coming in.

You might try a liquid fertilizer. The grass is probably stronger and may be using up all the nutrients-just a thought.
Jo Ann

elevating my beds has solved many of my problems.

Marasella, Elevating the beds above the ground prevents invasion from the bottom. Jimmy posted a good photo showing air space under his beds. You don't have to do it all fancy like he did. You can affix a plywood bottom with holes to each bed and set on 2" x 4" boards set on the ground every 2 feet. Weed fabric and a thick layer of wood chips in the isles and around the perimeter of the garden will also help keep the grass from growing there.

I think your raised beds are brilliant, Jimmy.  I might have gone with that if I known or thought or read of it before I made my beds.  Not sure I can manage it now but if I can I might just put it on cinder blocks.  What is your bottom made of - really just plywood to hold all that dirt?  Not sure exactly what Sanderson means by  -

"You don't have to do it all fancy like he did. You can affix a plywood bottom with holes to each bed and set on 2" x 4" boards set on the ground every 2 feet."

Anyway, my question was about saving this season's crops but after I posted the last I dug a little deeper in my 12" beds.  Once the trowel went to 4 inches it was impossible to get deeper.  The roots at that depth are so thick, entangled and compacted that it's impossible for seeds or transplants to spread their roots.  So, of course, the grass is taking all the space and all the water and all the nutrients and anything I add will just benefit the grass. Now I know I cannot save anything and I will just try to enjoy the meager harvest.

...and then a light went on when I realized how well the transplants I potted for comparison to the mangled beds were doing.  I quickly gathered all my large pots, my own compost, purchased compost and good dirt, and any and all established nursery transplants that looked willing - summer squashes, eggplant, cucumbers, Roma tomatoes, Vidalia onions, herbs, etc., and quickly potted them all up.  I am in long season Southern Cal. so they are thriving and have a great chance of good production before really cold weather sets in.  Now I have something to look forward to and hopefully to lift my depression!

Marasella, Read this thread, it's only 2 pages long. There are several ways to elevate the beds off the ground once you have installed a plywood bottom with holes. Holes should be 1/4" with one in the center of each square foot, and one in each of the 4 corners. You can use legs, cinder blocks, bricks, pavers, treated wood, etc. to get that air gap underneath the plywood. https://squarefoot.forumotion.com/t17608-roots-roots-roots-really-need-some-help-on-this-one?highlight=roots

I would not use plywood for holding in a beds contents. Plywood in a short time, even treated plywood will separate it's layers due to constant moisture.
I used 5/4 deck plank that's treated, a space between planks and 3/8th holes spaced around the square.
Having strong enough support underneath is important as there's a lot of weight being held up..The additional cost is minimal at the very least.
All of my young life I have skimped and saved in order to do things..
computers.....cars.....buildings.....remodeling.....etc. Those years I was able to most afford the better items than I had.
These mature years when I can least afford everything I find myself going for the better items...why ? because they last, and are better. Take for example the plywood vs deck plank..deck plank is a wee bit more expensive, maybe the price of an ice cream sunday...I did the deck plank and had the sunday anyway.

MrBooker wrote:Marasella. 
Did you use and Miracle gro when you made your SFG?  We planted some Hostas in a raised bed and we used Miracle Gro planting mix. It wasn't long before we had trouble with the same root problem.


We were told they were hair roots or spider roots. We dug all of the plants up and replanted in MM and looks like their doing a lot better.
We blame it on the Miracle Gro.   Just a thought.

Miracle Gro will destroy all microbes in the soil food web..This is what your compost attempts to put together.
Using it, along with any commercial fertilizers and you will always need to use them.
 I am starting to add blood, and bone meal to m plants now, I believe their lacking something in the line of nutrients..

Jimmy Cee - did you put landscape fabric on top of the deck boards or any hardware cloth.  I don't see the purpose in the hardware cloth but maybe the landscape fabric to keep the MM in the bed.

Also, it looks like you nailed the deck boards to the bottom structure and then set the actual growing bed on top without a bottom attached to the top growing bed..  Is that true.

Note of interest. Jimmy and I have different likes for the bottoms, Jimmy likes treated 5/4 deck planks and I like 3/4" plywood. I just went out side to look underneath the beds at the formaldehyde-free plywood bottoms with a large mirror. Still solid, 97% of their areas are dry, with no sagging between the 2' spans. Of course, we live in different environments. Maybe the dry, mild climate of California allows the plywood to keep dry, especially in the summer, therefore, to last longer. Maybe deck planks are better in the wetter climates.

yolos wrote:Jimmy Cee - did you put landscape fabric on top of the deck boards or any hardware cloth.  I don't see the purpose in the hardware cloth but maybe the landscape fabric to keep the MM in the bed.

Also, it looks like you nailed the deck boards to the bottom structure and then set the actual growing bed on top without a bottom attached to the top growing bed..  Is that true.

Yes for the landscape cloth, a high quality 2 layers criss crossed. Then flooded bed to be sure drainage was good.

Deck down, then side posts screwed to corner posts.on top of deck.