weeds in veg garden

[Bainfield]

Hi I live at the bottom of the south island of new Zealand. last year being my second season of planting a veg garden I decided to mix horse manure into the soil. This has grown nothing but weeds for me since. I have this stubborn weed that looks like grass, the roots of it run so deep I wonder how I will ever get on top of it. I have had the top layer taken off by a digger but still the grass pops up and the thick roots run on and on . I am reluctant to use a spray in the veg garden but I'm at the stage I may just have to turn my back on it I would love some help if you can .

[rainbowgardener]

I guess your manure wasn't composted enough. A couple thoughts:

You are coming in to warm season, right? If you don't mind giving up part of a season of gardening, you can solarize the area. Till the soil, and collect and dispose of dead plants and other debris that might harbor pests. Level and smooth the soil surface. Water the soil very well as deeply as you can, to increase its heat conductivity. Lay a clear plastic tarp (like 1 to 4 mil painter’s plastic) on the soil surface. Anchor the edges of the tarp with soil, tightly, all around the border. The closer to the soil surface the plastic is, the better the heating. Remove the tarp after 4 to 6 weeks­. Everything in the top six inches should be pretty cooked, especially if you have hot sunny weather. No more weeds, but also some of the beneficial microbes and insects will be cooked, so you will need to rebuild. But at that point, you don't want to till again and risk bringing more weed seeds up from below the sterilized area, so just take the plastic off and plant.

The other possibility, especially if you are talking about square feet of garden, not acres of garden, is cardboard mulching. Water the garden, cover the whole thing with a good layer of cardboard, being sure to over lap the edges (or you can newspaper, but then it would need to be a bunch of layers). Water the cardboard/ newsprint. Then cover it with 4-6" inches of clean new soil. You can plant seeds in that. If you are doing transplants, you can make some holes in the cardboard to plant in to. Before the end of the season, the weeds will be smothered out and then the paper rots away and you are left with a deep fluffy planting bed. I have turned some patches of lawn in to flower beds this way.

[imafan26]

I have weeds everywhere, you can do what Rainbow said. I have mulched with newsprint and potting soil over that and I did get relatively fewer weeds. Eventually the weeds did break through the newspaper mulch, but I have nut sedge.

I just now take out what I can and just plant. If your crop grows faster than the weeds the weeds will actually slow since they need the light. At the end of the crop cycle I remove as many weeds as I can and plant again. If I am not going to plant for a while, I cover it with black plastic just to block out the light and water. It does not kill the nut sedge but it does slow it down.

The other way to reduce the weeds that may work since you have grassy weeds is to water your weeds, pull them before they go to seed and repeat until you don't see any more come up. The key to making this method work is to till and amend just the first time, after that just pull and water. If you till again you will bring up more seeds to the surface and they will sprout and it will be a much longer process. After you plant, mulch around them to reduce weeds between the plants.

Fresh manures have a lot of weed seeds in them depending on what they eat. That is why it is better to add manures to compost.

[digitS']

This must be a perennial and reproduce from those long roots. Maybe there is seed as well, at some stage of development.

I took over a vegetable garden that had been tended by an aging gardener, then seriously neglected by his son for a season. Quack grass was everywhere!

I decided to use that garden for flowers that first year. I will use herbicides on the paths in the flower garden. Mulching the paths has not helped much with quack grass. The rhizomes have no trouble traveling in one direction or the other in my 2 foot paths and showing up in the beds! Two foot paths, four foot beds - could, at least, limit my hand weeding to two-thirds of the ground. I had the quack grass out of there at the end of the first season and it has grown vegetables ever since, about 12 years.

The rhyzomes travel and they also, persist. I took a black plastic bag of them once and left it closed at the corner of the garden, all summer. Those quack grass rhyzomes were still alive at the end of the season!

Here is wishing you the best of luck!

Steve

[btrowe1]

I do the old hands and knees trick, pull them all, I do a little at a time,try to get into the garden at least once a day. I've been doing it this way for years.

My rows are about 20' long so I only try to do 1 row or 1/2 a row.

It gives me a chance to reflect on what I have growing and helps relieve the stress after a days work.

Good luck with your growing season this year, enjoy.

[jal_ut]

Here we have what most people call Quack Grass. It is a perrenial with rhizome type roots. The roots travel and are quite persistent. However they don't go real deep. 6 inches at most is what I would guess.
Several ways to kill it.
1. Spray with a herbicide. (Works, but I won't use chems)
2. Dig the roots out and remove them to the garbage can. Very effective.
3. Till it deeply once a week for a month. This pretty well gets it.
4. Solarize with plastic as rainbowgardener mentioned.

None of these things can really be done with crops growing. Use the trick btrowe1 mentions if you already have crops growing. Hands and knees.
If you can keep the green off it the roots will eventually starve and die, but it is best to remove them. I don't know exactly what your grass is, but it sounds similar to Quack Grass and the remedies I mention should work.

[jal_ut]

The age old remedy for weeds is hoe, hoe, hoe. ( Be sure to sharpen the cutting edge.)

The roots of crops are quite close to the surface so you can't really till very deep between rows (if you use a tiller to weed) or you will damage the crop roots too.

You can take your hoe and just run it about 1 inch deep and cut off the weeds. Annual weeds are usually killed simply by doing this and it is pretty easy if you do it when the weeds are small. This also gets the green off the perennial grass and if you keep at it the roots soon loose vigor and die.

Wheel hoes are nice if you have a fairly large area. (Do a Google image search for "Wheel Hoe")

Of course even after hoeing the area, you will likely need to get on hands and knees and weed around the plants. You can pull or do like I do and use a butcher knife for close weeding.

[rainbowgardener]

If you really want to get rid of something that spreads by roots/rhizomes, check out the post by Cynthia_h, former mod here, in this thread: https://www.helpfulgardener.com/forum/vi ... hp?t=38084

She built a sifter and basically sifted all her soil through it (not sure to what depth). Sift out all those roots. She said she spent 3 days doing it and then never had her Bermuda grass problem again in the next decade. But I think she was only gardening about 100 sq feet. If you have a small garden like that, this is more or less manageable. If you are talking about 1000's of square feet, probably not.

[Gary350]

Once I put a truck load of cow manure on my garden and it grew a nightmare crop of weeds. It took me 3 years to get rid of all those weeds. Some seeds only grow when they feel the heat from the sun and the soil is moist so I tilled the garden every other day for a month. That made most of the seeds grow and the tiller killed the plants. I had to be very careful to weed the garden and not let any weeds get large enough to make seeds. Don't pull weeds then throw them down in the garden take them to the trash can.

If you heat the manure to about 150 degrees it will kill the seeds. Cover your manure pile with black plastic or keep it in 55 gallon barrels painted black with lids in full sun. You can also mix manure with water in a tank then build a fire under it.

I sometimes keep my manure in a tank of water for 6 months before I use it. The water is great fertilizer.

Rabbit manure is very good and it has no seeds.