Weed Seeds in my Lasagna Layers - No Till Questions

[rjake100]

I am preparing a couple of beds. The first bed wont be planted until next spring, and I want to start some lasagna layers now. I would prefer to mulch my grass clippings back in to the lawn. As such I dont have a good source for the nitrogen layers in my lasagna. There are a couple of empty lots near my house. These lots are not mowed and are covered in weeds. I am certain these weeds are loaded with seed.

Question 1).

How bad would it be if I mowed that lot and used the clippings in my nitrogen layers? Could I mitigate the risk of emerging weeds by using cardboard as the top most layer?


I have another bed I am using for my fall tomato crop. I dont want to try a bunch of layers now since I am planting it this weekend. For that bed I am going to top of the bed with compost from the dump and some bagged soil conditioner.

Question 2).

If that soil conditioner hasn't broken down by next Spring is there any problem with topping it off with more compost? I am worried that burying the soil conditioner (looks like fine ground pine bark) with another layer of compost will be less than ideal.

Thanks for taking a look.

[shatbox]

My first lasagna plot was formed from weeds and grass from the neighbor but it may have introduced diseases and in the end ir was more trouble than it's worth. In the end I threw it all out and started over with straw and used bloodmeal for nitrogen.

[Redbaron]

Originally Posted by rjake100

I am preparing a couple of beds. The first bed wont be planted until next spring, and I want to start some lasagna layers now. I would prefer to mulch my grass clippings back in to the lawn. As such I dont have a good source for the nitrogen layers in my lasagna. There are a couple of empty lots near my house. These lots are not mowed and are covered in weeds. I am certain these weeds are loaded with seed.

Question 1).

How bad would it be if I mowed that lot and used the clippings in my nitrogen layers? Could I mitigate the risk of emerging weeds by using cardboard as the top most layer?

Don't use cardboard as a top layer. You need the air flow. Otherwise you run the potential risk of making the whole thing an anaerobic disaster.

The only weeds so far to scare me is Johnsongrass. I can deal with it, but it must be dealt with. Not a problem that corrects itself like most things lasagna. I do have a suggestion though, even with Johnsongrass. Mow the empty lots with a mulching mower. Then in a week or two when it needs mowed again, take those clippings instead. Far less likely to introduce problem weeds.

Originally Posted by rjake100

I have another bed I am using for my fall tomato crop. I dont want to try a bunch of layers now since I am planting it this weekend. For that bed I am going to top of the bed with compost from the dump and some bagged soil conditioner.

Question 2).

If that soil conditioner hasn't broken down by next Spring is there any problem with topping it off with more compost? I am worried that burying the soil conditioner (looks like fine ground pine bark) with another layer of compost will be less than ideal.

Thanks for taking a look.

Best way to handle that is start a cool season cover crop right at the end of the tomato season. Winter rye and winter peas work great for this. Then in spring mow it down and bag it, add a weed barrier, use the biomass as mulch over the compost. This way you are growing your own mulch and soil conditioners instead of needing to import products from the outside.

[rjake100]

Thanks Redbaron. I am clear on what I should do in regards to question number 1.

I have a follow up on question 2 and the bed I am planting with tomatoes this weekend. I like the idea of using cover crops as a mulch during the winter months. That makes sense. I am wondering what I should do on this new tomato bed this summer and fall while my plants are in. I need something as a top layer, and I am concerned that a soil conditioning mulch wont break down enough before spring. I dont want to disrupt future layering.

[Redbaron]

Originally Posted by rjake100

I have a follow up on question 2 and the bed I am planting with tomatoes this weekend. I like the idea of using cover crops as a mulch during the winter months. That makes sense. I am wondering what I should do on this new tomato bed this summer and fall while my plants are in. I need something as a top layer, and I am concerned that a soil conditioning mulch wont break down enough before spring. I dont want to disrupt future layering.

If it is moist and has enough nitrogen and air it will rot. I don't see how you could stop it from rotting actually.

However, if for some reason you need more microbes to make it rot even faster, try something like this: Soil probiotic

I seriously doubt you'll need it. You have to try real hard to sterilize soil so much that it stops decaying mulch when moisture air and nitrogen are present. Products like the above show most their benefit when bioremediating VERY intensively high chemical use commercial ag soils. But I suppose I shouldn't assume. If you think you need it, go for it. Otherwise just standard products like a little tomato tone or microgrow applied in the planting holes should be enough....and in very good soils I doubt even that is needed. For most people properly made compost or composted manure is enough to jump start the system. Keep in mind, the idea behind lasagna beds is to have biology like microbes and worms mix the soil layers for you. There is no benefit to somehow preserving the layers intact. If that happens, you did it wrong.

[Lycopersica]

A good layer of biodegradable mulch on top should keep the weeds at bay. A few might poke through but they won't cause trouble if you just pull them out.