Hi Louisa
(For everyone else reading this: I taught a local 3 hour class on permaculture to the master gardeners earlier this week and Isabella and Louisa attended it.)
IsabellaC said:1. are you going to have more seminar about permaculture in the area?
Not at this time. Historically I give the same class each year to the master gardeners. In the past I have lectured around the state but since taking over NGA I have had to say "no" to most invitations to speak.
IsabellaC said:2. you mentioned that weeds are not all bad. In our garden, though, they seem to suffocate everything else I plant, is mulching the answer? and if I need to leave some weeds growing, do I let them grow at the edge of the garden?
Mulch is definitely the answer. I wouldn't tolerate weeds that suffocate my plants. Leaving a chickweed here and there is one thing, but letting weeds take over your garden is a different thing.
Clearing out a garden and applying mulch is the best thing you can do to prevent your weeds.
IsabellaC said:3. sheet mulch: did I understand correctly, that you do multiple layers of mulching? pine needle or hay and cardboard, and compost and then again, cardboard, pineneedle...etc?
Start with the cardboard straight on the grass. That's the only cardboard you'll use. Then add on the layers of compost, manure, soil, pine needles, leaves, etc. Try to use thin layers.
IsabellaC said:4. when I need to till my garden, can I till it with that mulch in it?
You sure can. That'll just mix the mulch into the soil where it'll break down faster and improve the soil with organic matter.
(Having said that... a good sheet mulched bed will never need to be tilled.)
IsabellaC said:5. you spoke against Grazon, is there other sprays that don't "stay" in the ground like that one?
None that I'm aware of. As far as I know all those herbicides tend to stick around and cause you problems. The rule of thumb is don't use hay in your garden if it's been sprayed by any herbicide.
IsabellaC said:6. Does it make a difference if you use a pre-emergent spray? I am not sure, but I think Grazon is not pre-emergent...
Grazon is not a pre-emergent. It kills actively growing plants.
I do use a pre-emergent every spring and fall and it has very good results. If you want to hear more about that, check out our podcast #106:
https://garden.org/ideas/view/...
and the thread about it:
The thread "Herbicide Dave Mentioned in Podcast 106?" in
ATP Podcast #106: Pruning Clematis, Some Thoughts on Herbicides, and Other Stuff