pine needles
Does anyone know if it is ok to use pine needles in a vegetable garden to keep down weeds?
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opabinia51
- Super Green Thumb
- Posts: 4659
- Joined: Thu Oct 21, 2004 5:58 pm
- Location: Victoria, BC
Yes it is fine, there is a misnomer out there that Pine needles are acidic but, studies have shown that they are not. They are however, quite recalcitrant which means that they are slow to break down.
This is due to the high concentration of lignin and other compounds in their cell walls.
Anyway, needless would work but, what works better is to lay down shredded leaves as a mulch in the fall and then in the spring lay down more with cover crops (multi species cover crops) to outcompete any weeds that may pop up.
The leaves are somewhat recalcitrant with a C:N (carbon to nitrogen) at about 300:1 and will slowly breakdown, adding both macro and micronutrients to the soil.
Cover crops will help to keep the soil alive with all the microbes, macrobes, invertebrates and vertebrates that it needs to be healthy (and for your plants to be healthy). And when you mow them or if there is a little drought, the roots and foliage will slough off (or (the foliage will) be cut off when you mow them) adding nutrients to the soil which will be broken down by the soil fauna. Anyway, this will assist in making your plants much more healthy (If needles is all you have you can do the same thing with them but, it will take longer for them to break down.)
Watch out for Oak Leaves as they contain an allelopathic chemical known as Coumarin that retards the growth of grasses (if growing corn or any other grasses). Walnut leaves contain Juglone which retards most plants except for a few like tomatoes, I think that Elaegnus Multiflora (Goumi) will grow in the presence of Juglone.
This is due to the high concentration of lignin and other compounds in their cell walls.
Anyway, needless would work but, what works better is to lay down shredded leaves as a mulch in the fall and then in the spring lay down more with cover crops (multi species cover crops) to outcompete any weeds that may pop up.
The leaves are somewhat recalcitrant with a C:N (carbon to nitrogen) at about 300:1 and will slowly breakdown, adding both macro and micronutrients to the soil.
Cover crops will help to keep the soil alive with all the microbes, macrobes, invertebrates and vertebrates that it needs to be healthy (and for your plants to be healthy). And when you mow them or if there is a little drought, the roots and foliage will slough off (or (the foliage will) be cut off when you mow them) adding nutrients to the soil which will be broken down by the soil fauna. Anyway, this will assist in making your plants much more healthy (If needles is all you have you can do the same thing with them but, it will take longer for them to break down.)
Watch out for Oak Leaves as they contain an allelopathic chemical known as Coumarin that retards the growth of grasses (if growing corn or any other grasses). Walnut leaves contain Juglone which retards most plants except for a few like tomatoes, I think that Elaegnus Multiflora (Goumi) will grow in the presence of Juglone.