Putting an existing "natural area" into production

[TriangleGuy]

About 50% of our lot was thick with mostly pine trees under which was left as a natural area. We just had all the pines removed leaving only a small amount of hardwoods. Now we are left with some large open natural areas full of pine needles, leaves and big mounds of pine mulch from the stump grinding.

We plan to do a lot of landscaping and put in a garden now that we get enough sunlight to grow more than just mushrooms and moss. But I'm wondering what the best first step is to convert the natural areas to productive growing soil. My wife thinks we should just spread out the mounds of pine mulch and mix it with the natural debris. But I'm worried that all the pine needles will leave a soil that is much too acidic. I'm thinking we should rake up all the pine needles first.

I would appreciate any advice or pointers to information about what to do in a situation like this.

[simy1]

A couple of things. First, acidification is temporary, disappearing as the mulch turns into soil. Second, mixed green/brown debris (fresh needles with wood chips) are less acidic than pine needles by themselves. Third, wood chips alone are themselves acidic but last muchlonger than needles. I would do as your wife says. It is never a good idea to decrease the organic content of the soil. If you have access to wood ash (if you know someone with a wood stove), that is a cheap way to increase pH instantly (it also has K, some P and most micronutrients). This said, most shrubs and trees will like just a thick layer of the mulch you have now. Wood ash will help in areas that you plan to turn into lawn, for a few selected flowers, and for about half the vegetables you may think of.

For example, my front flower bed received one foot of pine wood chips over the first three years, and now for 8 years has received only the leaves that fall on it in autumn. I add wood ash in the three iris patches but otherwise never do anything to it. My kiwis, grapes, japanese maple and chestnuts get a few inches of wood chips most years. If you can not get wood ash (which incidentally should be applied during the dormant season, because it can kill plants in large amounts) get some lime.

With the pine needles in there, which are not only acidic but prevent germination, you might not be able to seed the lawn until september, when most needles will have decayed. Weed seeds will not germinate either. But september is the proper time anyway, since spring seeding is never as good as fall seeding, at least here.

[Karen Fletcher]

Pine needles will have a minimal effect on soil pH.

Raw sawdust and wood chips will take time (and nitrogen) to decompose. If you mix them up with soil and leave and leave them for a year, all will be well. If you have raw wood chips around newly-planted plants, they will hog the nitrogen. (Various state highway departments have found out the hard way that mulching with fresh wood mulch can kill great swaths of plantings.)

Don't mulch too heavily in the root zones of the remaining deciduous trees. Feeder roots need oxygen and too heavy a mulch layer (4" and up) can choke them. It depends on the type and age of the tree, but in general feeder roots extend well beyond the tree's dripline.

Find out more about your soil:

- If you are on a natural forest soil, it is likely to be a fairly poor soil. Anything you can do to increase the organic matter content is a Good Thing. The lighter the soil color, the less organic matter it contains.

- Dig in several places. No earthworms? Soil is poor in organic matter and/or compacted. Sandy soils are also not so appealing to earthworms.

- Do a soil test (multiple locations) or have one done. Soil pH can be a real bear to modify, so you may just want to go with plants that naturally prefer what you already have.

- If you have a local source of composted manure or landscape recycling compost, invest up front and add as much of it as you can afford. You'll never be sorry.

Cheers!

-- Karen

The Garden Gate

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[CD]

Thanks for the help everyone. Happy gardening!