Gardeners agree that mulching bare ground and around plants is THE single most important thing they can do to create low-maintenance, healthy gardens. (Gardening guru Paul James calls it “the greatest labor-saving gardening product ever invented.”) It’s right up there with choosing the right plants and watering adequately.  Yep, I’d say those are the big three.
TYPESÂ OF MULCH
If your soil is already good, then you might choose pine needles, shredded wood chips and bark, which are all long-lasting and look fancy. But if your soil isn’t great, mulching is far and away the easiest way to improve it, as long as you use nutrient-rich, fast-decomposing mulches like compost and leafmold.
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Another factor to consider is that some mulches use up soil nitrogen in the process of decomposing themselves, the worst offender being wood chips, which should only be used on paths or play areas, never around plants. There’s disagreement about whether dry leaves, sawdust, and pine needles rob soil of nitrogen, however. One horticulturist I consulted recently opined that if used in layers of 2 inches or less, there’s no problem. For an attractive but still natural-looking mulch, bark chips are probably the best choice, but they’re not cheap.
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My favorite mulch and the one I use about 10 cubic yards of every year is leafmold, which I use to cover all the bare soil on my property in April. Then for a fancier look in my seating area I use bark mini-nuggets.
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**Look for the asterisks – they’re the best mulches.***
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**Compost is plant or animal waste that’s completely decomposed and now looks something like coffee grounds – black gold. It’s expensive but wow, what a great source of nutrients it is, and a boon to soil structure. (It’s also better than anything as a soil amendment – meaning something that’s mixed into the soil itself, maybe half and half, often at planting time, though I use free leafmold for this purpose.)
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Here’s the other negative about compost: weeds just love it. So while it doesn’t come with weed seeds in it, wind-blown seeds land on it and thrive. So compost used as a mulch isn’t as good at weed prevention as the other types.
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Oh, and some gardeners, including myself, don’t like the look of it on top of the soil because it looks like, well, soil. To me a garden that’s “mulched” with compost doesn’t look mulched unless it has some other mulch on top of it, an organic one that hasn’t fully decomposed.
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**Leafmold is simply chopped and aged leaves. Though it’s rarely sold, it’s pretty easy to make and many local governments provide it for free or very cheaply, so check into it. (Or inquire about starting a leafmold mulch program in your area. Even better are the governments that provide leafmold AND compost AND chopped wood.)
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But back to leafmold, it’s superb all-around – nutrient-rich and excellent as mulch or a soil amendment.
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Leaves are not attractive unless shredded first, which is highly recommended to speed their decomposition and prevent matting and subsequent smothering of your plants. This can be accomplished simply enough using a rotary mower with a grasscatcher can be used.
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Pine needles are often available cheaply and they’re slow to decompose, but they may deplete the soil nitrogen. Additionally, they make the soil more acidic, which is fine for some plants but not most.
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Sawdust is the worst offender when it comes to drawing nitrogen from soil in the decomposition process.
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Cypress mulch is to be avoided because cypress trees are needed where they are – fragile wetlands.
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Hay may be cheap but it’s not considered attractive, so it’s used mostly in vegetable gardens.  It also contains weed seeds.
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Straw is closer to being weed-free but it’s still unattractive, unless chopped (and even then, not so much).  It can also rob nitrogen from the soil. It’s used mostly in vegetable gardens.
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**Bark is moderately expensive to expensive, slow to break down and good-looking. Redwood is especially attractive but more expensive and not great at retaining water. Cedar bark can crust, preventing water penetration. So pine or “hardwood” bark is best (see next bullet point). Fresh bark can be toxic to young plants, so age first, or buy bark that shows some of the discoloration of age. And speaking of store-bought, some brands are mixed with large amounts of shredded wood, which bleaches white, so look for an even dark color. It comes in nuggets and mini-nuggets, or shredded, with the shredded version preferred by many gardeners who’ve seen their nuggets wash away during hard rains.
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**Pine Fines are fine-textured pieces of pine bark, aged and screened. Looks great as a mulch but also outstanding mixed into the soil as an amendment.
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Wood chips or shavings are attractive, break down very slowly, and are moderately priced and sometimes free from municipalities or tree companies. Still, because of their nitrogen-depleting properties, I recommend them only on paths or play areas. (They won’t do much for your earthworm and soil microbe populations, either.)
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Dyed mulches are usually made from waste wood like pallets and the dyes are reported to be nontoxic, but waste woods often contain arsenic and other toxics that leach into the soil. But then they’re so ugly you wouldn’t want them anyway.
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Rocks and gravel look good in rock gardens but don’t improve the soil or prevent weeds very well. And after they’re applied in planting beds it’s difficult for the gardener to get to the soil beneath. Plus, stone gets dirty and needs to have leaves and debris blown off and be “freshened” with new stones.
Other nonorganic mulches (rubber, anyone?) may work well under swing sets.
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HOW MUCH MULCH DO YOU NEED?
It’s easy. To determine how many 2-cubic-foot-bags you need to provide 2 inches coverage, divide the square foot area of the garden by 12. For 3-cubic-foot bags, divide by 18.
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SOURCES
DC’s Department of Public Works collects garden waste like Christmas trees and leaves and mixing it all up into what they call a “rough mulch” that’s then free to residents, community groups and garden clubs.
- Where: 900 New Jersey Avenue, S.E. (NJ and K)
- When: the website says it won’t be available til March 1, Mondays through Saturdays from 7 to 3. BUT a recent phone call indicated it’s available NOW (January 2008) and the hours are 6:30 to 5. So you might want to CALL FIRST (202/447-4257 begin_of_the_skype_highlighting              202/447-4257      end_of_the_skype_highlighting).
- How much mulch? You’re allowed to fill up to 3 30-gallon bags that you bring yourself.
- Larger amount needed? For neighborhood beautification projects and other larger needs, call 202/447-4257 begin_of_the_skype_highlighting              202/447-4257      end_of_the_skype_highlighting to make arrangements.
- Here’s the city’s press release on the subject.
- What exactly is it? Just shredded leaves, or are have they decomposed, and how much? If you’ve seen this stuff, tell us! (In the comment section below).
Takoma Park, MD provides leafmold mulch, which is chopped leaves that have decomposed for varying lengths of time. The leaves used were vacuumed up from city streets and have some trash in them, but remarkably few weed seeds. Leafmold mulch can be spread on top of soil or mixed into soil to improve it.
- It’s free for pick up by anyone. Go to their Department of Public Works at 31 Oswego Avenue, easy to find from Piney Branch Road or East-West Highway – the Mapquest site is correct for this address. Across the street from their office building is a big mulch pile – just helip yourself, 24/7. Bring your own pitchfork (the very best tool for the job) and containers.
- They’ll deliver for a charge on Fridays from 8:30 to 3:30 beginning March 30 and ending when the supply is depleted. Call Public Works to schedule a delivery at (301) 891-7615 begin_of_the_skype_highlighting              (301) 891-7615      end_of_the_skype_highlighting. Payment (check or money order only) for delivery must be mailed and received by Thursday afternoon at the Public Works Department, 31 Oswego Avenue, Takoma Park, MD 20910. The website says, “Mulch deliveries will be made to your driveway only.” then goes on to say “If you do not have a driveway, special arrangements for delivery must be arranged through the Public Works Department.”
- Resident prices for delivery are 3 cubic yards for $45; 7 or 10 cubic yards for $65.
- Nonresident prices for delivery are 3 cubic yards for $65; 7 or 10 cubic yards for $105.
- Your dump truck can also be loaded for a fee of $20 for a small truck and $30 for a large truck. Call Public Works to schedule loading at 301-891-7633 begin_of_the_skype_highlighting              301-891-7633      end_of_the_skype_highlighting.
Tip from a long-time user of Takoma Park mulch: Get the full 10 yards (if you have room to put it somewhere) and share it with neighbors. Â
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College Park, MD offers various products summarized below:
- Screened compost (called “Smartleaf”) looks like fine black soil and is used to improve the soil, less frequently as a mulch (because it’s an excellent growing medium for wind-blown weed seeds, and also because it looks like soil, not a soil cover). It’s made of leaves and grass clippings (which provides needed nitrogen for top-grade compost). It cost $15 per cubic yard.
- Unscreened “compost” is what others would call mulch. It has a little debris in it and is of a coarser grade, but it’s still great for use either on top of soil as a mulch or IN soil as an amendment. It’s free (up to 5 cubic yards) to College Park residents and $7 per cubic yard to nonresidents.
- Wood chips are great for paths or other nongrowing areas and cost $5 per cubic yard.
- Hours for pickup are M-F from 7:30am-11:30am and 1:00-3:30pm. They can load pickup trucks (with no cap) for no charge. Customers can also bring their own containers and a shovel/pitchfork if they don’t have a truck. Everyone must stop in at the main office before entering the Public Works yard.
- Delivery: charges start at $20.
- Call 301/474-4194Â Â Â
