Mulch is simply organic materials (usually bark) that is surface spread over your garden to assist moisture retention and keeping the soil cooler. It eventually composts and needs to be re-done.
Mulching is not composting, though you can (and should) use compost in your mulch.
Mulch has multiple benefits:
• keeps weeds down
• reduces watering needs
• encourages plant growth – less root stress.
• helps prevent erosion (from heavy rains
• assists nutrient retention
• assist aeration
Additionally, mulch in conserving soil moisture, becomes an action that is environmentally friendly – in that its saves water.
The main use is to conserve moisture in the soil, and to moderate the soil temperature.
In reducing the growth of weeds you are saved time and effort which you can devote to chores you prefer.
In summary a good covering of mulch:
1. Prevents weed germination and growth.
2. Reduces evaporation from the soil surface and hence reduces losses from bare soil areas.
3. Provides for a more even soil temperature.
4. Can help water holding capacity and improve soil structure
5. Activates microbiological and worm action.
6. Protects the soil from erosion
7. Keeps fruits and vegetables clean
8. Keeps feet clean, allowing access to garden even when damp
9. Provides a “finished” look to the garden
Types of Mulch
Mulch falls into two categories: Landscape mulch and soil conditioning mulch.
Landscape mulch is decorative, even sizes, slow to break down and does not move around. It is usually some form of thicker bark pieces.
Soil conditioning mulches are laid to add nutrients and so break down more quickly.
• Mulches can also be used to alter or maintain a required ph level in a soil – adding pine bark to alkaline soils will eventually make them more acidic and suitable for acidic loving plants such as azaleas, gardenias and so on. They have real nutrients in them. Pine needles also work well and break down faster.
• Pea straw and sugar cane are rich in nitrogen and quick to decompose.
Organic: This basically is your compost: lawn clippings, newspaper, leaves, food scraps, and any other degradable organic matter. This will decay over time and require replacing in order to retain the benefits. Issues with organic Mulches may be the acidity of the plant and food matter, and that it may require treatment prior to placing on the garden.
Pebbles, Gravel and Stone
Naturally, these have no nutrients and will not break down. Used for decorative purposes. Putting plastic under them will keep only some weeds away – but it prevents nutrients from entering the soil beneath so avoid plastic covering.
Applying Mulch
Basically, when needed – if the last lot laid down has broken down too much. You can use a schedule if you like – but do it when you see more weeds appearing than usual and before the summer heat comes on.
In cold, frosty areas it will help warm the soil for Spring plantings.
Mulch provides an insulating barrier between the soil and air, helping moderate the temperature of the soil. Thus in summer it will be cooler and warmer in autumn and winter. It will also ameliorate the effects of freezing in the soil.
Of course, the reverse also works – come the spring mulched soils will take longer to warm up, so remove it for a while if you want to plant spring veg and flowers. Germination occurs better in warmer soils. If too cool, germination will be slowed and wet rot could occur to seeds and seedlings.
Mulches used to help moderate winter temperatures can be applied late in the fall after the ground has frozen but before the coldest temperatures arrive.
Mulches used to protect plants over winter should be loose material such as straw, hay, or pine boughs that will help insulate the plants without compacting under the weight of snow and ice.
Mulching helps prevent the rapid fluctuations in soil temperature and reduces the chances of exposing roots.
General Guidelines
• Leave an inch or so of space next to plants to help prevent diseases flourishing from excessive humidity.
• Weed the garden bed first before spreading mulch.
• Newspapers – only use black ink pages – color dyes may be harmful to soil microflora and fauna
• Best Levels – for bark, wood chips, leaves – about 3-5 inches thick. Paper – ¼ inch and compost about 3-4 inches thick
• Don’t use plastic sheeting – it prevents any soil conditioning and rarely keeps weeds out for long anyway.
If using bark as a mulch – ensure that it is both disease and pest free. Termites hidden in bark will infest other areas of the yard and house.
Recommended Reading: Composting and Mulching Saves Money
“Let it Rot!: The Gardener’s Guide to Composting (Third Edition)” (Storey’s Down-to-Earth Guides)
A readable, quietly humorous introduction to composting, this covers reasons to compost; differing approaches; how decomposition works; various methods, ingredients, and containers; how to speed decomposition; and how to use the end result. Campbell is an experienced gardener, and the book goes into great detail, but the text remains clear and interesting.
This is from Amazon – the prices constantly change due to discounts being added
