Benefits of Mulching

Mulch is important to farmers. Mulch is a protective cover of material that is spread on top of soil. It is usually made out of organic material, like crop waste. Farmers may keep the remains of maize or other crops on top of the soil. This creates mulch on the soil surface. The plant remains help protect the soil against wind and water damage. This is called conservation tillage.

Mulching is one of the best things people can do for their plants. Mulch not only protects the soil against wind and water damage. It also helps keep the soil from getting dry, and reduces the need for watering plants. It also limits temperature changes in the soil. And it stops unwanted plants, or weeds, from growing.

Organic mulch improves the condition of soil. As the mulch breaks down, it provides material which keeps the soil from getting hard. This improves the growth of roots and increases the movement of water through the soil. It also improves the ability of the soil to hold water. Organic mulch contains nutrients for plants. It also provides a good environment for earthworms and other helpful organisms in the soil.

The best time to add mulch depends on your goal. Mulch provides a thick barrier between the soil and the air. This helps to reduce temperature changes in the soil. As a result, mulched soil will be cooler than other soil in the summer. Mulched areas usually warm up more slowly in the spring and cool down slowly in autumn. In winter, the mulched soil may not freeze as deeply as other soil.

Mulch used to help moderate the effects of winter weather can be added late in autumn. The best time is after the ground has frozen, but before the coldest weather arrives. Spreading mulch before the ground has frozen may attract small animals searching for a warm place to spend the winter. Delaying the spreading should prevent this problem. The animals will probably find another place to live.

The United States Department of Agriculture says it is easy to find organic mulch materials. Cut-up leaves and small pieces of tree bark can be used. Grass cuttings are also a good mulch for plants. Mulch from newspapers works well in controlling weeds.

Source:
VOA News

Plants to Avoid—Invasive Exotic Plant Species

Many of the plants we use in landscaping today did not originate from this country. They were introduced either deliberately for their beauty or food value, or unintentionally in seed, soil or ballast water. Most of these “exotic” plants stay where they are planted and do not invade natural areas. However, some exotics have become invasive. And because no natural controls exist here, they take over and threaten native plant communities, degrade fish and wildlife habitat, restrict recreational activity and reduce agricultural yields.

Scientists estimate that invasive weeds are spreading at a rate of about 1,900 hectares (4,600 acres) each day on public lands in the West. That would cover an area larger than the state of Delaware in just one year! Invasive weeds also have special characteristics that help them get a head start on native plants. Many have a long root system, which makes it easier for the plant to get water. (Especially in dry areas, much of the water supply is located deep underground.) Many weeds are tall and bushy and have hundreds of seeds. The seeds can travel great distances by wind or water, or they can “hitchhike” on wildlife, horses, livestock, and people–and on people’s cars and trucks, too. Some invasive weeds grow tall quickly and keep the sun from reaching smaller, slow-growing native plants. Still others grow in dense patches, crowding out native plants.

A good example of an exotic invasive plant is Purple Loosestrife. It is an herbaceous plant that lives in wetlands, shorelines and roadside ditches and has a pretty purple spike that blooms in mid-summer.

Dense stands of purple loosestrife have colonized many wetlands, replacing native food and cover plants that wildlife species depend on. According to the U.S. EPA, wetlands infested with purple loosestrife lose as much as 50% of their original plant populations. This limits the variety of food and cover available to birds and other wildlife, causing them to move or disappear from a region altogether.

So how do you determine if a plant is invasive? Follow these three easy steps:

Step 1. Use Native Species

If you want to make sure the plants you are using don’t end up taking over the adjacent woods or wetland, just use native plant species. Although some natives are aggressive and will colonize your garden quickly, at some point natural controls will keep the plant in check if it moves into the wild.

Step 2. Ask Yourself These Questions

The Maryland Native Plant Society evaluates exotic plants for a garden this way:

• Does the exotic plant naturalize or self-sow? If the plant spreads its seeds far by wind or water, don’t plant it. Purple loosestrife spreads through wetlands this way.


• Is the exotic plant a wildlife food plant? If yes, then wildlife will spread the seed around, and it is not a good choice. Autumn olive was originally planted for wildlife.
  
  
• Is the exotic plant a rapidly spreading groundcover? If so, don’t plant it next to naturalized areas. An example of this is a woodland floor covered with English Ivy or Myrtle.
  
  
• Is the exotic plant low maintenance, cold-hardy, tolerant of extreme water conditions, shade tolerant and pest-free? We generally think of these as positive traits in landscape plants! But it also means this exotic has no natural controls and should not be used. Crown vetch is a good example of this type of exotic.
  
  
• Does the exotic plant have the ability to kill or suppress growth of surrounding plants by shading them out, chemically poisoning them, or out-competing them for food and water? If so, you don’t want this plant in your garden! The shade and roots of Norway maples make it very difficult for any other plant (including grass) to grow beneath them. Plants with the above characteristics are not only problems for natural areas, but are problems for gardeners who have to work hard to control them in their yards.
  

The “Do No Harm” Philosophy

When deciding which plants to add to your garden, hold fast to the “Do No Harm” philosophy. This idea says that whatever type of plant you choose, native or non-native, make sure that plant will stay where it’s put, and will not overtake your adjoining woodland or wetland. Most native species have natural forces at work to check their spread. Non-natives, being out of their natural range, don’t. Therefore, our choice of species becomes the “natural force” that keeps the non-natives in check.

Related topic: Benefits of Landscaping with Native Plants

Source:
U.S. Environmental Protection Agency

Oxalis - A Cute Little Curse

Here in the Bay Area of California where I live almost anyone with a piece of dirt can tell you about oxalis, or wood sorrel, a cute shamrock-leaved little plant that grows and spreads with amazing speed. In fact, it's also called a shamrock, and the first time I saw it leprechauns and St. Patrick's Day did indeed spring to mind. The next several times I saw it, however, my mind turned to less kindly thoughts of eradication.

Some would charitably describe oxalis as a ground-cover. Most, including me, would probably call it a weed. Not long after it gets a foothold in your garden, you'll suddenly discover it's taken over. As Sunset's Western Garden Book puts it mildly, oxalis "Can be somewhat invasive in its favored woodland conditions." Actually, it appears to be invasive in plenty of other conditions: lawn conditions, garden conditions, that-damp-spot-under-the-hose conditions, and on and on.

There are quite a few varieties of oxalis, sporting yellow, light violet, or white flowers, all of which are very pretty to look at, but which rapidly lose their appeal as they appear by the hundreds in places where you were trying valiantly to grow something else. If you have an oxalis/wood sorrel/shamrock infestation, a great online resource, the Berkeley Parents Network has the following advice from their aptly-titled discussion "Oxalis - demon weed from hell." (No, you don't have to be a parent to use the site :-) It comes from Anthony Garza, Supervisor of Horticulture at the UC Botanical Garden in Berkeley - so he knows his stuff:

"Really, SPRAY [Roundup herbicide] and PULL and MULCH again and again if you wish to have anything resembling a landscaped yard that is under control. Organic controls would exclude the Roundup, and most have not had any long-term luck with those methods. You will have to concede with living with a certain level of infestation if you are not willing to use a glyphosate-based herbicide." Read Anthony's complete post.

Or if that's too much trouble, you could just decide to sit back and enjoy the invasion. There are certainly a lot uglier weeds than oxalis...here's a great illustration of one variety, Goat's Foot Wood Sorrel:


(Image courtesy of the US Department of Agriculture's National Agricultural Library)