页面标题

为树木和灌木选择护根物

文本

你喜欢折磨植物吗? If yes, get some rock mulch and put it around your plants.

岩石覆盖物对植物没有任何作用. A rocky bed may look good to us, but the plants are crying in pain.

用碎树皮代替. 它之所以更好，有很多原因:

Left image close up of bush with rock mulch showing damage. Right image a bush without leaves on top because of rock mulch damage.
This burning bush got burned to death (excuse the pun) in a bed of rock mulch. The birch at right suffered from heat generated by rock mulch, which contributed to a severe infestation of bronze birch borer.
  1. 切碎的树皮可以调节温度. It will keep a plant cooler during summer and warmer during winter. 完美的! 岩石覆盖物是热陷阱. It will scorch plants during the summer and make plants uncomfortable in winter, too. 对热敏感的植物，比如桦树, 山灰和玉簪, the use of rock mulch may contribute to premature death.
  2. 切碎的树皮能改善土壤. It enhances soil structure, leading to an aerated soil that can hold onto nutrients and moisture. Although there can be a short-term loss of nitrogen, the bark will eventually compensate for this and add more nutrients. 岩石覆盖物对土壤有害. Its heavy weight compacts the ground and destroys air pockets needed for roots to grow. Also, rocks add no nutrients to the soil.
  3. Both mulch types protect plants from lawn mowers, but the jagged edges of rock mulch can cause harm on tender bark.
  4. 两种地膜都能保持水分, but the heat generated from rock mulch creates greater drought stress on the plants.

Rock mulch is terrible for plants—so why do we use it?

Some gardeners worry about weeds growing in shredded bark. True, shredded bark will allow more weeds compared to a barrier of jagged rocks and landscape fabric. However, weeds in shredded bark are sparse and pull out easily. A spray of Roundup once a year may be applied to control tough weeds like quackgrass.  

Some gardeners are frustrated that shredded bark can blow away. Rarely is this a significant problem if the mulch is applied properly:

Left picture shows the proper way to mulch a tree, gradually building to a depth of 4 inches around tree. The right image shows mulch incorrectly piled very high near the base of the trunk.
The right and wrong ways to mulch a tree. Left: Place minimal mulch at the trunk and gradually build it to a depth of up to 4 inches around the perimeter. Right: Avoid accumulating mulch near the trunk since this leads to trunk rot and attracts rodents that nest in the mulch and feed on the bark.
  • Shredded bark should be applied in a circle at least three feet wide; the wider the better. Take the mulch all the way out to the dripline, if you want. The mulch should be minimal at the trunk and gradually increase in depth to three to four inches around the perimeter.
  • Do not heap mulch around the trunk—these “volcano” mulch piles harm the tree by causing trunk rot and encouraging mice to nest near the trunk.

The next time you plant a tree or shrub, show it some love and surround it with shredded bark. You will be rewarded with a happy, healthy plant.  

Revised from an article published in the NDSU Yard & 2013年8月16日园林报告.

写的 汤姆卡尔布, 扩展 Horticulturist, North Dakota State University. 发表在NDSU庭院 & 花园报告，2016年6月30日. Photos were made available under Creative Commons licenses specified by the photographers: 汤姆卡尔布, NDSU; 扩展.org:花园、草坪和风景