For Healthy Plants, Test Your Garden’s Soil

For Healthy Plants, Test Your Garden’s Soil

Healthy plants are the most important part of a growing garden. And one of the best ways to keep plants healthy is to make sure the soil's chemical pH level is correct.

Every plant grows best in a specific pH level. The right pH level lets the plant take in the nutrients¹ it needs to stay healthy and grow. Because the preferred levels are different for every plant, gardeners should learn the pH requirements for each one.

For example, carnations² require pH levels between 6.7-6.9; many grasses need a pH of 6.3-6.8; tomatoes need 6.2-6.8; azaleas, 4.5-6.0; and blueberries need a pH of between 4.5 and 5.5.

What is pH?

Soil pH is the level of acidity³ or alkalinity of the soil, as measured on a 14-point number system. A pH of seven is neutral. Values below seven are acidic, and those above are alkaline. Each unit on the number system is 10 times the next value on the scale. So, a pH reading of 7.0 is 10 times higher than a reading of 6.0. That means a small 1-unit difference is a lot.

If the pH does not fit a plant's needs, it will not be able to take in enough nutrients. That is the case whether the nutrients are found naturally in the soil or added as fertilizer. A lack of nutrients will result in a lack of growth, discoloration, and even death.

The wrong pH can also poison your plants. That is because, just as it can block needed nutrients, the wrong pH can also increase the uptake of other nutrients to the point they become poisonous.

How to test your soil

To learn the pH of your soil, use products like pH testing devices or an electronic meter. They can be found at stores that sell plants, called nurseries, or online.

Kits⁵ usually contain a chemical colorant that is put on a small amount of soil. Users wait up to a minute or so, then compare any color changes to examples provided in the kit⁴.

Test strips change color when placed into a mixture of soil and water. And electronic meters provide a reading after they are placed into the soil, sometimes with water.

Depending on where you live, you can also send a small amount of soil to a cooperative extension office, which are services tied to some universities in the U.S. They likely offer soil testing for a small cost. Cooperative extension offices provide agricultural services from experts. In the U.S., they can be found at this link. Many countries have similar services at universities.

General guidelines often ask you to dig up 60 milliliters of soil from three separate areas 10 centimeters deep within the same garden bed. Then mix the soil samples to create an average. It is best to call ahead for directions.

Soil amendments⁸

You do not have to do anything if your soil's pH falls within your plant's required levels. However, if the result is outside the required levels, your next step should be to amend⁶ the soil. Use the gardening product elemental sulfur⁹ to lower pH. Use ground limestone¹⁰ to raise it.

Work the product about 20 to 30 centimeters into the soil before planting. Read the directions that come with the product to know how much to put in.

Tests provided by the cooperative extension office can offer expert guidance. Results from the office will arrive with advice about how much of which amendment⁷ needs to be added to meet your plant's preferred pH levels.

Be sure to test each area or bed in your garden separately. It is not unusual for differences to exist, even within a small area. It is also best to carry out a pH test every two or three years because soil conditions change, and amendments get used up.

Words in This Story

garden – n. an area of ground where plants (such as flowers or vegetables) are grown

specific – adj. special or particular

alkali – n. a substance that has a bitter taste and that forms a salt when mixed with an acid

unit – n. a single thing, person, or group that is a part of something larger

meter –n. a device that measures a quality or property of some substance

kit –n. a small group of tools and supplies that permit work on a project

1 nutrients   

n.（食品或化学品）营养物，营养品( nutrient的名词复数 )

参考例句：

• a lack of essential nutrients 基本营养的缺乏
• Nutrients are absorbed into the bloodstream. 营养素被吸收进血液。 来自《简明英汉词典》

2 carnations   

n.麝香石竹，康乃馨( carnation的名词复数 )

参考例句：

• You should also include some carnations to emphasize your underlying meaning.\" 另外要配上石竹花来加重这涵意的力量。” 来自汉英文学 - 围城
• Five men per ha. were required for rose production, 6 or 7 men for carnations. 种植玫瑰每公顷需5个男劳力，香石竹需6、7个男劳力。 来自辞典例句

3 acidity   

n.酸度，酸性

参考例句：

• This plant prefers alkaline soil,though it will readily tolerate some acidity.这种植物在酸性土壤中也能生存，但硷性土壤更加适宜。
• Gastric acidity would not prevent the organism from passing into the gut.胃的酸度不能防止细菌进入肠道。

4 kit   

n.用具包，成套工具；随身携带物

参考例句：

• The kit consisted of about twenty cosmetic items.整套工具包括大约20种化妆用品。
• The captain wants to inspect your kit.船长想检查你的行装。

5 kits   

衣物和装备( kit的名词复数 )； 成套用品； 配套元件

参考例句：

• Keep your kits closed and locked when not in use. 不用的话把你的装备都锁好放好。
• Gifts Articles, Toy and Games, Wooden Toys, Puzzles, Craft Kits. 采购产品礼品，玩具和游戏，木制的玩具，智力玩具，手艺装备。

6 amend   

vt.修改，修订，改进；n.[pl.]赔罪，赔偿

参考例句：

• The teacher advised him to amend his way of living.老师劝他改变生活方式。
• You must amend your pronunciation.你必须改正你的发音。

7 amendment   

n.改正，修正，改善，修正案

参考例句：

• The amendment was rejected by 207 voters to 143.这项修正案以207票对143票被否决。
• The Opposition has tabled an amendment to the bill.反对党已经就该议案提交了一项修正条款。

8 amendments   

（法律、文件的）改动( amendment的名词复数 )； 修正案； 修改； （美国宪法的）修正案

参考例句：

• The committee does not adequately consult others when drafting amendments. 委员会在起草修正案时没有充分征求他人的意见。
• Please propose amendments and addenda to the first draft of the document. 请对这个文件的初稿提出修改和补充意见。

9 sulfur   

n.硫，硫磺（=sulphur）

参考例句：

• Sulfur emissions from steel mills become acid rain.炼钢厂排放出的硫形成了酸雨。
• Burning may produce sulfur oxides.燃烧可能会产生硫氧化物。

10 limestone   

n.石灰石

参考例句：

• Limestone is often used in building construction.石灰岩常用于建筑。
• Cement is made from limestone.水泥是由石灰石制成的。