Home gardening

Japanese: 家庭園芸 - かていえんげい

Gardening is a form of home gardening that is undertaken for the enjoyment and enrichment of daily life. It refers to the cultivation of vegetables, flowers, fruits, etc., as both a hobby and a practical benefit. In recent years, there has been a quiet boom in gardening, not only in the garden, but also in people who do not have a garden, by utilizing small spaces such as rooftops, balconies, or even indoors to bring greenery into their lives. There has also been an increase in people renting community gardens to create fields. Growing, appreciating, and harvesting plants is a fun and interesting experience that differs from buying ready-made plants, and can even be a way to bring the family together. Plants have various characteristics, such as some that prefer full sun, some that can grow in the shade, some that are sensitive to heat or cold, and some that can be grown without soil, so it is important to choose a type that suits the environment.

When cultivating it, it is important to pay attention to the following points:

[Yasuo Hori]

soil

Except for special cultivation methods such as hydroponics (nutrient solution cultivation), soil is necessary for plant cultivation to support the plants and to supply them with nutrients and water. There are good and bad soils for plant growth. Good soil is fertile and has good drainage and water retention. Soil that stores humus and nutrients (fertilizer) and has a granular structure is good. Soil with a granular structure has good breathability and drainage because the particles gather together to form small clumps, and the small clumps have capillary pores, so they have water retention. The degree of fertilizer absorption varies depending on the soil quality, but the higher the clay content, the greater the fertilizer retention, and the more coarse-grained sand, the less fertilizer retention. To prepare soil for cultivation, it is important to till it well. And mixing in organic matter such as compost or leaf mold as a soil fertility retaining material can promote the formation of granular soil.

Most of the soil in Japan is acidic or slightly acidic, but many plants dislike acidic soil. Spinach is well known for growing poorly in acidic soil, but other plants include those from the Solanaceae, Cucurbitaceae, and Chenopodiaceae families. In addition, if the soil is made alkaline with a pH of 7 or higher, the absorption of trace elements is poor and deficiencies can occur. In general, plants grow well when the pH is between 5.5 and 7.0. Lime is spread to improve acidic soil. Plants that grow in the same soil for many years will grow poorly and the yield will decrease. This is called a decline in soil fertility or aging. The causes are thought to be the leaching of bases in the soil by rainwater or irrigation, the remaining by-products from the excessive use of chemical fertilizers, and organic acids released from the roots of plants. To prevent this, organic matter such as compost or livestock manure can be mixed into the soil and lime can be spread, which can be effective to a certain extent.

[Yasuo Hori]

Sunshine

Higher plants use the sun, air, and water as nutrient sources to create the nutrients they need to grow. Therefore, a sunny location is the first condition for producing beautiful flowers, delicious fruits, and vegetables.

[1] Summer sunlight encourages vigorous growth of tropical plants, but conversely, heat causes poor growth for plants that prefer cooler conditions. Plants with thin, weak roots cannot absorb the amount of water that evaporates from the leaves, so they die or, in pots, suffer leaf burn. To prevent this, you can lay straw mulch or vinyl sheeting. For potted plants, use reed screens or cheesecloth to block the light. On balconies, radiant heat from the concrete floor can make the area very hot and dry, so lay a bamboo slat or mat.

[2] In winter, the daylight hours are short, the sunlight is not strong, and the temperature drops, so tropical plants that grew vigorously in summer stop growing or grow slowly because their respiration rate decreases. However, even with little sunlight, growth can be maintained by controlling the temperature in a greenhouse or warm place indoors. Traditionally, when growing plants in winter on fields, high ridges are made on the east and west sides to make use of radiant heat to raise the ground temperature. When growing plants on a balcony, etc., the plants will wilt if exposed to dry, cold winds, so it is best to water them during the day and cover them with insulation at night.

[Yasuo Hori]

Irrigation

More than 90% of a plant's body is water. Water is the most important element for plants, and they obtain most of it from the soil. Soil moisture has the following roles and effects: (1) it helps the roots absorb necessary nutrients, (2) it plays a role in regulating soil temperature, and (3) it activates microorganisms in the soil. There is an old saying that goes, "watering a plant for so many years," and watering a plant in a way that is appropriate for its growth is difficult, and it is even considered a kind of skill, especially with potted plants. Even in fields or flower beds, if plants are watered when the soil temperature is high in summer, the water will become so hot that it will burn the roots, causing damage, so care must be taken to water plants in the mornings and evenings when the temperature has dropped.

[Yasuo Hori]

fertilizer

Plants require 16 elements, including nitrogen, phosphorus, potassium, lime, magnesium, and trace elements, to grow normally. In particular, due to their function within the plant body, nitrogen is generally referred to as leaf fertilizer, phosphorus as fruit fertilizer, potassium as root fertilizer, and lime as body building fertilizer. Also, since plants cannot absorb fertilizer if a large amount is applied at once, it is effective to divide it into base fertilizer and top dressing according to the plant's growth. Trace elements are contained in the soil to a certain extent, so no special fertilization is required, but applying organic matter is very effective.

[Yasuo Hori]

Pests and diseases

It is important to take appropriate preventative and control measures early on when pests and diseases occur in plants, because once the damage has become extensive, it is too late. Since pests and diseases occur in the roots, trunks, leaves, and flowers, it is important to understand their characteristics, identify the cause, and spray insecticides and fungicides in the correct concentrations and using them correctly.

[Yasuo Hori]

"Gardening Encyclopedia", 13 volumes (1980-81, Kodansha)" ▽ "Garden Series" (1975-, Seibundo Shinkosha) ▽ "Gardening Handbook", 42 volumes (1976-84, Hikari no Kuni)"

[Reference] | Home gardening

Classification of home garden plants (vegetables)
©Shogakukan ">

Classification of home garden plants (vegetables)

Classification of home garden plants (flowers)
©Shogakukan ">

Classification of home garden plants (flowers)

Classification of home garden plants (fruit trees, ornamental plants, etc.)
©Shogakukan ">

Classification of home garden plants (fruit trees, ornamental plants, etc.)

Types of garden soil (natural products)
©Shogakukan ">

Types of garden soil (natural products)

Types of garden soil (processed products)
©Shogakukan ">

Types of garden soil (processed products)

Types of fertilizer
©Shogakukan ">

Types of fertilizer

Functions of the main components of fertilizer
©Shogakukan ">

Functions of the main components of fertilizer

Soil grain structure and aggregate structure
©Shogakukan ">

Soil grain structure and aggregate structure

Main pests and diseases
©Shogakukan ">

Main pests and diseases

Main pesticides used in home gardening
©Shogakukan ">

Main pesticides used in home gardening

Pests and diseases by plant part
©Shogakukan ">

Pests and diseases by plant part

Main gardening tools
©Shogakukan ">

Main gardening tools

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

Japanese:

家庭生活のなかで潤いや楽しみのために行う園芸で、趣味と実益を兼ねて野菜や花卉(かき)類、果物などを栽培することをいう。庭での栽培はもちろんのこと、庭がない場合でも、屋上やベランダあるいは室内などの狭い空間を利用して、生活に緑を取り入れることが、近年静かなブームとなっている。また、市民農園を借りての畑づくりも増えてきている。植物を育て、観賞し、そして収穫することは、できあいのものを買うのとは違った楽しさ、おもしろさがあり、ひいては家庭のだんらんの一つにもなりうるものである。植物には、日当りを好むものや日陰でも育つもの、暑さに弱いものや寒さに弱いもの、土がなくても育てられるものなど種々の性質があるので、環境にあった種類を選ぶことがだいじである。

　栽培にあたっては、次のような点に気をつけることがたいせつである。

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土壌

植物の栽培には、水耕栽培（養液栽培）などの特殊なものを除いて、植物が倒れないように支えるためと、養分や水分を供給するために土が必要である。植物が生育するうえによい土もあれば悪い土もある。よい土とは、肥沃(ひよく)で排水のよい保水性のあるものである。腐植と養分（肥料分）を蓄えている土で、団粒構造をもつものがよい。団粒構造をもった土は、粒子が集まって小さな塊となっているため、通気性と排水がよく、小さな塊の中には毛管孔隙(こうげき)があるので、保水性がある。土質によって肥料の吸着度合いが異なるが、粘土含量が多くなるほど保肥力が増し、粒子の粗い砂などが多くなると保肥力は少なくなる。栽培のための土づくりとしては、よく耕すことである。そして地力保持材として堆肥(たいひ)や腐葉土などの有機物を混入すると団粒化を促すことができる。

　わが国の土壌の多くは酸性ないし弱酸性であるが、植物には酸性土壌を嫌うものが少なくない。酸性土壌での生育不良を示すものとしてホウレンソウが有名であるが、そのほかにナス科やウリ科、アカザ科のものなどがあげられる。また、pH7以上のアルカリ土質にすると、微量要素の吸収が悪くなり欠乏症をおこすことがある。一般的にはpHが5.5～7.0のときが生育良好を示す。酸性土壌の改良には石灰などを散布する。同じ土で何年も植物を栽培すると、生育不良になったり収穫が低下する。これを地力の低下とか老化という。原因は、雨水や灌水(かんすい)によって土中の塩基類が溶脱したり、化学肥料の多用による副生物の残存、植物の根から出る有機酸によるものとされている。防止策としては、堆肥や家畜糞(ふん)などの有機物を混入し、あわせて石灰を散布することで、ある程度効果をあげることができる。

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日照

高等植物は、太陽と大気、水を栄養源として生育に必要な養分をつくる。したがって美しい花やおいしい果実、野菜をつくるためには、日当りのよい場所であることが第一の条件である。

〔1〕夏の日照は、熱帯性の植物の生育を旺盛(おうせい)にするが、逆に冷涼な条件を好む植物にとっては暑さが生育不良の原因となる。根が細く弱い植物は葉から蒸発する量の水を吸い上げられないため、枯死するか鉢物では葉焼けといった現象がおこる。これを防ぐには敷き藁(わら)やビニルシートなどを敷くとよい。鉢物ではよしずや寒冷紗(かんれいしゃ)などで遮光する。ベランダでは、コンクリート床からの輻射(ふくしゃ)熱のために高温となり乾燥が激しいので、簀子(すのこ)やマットを敷く。

〔2〕冬は日照時間が短く日差しも強くなく温度も低下するので、夏に生育旺盛だった熱帯性の植物は呼吸量が減少するため、生育が中断したり緩慢になる。しかし、日照が少なくても、温室や室内の暖かいところで温度管理をすれば、生育を維持することができる。昔から畑地の冬作では、東西に高うねをたて、輻射熱を多く利用して地温を上げるくふうが行われている。ベランダなどでの栽培は、乾燥した寒風に当たると植物が萎縮(いしゅく)するので、灌水は日中に行い、夜間は保温材などで囲うのがよい。

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灌水

植物体は90％以上が水分とされている。水は植物にとってもっとも重要なもので、そのほとんどを土中から得る。土壌水分は、(1)必要な養分を根から吸収するための手助けをする、(2)地温の調節的役割を果たす、(3)土壌中の微生物を活性化する、などの役割、効果をもっている。昔から、水やり何年ということばがあるように、植物の成長に適した水やりはむずかしく、とくに鉢物では一種の技術とされるほどである。畑地や花壇でも、夏の地温が高いときに灌水すると、根焼けといって水が高温になり根を傷めるので、水やりは朝夕の気温が下がったときに行うなどの注意が必要である。

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肥料

植物が正常に生育するためには、窒素、リン酸、カリ、石灰、マグネシウムや微量要素など16元素が必要とされる。とくに植物体内での働きから、一般に窒素は葉肥(はごえ)、リン酸は実肥、カリは根肥、石灰は体づくりともいわれる。また、一度に多量の肥料を施しても吸収できないので、生育にあわせて元肥と追肥に分けるのが有効である。なお、微量要素はある程度土中に含まれているので、とくには施肥を要しないが、有機物を施用すると効果は大きい。

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