See http://gardening.about.com/od/plantprofiles/p/Snapdragons.htm
Latin Name:
Antirrhinum majus
Common Name:
Snapdragon, Dog's/ Lion's/Toad's Mo
Overview:
Snapdragons have stalks of brightly colored flowers that are especially profuse in cooler weather. The plants start blooming at the bottom of the stalk and work their way up. The common names all derive from the way the flowers resemble opening mouths, when they are pressed on their sides. The flowers are snapped shut and require more pressure to open than a honeybee can provide, so snapdragons rely on heavier bumble bees for their pollination
Description:
Snapdragons are bushy plants with tall spikes of flower buds. Most are intensely colored and real standouts in the garden.
Leaves: The alternate, lanceolate leaves are arranged in a spiral around the stem.
Flowers: The flowers come in just about every shade, except true blue. Some are vibrant bold tones, some are soft pastels and some are subtly shaded bi-colors.
Caution: All parts of snapdragon are poisonous, if ingested.
Hardiness Zones:
Snapdragons are tender perennials that are only hardy to about USDA Hardiness Zones 8 or 9. In most areas they are commonly grown as annuals. Even when they do over-winter, they never seem to bloom as robustly as they did in their first year, which leads many people to think they are biennial, but they should form seed pods in their first year. If you're lucky, they may even self-sow.
Exposure:
They will bloom most profusely in full sun to partial shade, in the spring. Once the temperature heat up, they may stop blooming altogether. Planting them in partial shade and keeping them well watered will help them make it through the summer, to begin blooming again in fall. However they are quick to get established and it can be just as easy to replace your snapdragon plants each season.
Mature Size:
There are tall varieties and dwarf varieties and just about everything in between. Check the label or packet of the variety you are choosing.
Dwarf plants mature at a height of about 6 - 15 in. and from a dense, bushy plants with lots of flower stalks.
Tall varieties tend to be less bushy in habit, reaching a height of 30 - 48 in.
Some varieties bridge the two extremes, growing to a mid-sized 15-30 in. Of course, the actual size and fullness of the plants will also depend on growing conditions.
Bloom Period:
Snapdragons are at their best in cool weather. They can repeat bloom throughout the season, but do best in the cool of spring and fall and throughout the winter, in mild climates. Deadheading can increase the amount of buds that are set, but since the flower stalks begin blooming from the bottom up, they have a fairly long bloom duration anyway.
Suggested Varieties:
They're continually coming out with new snapdragon series. Most are sold as multi-color blends, but you can sometimes find individual colors in both seed and seedling. Some of the more popular series include:
- Arrow™ Formula Mix - Vivid colors on strong, branching stems. Grows 2' tall.
- La Bella Mix - A nice blend of colors from pale to bronze to deeply saturated. Grows 12 - 18" tall.
-
Rocket Mix - a dependable multi-colored series that grows to about 2 - 3' tall.
Design Suggestions:
Their spiky, bright colored flower stakes make a nice foil for the cooler shades of most spring flowers, like Brunnera and Bleeding Heart. Planted in clusters, they can help a border transition from the spring ephemerals to peak heat season.
The pale yellow varieties are the easiest to blend into a mixed border and work nicely with pinks, purples and even reds.
Breeders have been playing with snapdragons for a few years now and there are trailing and creeping varieties becoming more widely available. These are great filler plants for containers, baskets and tucked into walls.
Growing Tips:
Soil: Snapdragons like a neutral soil pH, between 6.2 and 7.0. As short-lived plants, they are not heavy feeders, but adding organic matter will help keep them healthy and blooming.
Planting:
Snapdragons can be winter sown, meaning you can toss the seeds out in late fall or even on top of snow, and most will germinate in the spring.
However snapdragons are most often either started indoors, 8 - 10 weeks before the last frost date, grown from cuttings or purchased as seedlings. When starting from seed, simply press the seed on the surface of the potting soil. Snapdragon seeds need light to germinate.
When seedlings have developed about 6 true leaves, pinch the top of the stem off, to encourage branching and a fuller plant. You can do this with purchased seedlings too.
Transplant snapdragons outdoors a couple of weeks before your last frost date. Snapdragons can handle a light frost or two.
Maintenance:
Regular deadheading will keep your snapdragons blooming longer. They won't need much care early in spring, but mulching to keep the soil cool and moist can help them handle summer better.
Snapdragons are tender perennials and may die off in colder climates. If they do survive the winter, prune them back by about 1/3, to encourage new growth. Don't be too disappointed if they don't last long. Snapdragons tend to go downhill after their first year and it's best to start fresh every year. Many varieties will self-seed and come back on their own, although they won't always look like the original plants you planted.
Some of the taller varieties will need staking.
Pests & Problems:
Snapdragons are affected by few pests or diseases. Rust and other fungal diseases can be a problem, especially in wet seasons. If you live in a damp or humid area, look for resistant varieties. Snapdragons may also attract aphids.
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金魚草的栽培養護技術
http://www.ew9z.com/jinyucao-zaipei-yanghu.html
金 魚草較耐寒，喜陽光，稍耐半陰，怕酷熱，略耐幹旱和微堿，喜歡肥沃、排水良好的土壤。在涼爽的環境中生長健壯。幼苗在5℃條件下通過春化階段，開花適宜溫度為15~16℃。以下介紹金魚草的栽培養護方法及注意事項：
秋播的金魚草於11月上旬定植於花壇或18~25厘米的花盆中。如果作花壇布置，栽植距離可依據品種的高矮而定，矮生種25~30厘米；中莖種30~40厘米；大花高莖種40~50厘米。
待真葉長出4~5片葉時要進行摘心，並移栽一次。作為切花栽培的大花高莖種和中莖種金魚草不可摘心，但要及時抹去側芽，以使單杆花枝獨長，花穗又粗又長。在摘心後10天噴灑0.05%~0.1%的比九（B9）有顯著的矮化效果。
除了在栽植前施足基肥外，應在生長期每2周左右追施液肥1次，但開花期應停止施肥。基肥可用骨粉、餅肥、腐葉土等腐熟的有機肥。注意幹時澆水，雨後排澇，勤除雜草，促使植株長勢旺盛。育苗期要注意間苗和保持土壤濕潤，使苗生長健壯。
金魚草較耐寒，也耐半蔭，能抵抗-5℃以上的低溫，-5℃以下則易被凍死。金魚草耐濕，怕幹旱，在養護管理過程中，澆水必須掌握“見幹見濕”的原則，每隔2天左右澆水一次。每半個月施一次腐熟的餅肥水。由於金魚草具有根瘤菌，本身具有固氮作用，因此隻需適當增施磷、鉀肥，而不需施氮肥。在花蕾出現後，用1%~2%磷酸二氫鉀噴灑，可促使花繁葉茂。另外，隨時剪去已經開過的花序，促使側枝開花，延長花期。
也可對金魚草進行促成栽培，冬春供花。辦法是提前於夏末播種，先露地栽培養護，10月間上盆，天冷時移至室內陽光充足處，白天保持22℃，夜間室溫在10℃以上，如肥水管理得當，可在元旦開花。
津京地區8月下旬秋播，當幼苗長出4~5片葉時移植摘心，小苗假植，冷床中越冬，蓋上玻璃，夜晚覆蓋蒲簾防寒，精心管理，於翌年春季5~6月開花。如在華東地區秋播露地越冬，4~5月開花。9月中旬播種於冷床越冬，翌年5月中旬進行摘心，6月下旬定植，7月初開花。
4月初於冷床春播的金魚草，9~10月開花。7月中下旬對花謝後的植株，從植株基部剪掉所有枝條，並加強肥水管理，促進萌發新枝，可於“十一”國慶期間再度開花。溫室栽培的金魚草，可使其在冬春季節開花。
金魚草的品種很多，若要區別花色和高矮品種，保持各品種的獨有特性，采種母株應分地隔離栽植，以免相互雜交。種子也要分別采收，防止混雜。一般花謝後約20天左右種子成熟，當蒴果變為棕黃色時連同花梗一起剪下，曬幹脫粒，貯存於幹燥陰涼處。
