Three Observations for Fertilizing Flowers and Precautions for Soilless Cultivation

First, observe the season

In winter, temperatures are low and plant growth is slow; most flowers are in a state of stalled growth, so fertilizer is generally not applied. Spring and autumn are the peak growing seasons for flowers, when roots, stems, and leaves grow, flower buds differentiate, and young fruits swell, all of which require more fertilizer, so appropriate additional topdressing should be applied. In summer, temperatures are high and water evaporates quickly, and it is also a period of vigorous growth for flower plants; the concentration of topdressing should be dilute, and it can be applied more frequently. At the seedling stage, more nitrogen fertilizer can be applied to promote rapid, robust growth of seedlings; at the bud stage, more phosphorus fertilizer can be applied to promote large flowers and plump seeds; at the early fruit-setting stage, fertilization should be appropriately controlled to favor fruit set.

Second, observe the variety

Different varieties of flowers have different fertilizer requirements and should be given different fertilizers. For example, osmanthus and camellia like pig manure and are averse to human feces and urine; southern flowers such as rhododendron, camellia, and gardenia are averse to alkaline fertilizers; flowers that need heavy pruning every year require a larger proportion of phosphorus and potassium fertilizers to favor the sprouting of new branches; foliage-oriented flowers can lean toward nitrogen fertilizer; flowers with large blooms, such as dahlia and chrysanthemum, should be given an appropriate amount of complete fertilizer during the flowering period so that all flowers can open, with beautiful shapes and vivid colors; fruit-oriented flowers should have water appropriately controlled during the flowering period and be given sufficient complete fertilizer during the fruit-swelling stage to achieve the expected effect; bulbous flowers should be given more potassium fertilizer to favor plump bulbs; fragrant flowers, upon entering the flowering period, should be given more phosphorus and potassium fertilizers to promote a rich floral fragrance.

Third, observe the growth condition

Especially for potted flowers, fertilization should be based on the growth condition to determine the amount. Adhere to the principle of "four more, four less, four none," namely: apply more when yellow and thin, apply more before sprouting, apply more at the bud stage, apply more after flowering; apply less when robust, apply less at sprouting, apply less when flowering, apply less in the rainy season; do not apply when leggy, do not apply when newly planted, do not apply in the height of summer, do not apply during dormancy.

At the same time, attention should be paid to the "four taboos": first, avoid concentrated fertilizer; second, avoid raw fertilizer (organic fertilizer must be fully decomposed before use); third, avoid hot fertilizer (at noon in summer, soil temperature is high, and fertilizing easily damages roots); fourth, avoid sitting fertilizer, that is, when planting flowers, do not place the roots directly on the base fertilizer at the bottom of the pot, but add a layer of soil on top of the fertilizer, and then plant the flowers into the pot.