Timing, Methods and Precautions for Repotting Flowers

Simple repotting and transplanting techniques can greatly increase the survival rate of plants. How to repot flowers? What should be noted when repotting? What is the best time to repot flowers? Household potted plants should be repotted (soil changed) every 2-3 years. Repotting (changing the soil) not only helps stimulate plant vitality and enables better nutrient absorption, but also helps accelerate the growth of potted plants.

Methods and Precautions for Repotting Flowers

1. Principles of Repotting Flowers

The purpose of repotting is to improve the nutritional condition of the plant. Generally, annual and biennial herbaceous flowers need to be repotted 1-2 times before flowering. Perennial flowers are repotted once a year; woody flowers can be repotted once every other year. For example, Aglaia odorata (mock lime), Rosa chinensis (Chinese rose), Jasminum sambac (jasmine), Euphorbia pulcherrima (poinsettia) and Hibiscus rosa-sinensis (Chinese hibiscus) all need to be repotted once a year; Camellia japonica (camellia), Cymbidium (orchid) and Rhododendron (azalea), although they grow more slowly, should also be repotted once every other year.

For large perennial potted flowers, as the root system gradually develops and due to years of watering, the soil in the pot gradually decreases, the potting soil becomes increasingly compacted, its air permeability gradually declines compared with before, and the nutrients in the soil also gradually become insufficient for the plant's needs. Therefore, even if large potted flowers are still kept in their original pots, the soil should be changed at least once every 2 years, trimming away some damaged roots, overly long or overly dense roots, rotten roots and roots damaged by pests and diseases, and adding some new soil, so as to help the plant continue to grow larger.

The best time to repot flowers is during the plant's dormant period. Woody and perennial flowers can generally be repotted in March, while early-spring flowers should preferably be repotted after flowering.

2. Steps for Repotting Flowers

(1) Turn the flower pot upside down and pat the bottom of the pot so that the plant's root ball comes out whole with the soil. If the potting soil is too compact, you can use an iron rod or a screwdriver inserted around the edge of the pot to loosen the soil. Then tip out the root ball.

(2) Trim the bottom of the plant's root system, removing old roots, dead roots, diseased roots and overly dense, tangled roots. Thick strong roots that affect placement in the pot (which only serve to anchor the plant, since only the fine fibrous roots absorb nutrients) can also be appropriately shortened.

(3) Cover the drainage hole at the bottom of the flower pot with window screen mesh to prevent insects, then press a stone on top. Then use soil mixed with base fertilizer to fill the bottom of the pot to a depth of about 2CM (so that the plant's roots have room to grow and their vitality is stimulated), and firm it down. Then place the plant in the pot and cover with soil.

(4) After planting, firm the surface layer of soil in the pot (so that the plant's roots are in close contact with the soil and can absorb nutrients and water), and then water it (the settling water). For the initial watering, it is recommended not to fertilize; the plant should be given a period of time to adapt (establish itself, about half a month or more) before applying a light fertilizer. Water thoroughly, place it in a ventilated, shaded spot for more than a week, and then resume normal care.

Precautions for Repotting Flowers

(1) During the manufacture of flower pots, the drainage hole at the bottom often has an upward-facing rim. If this rim is not removed, it will affect drainage during the rainy season, so it should be knocked off when repotting. When potting, a piece of plastic window screen can also be placed at the bottom to prevent white grubs and earthworms from entering the pot.

(2) The root ball tipped out during repotting must have its outer layer of old roots cut away with a sharp gardening trowel, and the surface soil of the roots should also be loosened with a trowel. Otherwise, the root system will curl and wind around the walls of the pot without extending, making it susceptible to drought, waterlogging, cold and heat changes, and the plant will often develop poorly.

(3) After repotting with new soil, the potting soil must be firmed down to prevent hollows from appearing after watering, which would affect the roots' absorption of water. Also, a watering rim must be left, so that the pot is not so full of soil that there is no place to hold water.

(4) Watering must be thorough. For the first watering after repotting, it is best to use the immersion method: place the potted flower in a basin of water, and once the surface of the potting soil is moist, take it out and set it down. After the first watering, water again only when the potting soil has dried to the point that the surface turns pale, following the principle of "no watering when not dry."

The best time to repot flowers.

Generally, repotting should be done during the dormant period of the flowers, from late February to early March in early spring, or preferably as late as early April, when the flowers' metabolism is slow. For spring-flowering plants, repotting and soil changing should be done when the flower or tree begins to stir into growth or before it grows; at this time the plant is in its dormant period and has low demands for water and fertilizer, so damaging some fibrous roots will not affect the survival rate, nor will it cause leaf drop or extensive leaf drop. If such a situation occurs, water to prevent drying out, increase the frequency of misting the leaves, and temporarily stop fertilizing. After a period of adjustment, the yellowing and leaf drop will stop, the plant will recover its vitality, and it will grow new leaves again.