A Detailed Guide to Flower Repotting Methods, the Best Time, and Precautions

Efficient and simple repotting and transplanting techniques can greatly increase the plant survival rate. How do you repot flowers? What should you pay attention to when repotting? When 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 so nutrients are absorbed better, it also helps accelerate the growth of potted plants.

1. Methods and precautions for repotting flowers

1. Principles of repotting flowers

The purpose of repotting is to improve the plant's nutritional condition. 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), Chinese rose, jasmine, poinsettia, and hibiscus all need to be repotted once a year; camellia, orchid, and azalea, although they grow more slowly, should also be repotted once every other year.

For large perennial potted flowers, because the root system gradually becomes more developed and because of 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 kept in the original pot, the soil should be changed at least once every 2 years, trimming away some damaged roots, overly long and 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 time for repotting flowers is best during the plant's dormant period. Woody and perennial flowers can generally be repotted in March, while early-spring flowers should be repotted after flowering.

2. Steps for repotting flowers

(1) Turn the flower pot upside down and pat the bottom of the pot so the plant's root ball comes out whole with its soil. If the potting soil is too tight, you can use an iron rod or a screwdriver inserted around the edge of the pot to loosen the soil. Then tip out the soil 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 fitting into the pot (they only serve to anchor the plant itself, while it is the fine hair roots that absorb nutrients) can also be appropriately shortened.

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

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

2. Precautions for repotting flowers

(1) During the making of a flower pot, the drainage hole at the bottom often has an upward 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, you can also use a piece of plastic window screen as a bottom liner, which can prevent white grubs and earthworms from entering the pot.

(2) When repotting, the root ball tipped out must have its outer layer of old roots shaved off with a sharp garden trowel, and the surface soil of the root system also needs to be loosened with a trowel. Otherwise, the root system will curl in bends around the pot wall without extending, making it prone to the effects of drought, waterlogging, cold, and heat changes, and the plant often develops poorly.

(3) After repotting with new soil, the potting soil must be firmed down to avoid hollows appearing in the potting soil after watering, which would affect the root system's absorption of water. Also, a watering rim must be left, so that there is a place for the water to stop because the pot is not completely full of soil.

(4) Watering must be thorough. For the first watering after repotting, it is best to use the soak method: place the potted flower in a basin of water, and take it out to set down once the surface of the potting soil is moist. After the first watering, wait until the potting soil dries to the point that the surface turns white before watering again, following the principle of "no dry, no water."

3. When is the best time to repot flowers?

Generally, repotting is best done during the plant's dormant period, from late February to early March in early spring, and no later than early April, when the flower's metabolism is slow. The time for repotting and changing soil for spring-flowering plants should be when the flower or tree is stirring into growth or before it grows; at this time the plant is in its dormant period, has low demands for water and fertilizer, and damaging some roots will not affect the survival rate, nor will it cause leaf drop or large-scale leaf drop. If such a situation occurs, water to prevent drying out, increase the number of times you spray the leaves, and suspend fertilizing at the same time. After a period of adjustment, the yellowing and leaf drop will stop, the plant will regain its vitality, and it will grow new leaves again.