How to propagate geraniums by cuttings? Master these key tips
Geraniums are mainly propagated by cuttings. Cuttings taken in April to May will bloom in autumn; cuttings taken in September to October will bloom in winter and spring. The stems are tender, juicy and hollow, and rot very easily after cutting; the thicker the stem, the higher the rot rate. Therefore, the following points should be noted when propagating by cuttings:
(1) Cutting time.
Geranium cuttings are usually taken in spring from April to May or in autumn in mid-to-late September, when the temperature is suitable. In summer, however, the temperature is high and the humidity is great, so the cuttings rot easily; in winter the temperature is low and rooting is slow.
(2) Cutting and handling of the cuttings.
When selecting cuttings, cut the growing tips of vigorous shoots and the tender stems below them from mother plants that flower consistently, flower freely, are true to variety and free of pests and diseases; the length is 7 to 10 cm. Do not insert the cuttings immediately after cutting; let them dry for at least a full day and night, and insert them only after the cut surface has dried. Alternatively, pinch out the growing tip of the mother plant intended for cuttings in advance; after new side shoots have grown, cut from the base of the new side shoots, close against the mother plant. Such cuttings have a small cut surface and are solid rather than hollow inside, readily form callus tissue, root quickly, rarely rot and have a high survival rate.
(3) Cutting and after-cutting management.
Clean river sand, vermiculite, perlite and the like can be used as the cutting medium. Insert to a depth of about 1/3 of the cutting's length, and cut off the large leaves on the cutting, leaving only 1/2 of a small leaf, to reduce water evaporation. After inserting, water thoroughly and first place in a cool spot away from direct sunlight; keep the medium temperature at 15°C, and roots will form in about 1 month. Once rooted, pot them up promptly.
Geranium growing methods and precautions, geranium pictures
Geranium growing methods and precautions
Pelargonium, also known as shilazihong, rulazihong, rilanzihong and yangkui, belongs to the Geraniaceae family and is a genus of flowering plants including about 230 species of perennial succulent, subshrub or shrub plants. Geraniums originate from southern Africa and are widely cultivated around the world.
Geranium is a perennial evergreen herbaceous or subshrub flowering plant of the Geraniaceae family, genus Pelargonium. It originates from southern Africa and is widely cultivated around the world. Geraniums have a long flowering period and strong adaptability to the environment; their plant size suits household pot culture, and they are easy to propagate, making them very popular. They are one of the common potted flowers in homes and also a commonly used flower for flower beds in warm winter regions. Geranium flowers cluster together, and the large inflorescences resemble hydrangeas, with bright, vivid colors. They can be used for indoor decoration and also for arranging spring flower beds and venues. Below is a detailed introduction to how to grow geraniums:
1. Soil selection for growing geraniums
For potting geraniums, the growing medium can be a mix of 4 parts humus soil, 3 parts garden soil (or peat soil), 2 parts river sand (or perlite) and 1 part organic fertilizer; a mix of fine sandy soil, humus soil, perlite and organic fertilizer can also be used. Potted geraniums need repotting in autumn.
2. Fertilization methods for growing geraniums
During the growing period, apply liquid fertilizer once every 10 to 15 days, and in the vigorous growing seasons of spring and autumn, apply liquid fertilizer once every 7 to 10 days; before flower buds appear, nitrogen fertilizer should predominate, and after buds appear, phosphorus and potassium fertilizer should predominate, with a concentration of 0.1% to 0.2% being suitable. If the indoor temperature in winter is relatively high and growth has not stopped, fertilizer should also be applied. In the high-temperature period of summer the plant is in a semi-dormant state and fertilization should stop. Because its stems and leaves are covered with fine hairs, rinse with clean water immediately after fertilizing.
3. Watering methods for growing geraniums
Watering should be moderate, better dry than wet. In the peak growing seasons of spring and autumn, provide plenty of water to keep the potting soil consistently moist, but not waterlogged; on cold, overcast days, generally do not water and do not fertilize; in summer, water sparingly. In the north, the high-temperature season coincides with the rainy season; at this time the plant's root system is relatively weak, so avoid excessive rainwater irrigation; consecutive rainy days will cause root rot, so place the plant in a shady, high, dry and well-ventilated spot. In winter, water according to the indoor temperature; water less when the room temperature is low and more when it is high. Geraniums have a fairly strong drought tolerance and will not die of dryness if not watered for several days, but the old leaves will turn yellow and drop.
Water according to the principle of watering when dry and withholding when wet; overly wet potting soil easily causes root rot, while overly dry potting soil easily causes leaves to wither and yellow. From June to July the plant is in a semi-dormant state, and watering should be strictly controlled. In summer, spray water frequently to cool the plant and keep the potting soil moist, and also pay attention to ventilation and light. In winter, water sparingly.
4. Temperature requirements for growing geraniums
Geraniums like warmth, dislike high temperatures and fear cold. The suitable growing temperature for geraniums is 15 to 25°C, and indoors in winter a temperature of 10°C should be maintained. Below 3°C they are prone to cold damage, though some varieties can tolerate a low of 0°C. In summer, once the temperature exceeds 35°C, they enter a semi-dormant state.
5. Light requirements for growing geraniums
Under direct sunlight they grow robustly, with deep green leaves, short internodes and an attractive plant shape. But when summer light is too strong, 30% to 50% shade is needed. For home growing, place them in a spot with direct sunlight in autumn, winter and spring; when in bloom they can be moved indoors for enjoyment, but after flowering they should still be placed in a spot with light. They like ample sunlight; when light is insufficient they do not bloom; during the flowering period avoid direct strong light, otherwise the petals scorch and drop easily.
Turn the pot once a week so the leaf surface receives light evenly. Keep the plant shape symmetrical. In summer, place in a cool spot and avoid scorching sun. In winter, the room temperature should not be below 5°C, and give full light.
6. Pest and disease control for growing geraniums
The main diseases of geraniums include mosaic disease, crinkle disease, chlorosis, gray mold, root rot and bacterial wilt, and the main pests include whiteflies, caterpillars and small plume moths. To control mosaic disease, eliminating aphids is important, and other host plants nearby should also be cleared away; to control small plume moths, spray with a 1000-fold dilution of 90% trichlorfon.
7. Precautions for growing geraniums
(1) To control plant height and achieve large, vividly colored flowers, besides choosing dwarf geranium varieties, the application of growth regulators is very important. Two weeks after geraniums are planted in 12 cm or 15 cm pots, spray the leaves with 0.15% chlormequat or daminozide once a week for 2 consecutive times, with 14 to 18 hours of light per day; this can effectively control the height of geraniums and provide high-quality commercial potted flowers.
(2) It is fairly tolerant of dryness and afraid of waterlogging; too much water easily causes the plant to die, and under high temperature and high humidity the roots rot easily. It requires well-drained, loose soil rich in organic matter. The flowering period is long, with the peak bloom from April to June; if given a relatively high temperature in winter and managed properly, it can bloom continuously from September in autumn to June of the following year.
8. Propagation methods for growing geraniums
Geraniums are commonly propagated by seed and by cuttings, and can also be propagated by tissue culture.
(1) Seed propagation: single-petaled geranium varieties set seed easily, and the seeds can be sown as soon as collected. If you want to wait until the weather is cooler to sow, first dry the seeds and store them in a paper bag. At a temperature of 20°C, they germinate in about 7 to 10 days. After pricking out and transplanting, when the seedlings grow to 5 to 7 cm, plant them in 10 cm flower pots, and they can bloom the following spring.
Because plants grown from seed are poorer in both plant characteristics and flower quality, seed propagation is usually not used.
(2) Cutting propagation: cuttings can be taken at any time except from June to August, when the plant is in a semi-dormant state. Spring and autumn are best. Cuttings should preferably be taken from mother plants that flower consistently, flower frequently, are true to variety and free of pests and diseases; both the tender shoot tips and the tender stems below can serve as cuttings, but the tip portion is best, with strong growth vigor and fast rooting. After cutting the cuttings, soak them in 100 mg/kg indolebutyric acid for 5 to 10 seconds, then let them dry for half a day and allow them to wilt before inserting them in a sand bed or a medium of perlite and peat mixed 1:1; after watering thoroughly, cover with a small arched frame, and shade when sunlight is strong. Keep the temperature at 15 to 20°C; roots form 2 to 3 weeks after insertion, and when the roots are 3 to 4 cm long, transplant.
(3) Tissue culture propagation: use MS medium, adding 10 mg/kg indolebutyric acid and kinetin to promote callus and adventitious bud formation from the explant, and use 100 mg/kg indolebutyric acid or indoleacetic acid to promote rooting. Tissue culture propagation is mainly used for the propagation of superior varieties and the breeding of new varieties.
When is the best time to repot geraniums
Geraniums are easy to grow and have a long flowering period. The flowers are divided into single and double forms, and the flower colors include red, white, pink and purple; the leaf shape is attractive, and the large inflorescences resemble hydrangeas with bright, vivid colors, making them a fine variety for balcony flower growing.
Because they grow fast and bloom abundantly, they need repotting once a year. Early spring is the flowering season, and after flowering in June they enter the hot, humid season unsuitable for growth and are in a semi-dormant state. The best time for repotting is from late August to early September. Before repotting, prune to remove overly dense branches, slender branches, pest- and disease-damaged branches and leggy branches. Keep 3 to 5 evenly distributed main branches, then shorten both the main branches and the side branches, leaving only 3 side buds on each side branch, so that the branches of the whole plant are evenly distributed and compact, and the plant shape is full and stocky.
Use bone meal and the like as a base fertilizer, and water 2 days after planting. In November, move indoors to a sunny spot, and at the end of April move to the balcony, avoiding scorching sun. During growth and flowering, apply dilute liquid fertilizer once a week; in July and August stop fertilizing and water less. At ordinary times also control watering, and water only when the potting soil turns pale.
How to prevent geranium root rot
Geranium, also known as shilazihong, renlazihong, xiuqiuhua and yangxiuqiu, is a subshrub or perennial herbaceous plant of the Geraniaceae family, genus Pelargonium. The whole plant is covered with fine soft hairs and has a distinctive scent.
It originates from southern Africa and is now widely cultivated around the world. It likes a cool climate, with a suitable temperature of 10 to 25°C, can tolerate a low of 0°C, and enters a semi-dormant state during the high-temperature period in summer; it likes ample light, and when light is insufficient it does not bloom. During the flowering period avoid direct strong light, otherwise the petals scorch and drop easily; it tolerates dryness and dislikes waterlogging, and too much water carries a risk of death; it likes well-drained, loose soil. The peak bloom is from April to June, and the flowering period is long. If given a relatively high temperature in winter and managed properly, it can bloom continuously from October in autumn to June of the following year.
Spring and autumn are the vigorous growing periods for geraniums, when you can water a little more. When summer temperatures are high, geraniums enter a semi-dormant state, and watering must be strictly controlled. Just keep the potting soil from becoming too dry, and water in the morning and evening; never water at noon when the soil temperature is high, otherwise root rot is very likely. Keep the plant out of rain on rainy days, and during the "plum rain" season never let the potting soil stay overly wet for a long time.
To prevent geranium root rot, besides paying attention to watering, also choose sandy loam rich in humus and well drained and aerated. Heavy clay soil has poor structure, drainage and aeration, and cannot be used to plant geraniums.
When transplanting geraniums, the trowel should not be too close to the roots, to avoid damaging the root hairs. Keep the roots as intact as possible; if the roots are damaged, they most easily become moldy and rot after watering.
If you want geraniums not to suffer root rot, you also need to carry out timely pest and disease control. Nematodes are a common pest of geraniums; when the temperature is 25 to 30°C and the humidity is around 40%, it is the most suitable time for nematodes to invade geranium roots. When the damage is severe, root segments drop off one after another, and even the whole root system rots.
How to cultivate large-flowered geraniums?
Large-flowered geraniums like warmth, humidity and ample sunlight, fear waterlogging and frost, tolerate a certain degree of drought and also have some resistance to waterlogging, and are not particular about soil, but grow well in slightly acidic fertile soil. If the temperature is kept at 18 to 25°C and enough light is given, large-flowered geraniums can bloom all year round; if light or fertilizer is insufficient, the branches become leggy and flowering is sparse or absent. In home cultivation, from June to August in summer they enter a semi-dormant state due to the high temperature. For home growing in the north, in winter place them on a sunny indoor balcony and keep the temperature at 15 to 20°C; move them outdoors after the weather settles in April, and during the growing period keep spraying water on the leaves.
In daily management, create a suitable growing environment according to the habits of large-flowered geraniums. Although they are highly adaptable, to keep them flowering profusely and leafy all year round still requires meticulous management, and in particular note that daily light must not be less than 4 hours. First, always pay attention to ventilation and ensure humidity, and do a good job of cold protection in winter. Second, large-flowered geraniums grow very fast and their branches have a very strong phototropic tendency, so turn the flower pot once every 3 to 5 days to prevent an uneven crown, and at the same time pay attention to supplementing with compound fertilizer.
Third, the flower stems of large-flowered geraniums grow from the growing point at the top of the stem, so only by pruning more can the plant shape become full and symmetrical and the flowers be abundant, preventing leggy growth. Note that you must prevent them from dying of soft rot under conditions of sustained high temperature, high humidity and poor ventilation, and from cold damage when the temperature is below 2 to 3°C. The leaves of large-flowered geraniums can secrete antibiotics, and their ability to resist pests and diseases is extremely strong.
How can geraniums be grown well in summer and winter?
Geraniums have beautiful flowers and beautiful leaves; in particular, their leaves closely resemble a shield, which makes people feel curious, but some people find the smell of the leaves unpleasant. The characteristics of geraniums are many flowers and a long flowering period.
Two problems are quite prominent with geraniums. One is that flowers or leaves drop easily in summer; this is because they encounter heat and enter a semi-dormant state, so at this time watering should be controlled and fertilizing is even more inadvisable; move them to a cool spot and spray water around them to create a cool environment, and drain promptly after heavy rain to prevent waterlogging from causing root rot, which makes the leaves drop and turn yellow.
The other point is that for overwintering the temperature should be kept at around 12°C, and they should be placed in a sunny spot to overwinter. When the plant grows to 15 cm, pinch out the growing tip so that it produces more side branches and more flowers, and has a graceful plant shape.
Control methods for geranium leaf spot disease
[Symptoms] In the early stage of the disease, chlorotic spots appear on the infected leaves, and afterward the spots gradually enlarge to form relatively large circular lesions. The lesions are dark brown with concentric rings. In the late stage of the disease, a dark green mold layer appears on the lesions, which is the conidia of the pathogen.
[Occurrence pattern] The pathogen overwinters as mycelium in diseased plant residues or diseased tissues. When environmental conditions are suitable, it produces conidia. The conidia spread with wind and rain to cause infection and damage. During the growing season, the conidia can repeatedly infect the plant. The pathogen can invade directly through stomata, lenticels or the epidermis, forming a primary infection; after an incubation period of 2 to 3 days, lesions appear, and after 3 to 4 days conidia are produced, and multiple repeated infections occur through airflow and rainwater.
When geraniums enter the vigorous growing period and flowering period, the basal leaves begin to age and the pathogen accumulates on the plant; at this time, when there is continuous overcast rain and the relative humidity is greater than 70%, the disease begins to occur and spread. Therefore, how early the rainy season arrives, how many rainy days there are, and the amount and distribution of rainfall all affect the outbreak and spread of the disease.
[Control methods] 1. Reduce sources of infection. Promptly cut off diseased leaves when found and destroy them together with the diseased leaves; 2. Chemical control. In the early stage of the disease, spray a 1:1:200 Bordeaux mixture, or 50% thiram wettable powder, or a 600- to 800-fold dilution of 65% zineb wettable powder, once every 10 to 15 days, spraying 2 to 3 times.
Key tips for propagating geraniums by cuttings
Geraniums are mainly propagated by cuttings. Cuttings taken in April to May will bloom in autumn; cuttings taken in September to October will bloom in winter and spring. The stems are tender, juicy and hollow, and rot very easily after cutting; the thicker the stem, the higher the rot rate. Therefore, the following points should be noted when propagating by cuttings:
(1) Cutting time.
Geranium cuttings are usually taken in spring from April to May or in autumn in mid-to-late September, when the temperature is suitable. In summer, however, the temperature is high and the humidity is great, so the cuttings rot easily; in winter the temperature is low and rooting is slow.
(2) Cutting and handling of the cuttings.
When selecting cuttings, cut the growing tips of vigorous shoots and the tender stems below them from mother plants that flower consistently, flower freely, are true to variety and free of pests and diseases; the length is 7 to 10 cm. Do not insert the cuttings immediately after cutting; let them dry for at least a full day and night, and insert them only after the cut surface has dried. Alternatively, pinch out the growing tip of the mother plant intended for cuttings in advance; after new side shoots have grown, cut from the base of the new side shoots, close against the mother plant. Such cuttings have a small cut surface and are solid rather than hollow inside, readily form callus tissue, root quickly, rarely rot and have a high survival rate.
(3) Cutting and after-cutting management.
Clean river sand, vermiculite, perlite and the like can be used as the cutting medium. Insert to a depth of about 1/3 of the cutting's length, and cut off the large leaves on the cutting, leaving only 1/2 of a small leaf, to reduce water evaporation. After inserting, water thoroughly and first place in a cool spot away from direct sunlight; keep the medium temperature at 15°C, and roots will form in about 1 month. Once rooted, pot them up promptly.
Propagation methods for geraniums
(1) Seed propagation can be carried out in both spring and autumn, with indoor pot sowing in spring being preferable. The optimum germination temperature is 20 to 25°C. Geranium seeds are not large, so after sowing do not cover with soil too deeply; they germinate in about 14 to 21 days. Sown in autumn, they can bloom in the summer of the following year. From seedlings grown by seed propagation, superior intermediate-type varieties can be selected and bred.
(2) Cutting propagation can be carried out at any time except in June and July, when the plant is in a semi-dormant state. Spring and autumn are preferable. In summer's high temperatures, cuttings easily turn black and rot. The cuttings are 10 cm long, and the tip portion is best, with strong growth vigor and fast rooting. After cutting the cuttings, let the cut surface dry for several days, and after a thin film forms, insert them in a sand bed or a mixed medium of expanded perlite and peat; be careful not to damage the stem skin of the cuttings, otherwise the wound rots easily. After insertion, place in a semi-shady spot and keep the room temperature at 13 to 18°C; roots form 14 to 21 days after insertion, and when the roots are 3 to 4 cm long they can be potted. During the cutting process, soaking the base of the cuttings in 0.01% indolebutyric acid solution for 2 s can increase the survival rate and rooting rate of the cuttings. Generally, cutting-grown plants bloom 6 months after cultivation, that is, cuttings taken in January bloom in June; cuttings taken in October bloom in February to March of the following year.
(3) Tissue culture propagation Geraniums can also be propagated by tissue culture. Using MS medium as the basic medium, add 0.001% indoleacetic acid and kinetin to promote callus and adventitious bud formation from the explant, and use 0.01% indoleacetic acid to promote rooting.