How to grow and care for roses (Rosa chinensis), plus points to note: when is the best time to take cuttings?

The rose is called the queen of flowers, also known as “monthly red”, and is an evergreen or semi-evergreen low shrub that blooms in all four seasons. Many friends are not particularly familiar with how to grow roses, and problems always arise during the growing process. So, what are the rose growing methods and points to note?

The rose belongs to the Rosaceae family. It can be used as an ornamental plant and also as a medicinal one. Rose flowers grow large, 4-5 cm in diameter, mostly double-petaled though some are single-petaled, with petals spreading from the inside outward. There are very many flower colors, with varied shades, and they are fragrant, widely used in horticultural cultivation and as cut flowers. Roses have a long flowering period and great ornamental value, and the rose is also used industrially to extract fragrance.

Rose growing methods and points to note

1. Choosing a flowerpot. When growing roses in pots, choosing a suitable pot is quite important.

First is the size of the pot. The pot size should match the size of the rose plant; avoid a small seedling in a large pot. When the plant's roots and stems have filled the pot, it should be repotted into a larger pot in good time to meet the growth needs of the roots and stems. Generally, a newly rooted cutting uses a 15 cm small pot, a 1-2 year old seedling uses an 18-20 cm pot, and afterward gradually move to larger pots.

Second is the choice of pot material. It is best to use breathable clay or tile pots; if using plastic pots, it is best to punch more holes in the bottom to increase air and water permeability.

2. Selecting and mixing potting soil.

For potted roses, since the potting soil is limited and roses are heavy-feeding flowers, the soil chosen should be as loose and breathable as possible, with good drainage, while also retaining water and nutrients. It is better to keep the soil pH slightly acidic or neutral.

Below are several commonly used potting soil recipes for roses:

Recipe 1: garden soil : compost : rice husk ash : rapeseed cake = 5:3:1:1

Recipe 2: garden soil : compost : river sand : rapeseed cake : bone meal = 3:3:2:1:1

Recipe 3: coco peat : perlite : vermiculite : rice husk charcoal = 5:1:1:1, plus a small amount of granular humic acid and Osmocote 318 fertilizer.

If you are growing relatively few roses, it is even better to simply buy special rose growing soil. Since special rose soil is fairly expensive, for growers with more roses it is still more economical to mix your own.

3. Light management for roses.

Roses like plenty of sunlight and should get no less than 5 hours of light per day, but strong direct sunlight should be avoided; when the midday sun is too strong in summer, some shading should be provided. When growing them on an indoor balcony, be sure to open doors and windows to keep the air circulating and avoid powdery mildew.

4. The effect of temperature on roses.

Roses are relatively cold-hardy. In winter, below 5 degrees they stop growing and enter a dormant state, and they can overwinter safely indoors. The most suitable temperature for roses is 18-20°C. When the temperature exceeds 25 degrees, the flowering period shortens; with high temperatures above 30 degrees and humid weather, the flowers are small and pale, and various pests and diseases easily occur, so in summer pay attention to cooling and ventilation. Under hot, dry conditions they will drop their leaves and go dormant.

5. How to water roses.

Roses should be watered so that conditions are neither too dry nor too wet, following the principle of “don't water until dry, and when you water, water thoroughly”. Soil that is too wet will cause root rot, yellowing leaves, and even death of the plant. So the watering frequency should be decided according to the water retention of the soil used in your own pots.

6. Fertilizer management for roses.

Roses bloom many times and have a large demand for fertilizer. Besides putting enough base fertilizer in the pot when planting, before they sprout in early spring you can use liquid fertilizers such as rotted soybean cake, manure water, chicken and duck manure, and fish innards. After buds appear, apply a dilute liquid fertilizer once every 10 days. In summer after the flowers fade, before the axillary buds develop, apply a medium-concentration rotted liquid fertilizer once to encourage abundant flowering in autumn.

When topdressing roses, follow the principle of “light fertilizer, applied frequently”; avoid raw fertilizer and concentrated fertilizer. Around December in winter, you can bury an appropriate amount of fish intestines along the edge of the pot, taking care that it does not directly touch the roots, and the following spring there will be even more flowers.

7. Prune branches and leaves in good time.

After roses finish flowering, promptly cut off the upper part of the branch connected to the spent flower, to encourage early new growth and more blooms. If there are particularly vigorous branches, they should be shortened appropriately to avoid consuming too many nutrients and affecting the growth of other branches.

When summer temperatures are too high, roses enter a semi-dormant state. At this time, prune the overly dense branches to increase ventilation and prevent disease.

8. Prevent pests and diseases in good time.

The main pests and diseases of roses include black spot, powdery mildew, leaf blight, June beetles, and slug moths. For pests and diseases, prevention should come first. In the rainy season of July-August and in hot, humid seasons, spray a fungicide once a week; during the winter dormant period, spray appropriately as conditions warrant.

Rose cuttings are one of the commonly used propagation methods. They not only preserve the good characteristics of fine rose varieties, but also have a high propagation rate, a short production cycle, low input, and quick results.

Rose cutting methods:

Cutting propagation can be divided into softwood cuttings, hardwood cuttings, full-sun cuttings, and bud cuttings.

① Softwood cuttings

These are done in April-May and September-October, the seasons of best growth, and rooting and survival are easiest at temperatures of 2-5°C. To promote rooting, dip the cut end in indolebutyric acid powder at a concentration of 500-750 ml. Choose vigorous flowering shoots of the current year as cuttings; after the flowers fade, remove the spent flowers and the dead leaves below them, and wait several days until the branch has regained nutrients, grown plump, and the leaf nodes have swollen. Then, in the morning, cut a branch about 10 cm long with 3-4 leaf nodes as the cutting, keeping only the upper two compound leaves; the remaining leaves are cut off together with their petioles, and of the two compound leaves kept, it is best to leave only the two small leaflets at the base, to reduce transpiration. The soil should be well drained and aerated; when preparing the beds, make the soil fine and soft, and space the cuttings so that they do not shade one another. The planting depth is 2/3 of the cutting, leaving 1-3 buds above ground. After inserting, water thoroughly and firm the cuttings into the soil. After insertion, shade them and cover with plastic film to retain moisture, uncovering at night for ventilation. Keep the soil moist but not too wet, so that the soil has enough air and the wounds do not rot. After about half a month, gradually increase the time in sunlight to boost photosynthesis and aid rooting. When new shoots grow and the old leaves do not drop, it means the cuttings have rooted and survived, and they can be transplanted.

② Hardwood cuttings

The soil and bed preparation are the same as for softwood cuttings. Cuttings can be taken from when roses drop their leaves and enter dormancy until they sprout the following spring. Basically any vigorous branch can serve as a cutting; cut a 10 cm branch with 3-4 leaf buds and leave no leaves. After inserting, water thoroughly, make arches with tree branches or other twigs or steel bars, and cover with plastic film. The propagation site should face the sun and be sheltered from wind to help retain moisture, and take care to prevent it drying out. When the cuttings sprout the following spring, remove the plastic film, and when the young leaves have grown and turned green and the lower roots have developed, they can be transplanted.

③ Bud cuttings

Because new shoots in spring have strong growth power, using them as cutting material gives a high survival rate. The method is: when the new shoot has grown to 3-7 cm, gently twist it off by hand, or use a blade to cut it from the base of the bud close against the branch. It is best to choose new shoots that are thick and strong, with plump buds, growing from the base of the main branch. After harvesting, wash them clean with water and they can be inserted. For the cutting soil, broken soil is best. When inserting, poke a hole with a stick slightly thinner than the bud, insert the bud along the hole to a depth of 1/3 of the bud's length, press it firmly against the soil, water thoroughly, and likewise cover with plastic film to prevent wind, but the humidity inside the cover should not be too high. Ventilate 1-2 times a day, keep the soil moist; after about half a month they can root, and after 20 days the plastic film can be removed and they can be transplanted with soil.

④ Full-sun cuttings

Full-sun cuttings means that throughout the entire cutting process no shading is used, so that the cuttings get ample sunlight. But because the cuttings have no root system they cannot take up water normally, making water uptake difficult. In order for the cuttings to carry out photosynthesis and life activities normally, water must be supplied through the leaf surface; frequently spraying the leaves forms a film of water on them, which both satisfies the water needs of the leaf cells and lowers leaf temperature, reducing transpiration, thus ensuring normal photosynthesis. If there is no sprayer, frequent spraying by hand can be used instead: in the first week after insertion, spray once every half hour, and after one week spray every 2 hours. Therefore the seedbed for full-sun cuttings should mainly be plain sand, and after 3 weeks they can be transplanted.

The effects and uses of roses

1. The rose is an ornamental flower with a long flowering period and fragrant, brightly colored blooms, and it has indispensable value in landscaping. It can be used in gardens for flower beds, flower borders, and courtyard floral material, can be made into rose bonsai, and used as cut flowers, flower baskets, bouquets, and so on. The rose is a major ornamental flower of spring, with a long flowering period, high ornamental value, and an affordable price, and it is quite popular with gardens everywhere. Roses can also be used to extract fragrance.

2. Roses have a unique role in garden streetscapes and beautifying the environment. They can be made into continuous flower hedges, flower screens, flower walls, and so on, used in government offices, schools, residential communities, urban squares, and other places; they not only purify the air and beautify the environment, but also greatly reduce noise pollution in surrounding areas and ease the greenhouse effect of the hot summer city.