Rosemary shrub is a plant that is very easy to take care of. It does not require a lot of water or sunlight to survive. This plant is very versatile and can be used in many different dishes. Rosemary shrub can also be used for decoration purposes.
Related plant:
Rosemary Tree
About soil condition, rosemary can grow in relatively poor soil, but will do best in loose, well-drained, somewhat sandy soil that is high in organic matter. The rosemary will also do well in a pot as long as it has good drainage.
Like the other herbs, rosemary requires full sun to grow properly. This means that it should be placed in an area of your yard that gets at least 6 hours of direct sunlight each day. If you live in an area with hot summers, it's best to grow rosemary in a spot that gets some afternoon shade to prevent the leaves from burning.
The temperature condition that is best for growing rosemary shrubs is one that is warm during the day and cool at night. Rosemary shrubs do not like extreme heat or cold and will not do well if the temperature fluctuates too much.
Ideal humidity condition for this plant is around 40%, anything lower than that will result in the leaves becoming dried out and falling off. The plant will also become more susceptible to pests and diseases. If the humidity is too high, the plant will start to produce excess moisture which can lead to fungal growth.
Discussing fertilizer, this family of plant nutrients is important for the growth and health of your rosemary shrub. Fertilizer provides plants with the necessary nutrients for proper growth and helps to replenish nutrients that may have been lost due to weather or other factors. When choosing a fertilizer for your rosemary shrub, be sure to select one that is specifically designed for shrubs. Using a fertilizer with too much nitrogen will encourage leaf growth at the expense of flower production.
Pruning a rosemary shrub is simple and easy to do. First, identify the woody, older stems near the base of the plant. These need to be pruned away to encourage new growth. Cut the stems at an angle just above a leaf node. Second, thin out the branches to create an open, airy shape. This will help the plant to produce more flowers. Finally, cut back any long, straggling stems to neaten up the plant.
Propagation is best done from semi-ripe cuttings taken in late summer or early autumn. Cuttings should be 10-15cm (4-6in) long and taken from the current season's growth. Remove the bottom leaves, dip the cuttings in hormone rooting powder and plant in a propagator or pot filled with moist, free-draining propagating compost. Cover with a plastic bag or propagator lid to maintain high humidity. Place in a light, warm position out of direct sunlight. Keep the compost moist but not waterlogged and after 8-10 weeks the cuttings should have rooted.Pot them up individually into 9cm (3½in) pots filled with moist, free-draining potting compost. Gradually acclimatise to outdoor conditions over 10-15 days before planting out in their final positions.
Usually, the plant growth rate is determined by the type of plant. Mediterranean rosemary grows quickly and can produce new leaves in as little as four weeks. However, some varieties of rosemary, such as those from the Atlantic Islands, have a growth rate that is much slower. No matter the type of rosemary, proper care is essential for encouraging growth. This includes ensuring the plant has adequate sunlight, water, and fertilizer.
Common problems for this kind of plant are scale insects and powdery mildew. Scale insects are small, hard-bodied creatures that feed on plant sap. They can be difficult to control because they often blend in with the plant's leaves or stems. Powdery mildew is a fungal disease that causes a white or gray powdery coating on the plant's leaves. It can be controlled with fungicides, but it is often difficult to eradicate completely.
Source:
Rosemary (Rosmarinus officinalis) UIC Heritage Garden
Rosemary: University of Illinois Extension
Managing Pests in Gardens: Herbs: Rosemary - ucanr.edu