Maintenance Landscaping Design

Mahonia is a plant that belongs to the barberry family. It is native to eastern Asia and North America. The plant is also known as Oregon grape, holly grape, and mountain grape. Mahonia plants are evergreen shrubs that can grow up to 6 meters tall. The leaves of the plant are pinnate and have 9-19 leaflets. The leaflets are 2-4 cm long and have sharp teeth on the edges. The flowers of the plant are yellow and are borne in clusters. The fruit of the plant is a black berry that is 1 cm in diameter.

Alternative name

• Oregon grape
  
• Mountain grape
  
• Tall Oregon grape
  
• Cascade Oregon grape
  
• Coastal Oregon grape

Things to Know

• Mahonia is a genus of approximately 70 species of evergreen shrubs and plants in the family Berberidaceae, native to temperate regions of the Northern Hemisphere.
  
• The species are known by the common names Oregon grape, holly grape, and mountain grape.
  
• The leaves of most mahonia species are pinnately compound, with 3-9 leaflets per leaf, and the leaves of some species (e.g. M. aquifolium) are serrated along the margins.
  
• The flowers of mahonia are small, yellow, and borne in clusters.
  
• The fruit of mahonia is a dark blue or black berry.
  
• Mahonia species are used as ornamental plants in gardens, and several species (e.g. M. aquifolium, M. japonica) are commercially grown for their berries, which are used in a variety of food and beverage products.
  
• Mahonia species are also used in traditional medicine, and extracts from the plants have shown antiviral, antibacterial, and antifungal activity in vitro.
  
• Some mahonia species (e.g. M. aquifolium, M. japonica) are considered invasive species in parts of the world.
  
• Mahonia is named after Philadelphia horticulturist Bernard McMahon (1775-1816).
  
• Mahonia is the state flower of Oregon, USA.

Related plant:
Mahonia Bealei

Growing Steps

1. For mahonia, first step is to find a location that has good drainage and is in full sun to part shade.
   
2. Next, dig a hole that is twice the width and depth of the plant’s root ball.
   
3. Amend the soil with compost or other organic matter if necessary to improve drainage.
   
4. Set the plant in the hole and backfill with soil, tamping it down gently as you go.
   
5. Water the plant deeply to settle the roots.
   
6. Apply a 2-3 inch layer of mulch around the plant, being sure to keep it away from the stem.
   
7. Mahonia is a slow grower, so be patient as it establishes.
   
8. Fertilize annually with a balanced fertilizer.
   
9. Prune as needed to shape the plant and remove any dead or damaged stems.
   
10. Watch for pests and diseases such as aphids and powdery mildew. Treat as needed.

The Soil

About soil condition,Mahonia tolerates a wide range of soil conditions, from sandy to clayey and from well-drained to moderately dry. It prefers slightly acidic to neutral soils with a pH of 6.0 to 7.5, but it can also tolerate alkaline soils with a pH of 8.0 to 8.5.

Light requirement

So, like the other plants, mahonia requires sunlight to grow. However, it can also tolerate partial shade. This means that it is a versatile plant that can be grown in a variety of locations. If you are planning on growing mahonia, be sure to give it plenty of space to spread out. It can reach up to 6 feet in height and width, so it will need room to grow.

Ideal Temperature

The temperature condition that is most favorable for the growth of Mahonia is a temperature that is cool to cold. The plant does not tolerate heat well, and will not grow well if the temperature gets too warm. The ideal temperature range for Mahonia is between 50 and 60 degrees Fahrenheit.

Humidity Level

Ideal humidity condition for this plant is between 40 to 60%. The plant cannot tolerate direct sunlight but needs bright, indirect light. Water the plant when the top soil is dry to touch. Allow the plant to dry out slightly between watering.

Fertilizing

For the fertilizer, this kind of plant prefers soil that is high in organic matter and nutrients. A good way to achieve this is to add plenty of compost or aged manure to the planting area before you add the Mahonia. As for the roots, they are relatively shallow so you'll want to make sure the soil is loose and not too compacted.

Light requirement

Pruning your Mahonia is best done in early spring. You can remove up to one-third of the plant's growth if needed. Mahonia can also be lightly pruned throughout the growing season to encourage bushier growth.

About Propagating

Propagation is best suited from semi-ripe cuttings taken from midsummer to early autumn. Cuttings should be taken from the current seasons growth and ideally be around 10-15cm in length. Use a sharp knife or secateurs to take your cuttings, and make sure to make a clean cut just below a node. Once you have your cutting, remove the bottom leaves and dip the cut end into some rooting hormone powder. Rooting hormone is not essential but will help to promote root growth.

Growth Speed

Usually, the plant growth rate during the spring and summer months. However, some varieties of mahonia can have a growth rate of up to 1 foot per week. This makes them ideal for use in hedges and as groundcover.

The Problems

Common problems for this kind of plant plants include powdery mildew, root rot, and leaf spot. These problems are often caused by too much water or too little light. If your mahonia plant is affected by any of these problems, you should try to correct the problem immediately.

Growing Tips

• Make sure to plant your mahonia in an area that gets full sun to partial shade.
  
• This plant does best in well-drained, humus-rich soil.
  
• Amend the planting area with compost or other organic matter before planting.
  
• Water your mahonia regularly, especially during the hot summer months.
  
• Fertilize your plant once a year with a balanced fertilizer.
  
• To encourage blooming, prune back the plant after it flowers.
  
• These plants can be subject to scale and aphid infestations. Check your plant regularly and treat accordingly.
  
• Mahonias are generally deer resistant.
  
• This plant can be propagated by dividing the clumps in spring or fall.
  
• The cultivar ‘Winter Sun’ is especially resistant to cold winters.

Similar Plants

• Mahonia aquifolium
  
• Mahonia bealei
  
• Mahonia japonica -- an ornamental evergreen shrub with glossy leaves and clusters of yellow flowers followed by purplish-black berries
  
• Mahonia lomariifolia
  
• Mahonia nevinii
  
• Mahonia pinnata
  
• Mahonia pinnatifolia
  
• Mahonia repens
  
• Mahonia richardsiae
  
• Mahonia subsessilis

Source:
Mahonia, Leatherleaf
Creeping Mahonia - Mahonia repens - PNW Plants
Oregon grape : Mahonia aquifolium - Berberidaceae (Barberry)