ORNAMENTAL HORTICULTURE (2+1)

Management

Growing media
The potting soil, or media in which a plant grows, must be of good quality. It should be porous for root aeration and drainage, but also capable of water and nutrient retention. Most commercially prepared mixes contain no soil. High-quality artificial mixes generally contain slow-release fertilizers, which take care of a plant’s nutritional requirements for several months.
Most mixes contain a combination of organic matter, such as peat moss or ground pine bark, and an inorganic material, like washed sand, vermiculite, or perlite. Materials commonly used for indoor plants are the peat-lite mixtures, consisting of peat moss and either vermiculite or perlite.

Water management
The following are some important points to remember in water management of indoor plants.

Do’s

1. Use your soil probe to check the soil before watering.
2. Cover the soil surface evenly with water.
3. Be sure to water near the edges of the grow pot.
4. Pay attention to the light levels and air temperature that change with the seasons.

Don'ts:

1. Don't dump water in one spot; spread the water over the entire soil surface.
2. Don't allow plants to sit in saucers of water for more than 30 minutes. After the root ball absorbs enough water to sustain the plant discard the remaining water

Nutrient management
Houseplants grown in low light conditions of the interior environment have reduced fertilizer requirements. Usually in the spring and summer when sunlight intensities increase and the days are warmer and longer, fertilizers are applied. During the short days of winter, many houseplants that receive little or no artificial light enter a ‘resting stage’, during which no fertilizers are required to be applied.

Frequency of fertilizer application
Frequency of fertilizer application varies with the vigour of growth and age of each plant. As a rule, fertilizer application should be more frequent when the plants are growing.

Fertilizer type
A complete fertilizer (one that contains nitrogen, phosphorous and potassium) is an excellent choice for indoor gardens. Choose a balanced fertilizer such as 20-20-20 for foliage plants, and one that is higher in phosphorous such as 15-30-15 for flowering plants,
Fertilizers for houseplants are available in liquid form, water-soluble granules and slow-release forms (granules, sticks or tablets). Water-soluble fertilizers are often preferred because dilute solutions reduce the possibility of fertilizer burn.
Soils that have a white film on the surface or pots with a white crust on the rim or drainage hole may indicate that the plant is being over-fertilized and/or possibly over-watered. Salt buildup in the soil can lead to root damage, causing symptoms such as reduced growth, brown leaf tips, dropping of lower leaves and wilting of the plant. The most effective way to prevent salt injury is to prevent the salts from building up. This can be done by watering the soil thoroughly and allowing the excess to flow out of the drain holes into a tray.

General rules in nutrient management of indoor plants:

• Feed houseplants every two weeks during the summer months with a half strength fertilizer mix.
• Houseplants require little or no fertilizer during the winter months.
• Slow-growing plants need comparatively less fertilizers and rapidly growing plants will need comparatively more fertilizers.
• Flowering plants usually require both more light and more fertilizer than foliage plants.
• Properly prepared potting composts contain enough food for about two months.
• Never fertilize diseased and stressed plants.