Foliage plants grow best where the humidity is high. The humidity in Alberta is very low. The grouping of a number of plants and the use of “pebble trays” can be beneficial to increase humidity. The ideal relative humidity should be maintained about 40 to 50%.
Watering and Fertilizing
Most foliage plants are adapted to regions where the soil is moist but not continually saturated with water. Plants also require air in contact with their roots. Apply enough water to thoroughly wet the entire soil ball during each watering. The interval between waterings will depend upon the variety of the plant, size of pot, amount of light, temperature and humidity.
Roots should not be allowed to stand in water for any length of time.
Calgary water is alkaline with a pH of 7.8 to 8.2. One tea bag to a gallon of city water will be approximately 6.0 on the pH scale. Let stand at room temperature.
The pH of: Cacti 7.8
Tropicals 6.0 to 7.0
Acid Plants 5.5
(Norfolk pine, azalea, citrus, camellia, gardenia, hibiscus)
Many types of attractive containers are available. Containers without drainage holes should be avoided. Plants grown in clay pots must be watered more frequently than those in plastic or ceramic because of moisture evaporation through the porous pot.
Foliage plants can be grown in a variety of soil mixes, but are easier to care for if planted in soils containing high levels of peat moss. Such soils retain water and fertilizer and provide good aeration if peat moss is mixed with coarse sandy soils or perlite.
Plants may be cleaned by misting with tepid water or wiping with a soft cloth. Warm (not hot) tea water is excellent for cleaning stubborn spots and shining leaves. Don't fold, crease or rub leaves too hard, as they may be damaged.
General Fertilizing Tips
All plants, indoors or out, need an adequate nutrient supply. Nitrogen, phosphates and potash together with small amounts of trace elements are required to enable your plants to produce full sized flowers and leaves.
In the garden you usually apply fertilizers to top up the soil’s natural resources, but even in their absence the plant can send out new roots to draw on the soil’s nutrient supply. Indoors this is quite different. The soil or compost in a pot contains a limited amount of food; this is continually depleted by the roots of the plant and by leaching through the drainage holes. Once the nutrient supply is exhausted regular feeding when the plant is actively growing is necessary. Vigorous foliage and flowering plants are seriously affected if not fed.
Some signs which could indicate that your plants need repotting are:
- decreasing leaf size on new growth
- roots appear on soil surface
- lower leaves turn yellow
- plant wilts rapidly after watering
- soil dries out quickly
Spring or early summer is the prime times for repotting. Never repot a sick plant. After repotting, water thoroughly with Plant Prod Starter, 10-52-10 and use as directed (new pot should be about 2” wider and deeper). Soil washing or leaching should be done regularly to prevent buildup of fertilizer and toxic salts. After leaching, take a sharp pencil and make holes down through the soil to aid soil in drying.
Common House Plant Problems and Their Solutions
Sudden Leaf Drop
Caused by shock - typically incurred by exposure to extreme changes in air temperature or drafts.
Solution: Ensure plant is situated in an area away from drafts, vents and heat registers. Avoid severe fluctuations in room temperature. Plant may or may not recover depending on severity of shock.
Browning On Tips or Edges of Leaves
This symptom is usually indicative of dry air, although over watering or damage from sprays may also be a factor.
Solution: See section on humidity.
Flower Buds Drop
Usually caused by over watering or drastic fluctuations in the wet - dry cycle. Insufficient light may also be a factor.
Solution: Ensure that plant attains the requisite state of dryness in between each watering (this will depend upon the plant species) and that plant does not suffer from erratic watering i.e.: going from being waterlogged to being too dry.
Gradual Leaf Drop
The lower leaves of the plant begin to shed one by one - the leaves may be discoloured and shriveled in appearance. The most probable cause of this is over watering.
Solution: See section on flower buds drop.
Small, black, winged insects appear on soil and leaves of plants - insects fly around when plant is disturbed.
Solution: Fungus gnats thrive in moist soil: therefore allowing the plant a longer interval for drying in between each watering may be helpful. In conjunction with adjusting the frequency of each watering, the use of strategically placed Sticky Stix or Sticky Strips is highly effective. Sticky Stix and Sticky Strips are yellow coloured traps with an adhesive surface. The yellow colour is an attractant for the fungus gnats, and the adhesive surface ensnares them after contact with the trap is made.
Minute, soft- bodied insects are visible. They may be green, orange, black or grey. The plant may be covered with a shiny, sticky substance.
Solution: If possible, try to wash plant down with room temperature water, gently extricating as many aphids as possible. Afterwards spray plant thoroughly (just before the point of runoff) with either insecticidal soap or a spray containing pyrethrins (such as End All).
Webbing may be noticed around plant leaves and stems. When a sheet of paper is held under a stem, and the stem is tapped sharply, minute red or yellow specks will appear on the paper and crawl around. Leaves may be stippled or “dirty” in appearance.
Solution: If possible, try to wash down plant with room temperature water, extricating as much of the webbing as possible. While the plant is wet, spray it down thoroughly with insecticidal soap, subsequent applications as per label instructions may be required. If the infestation is heavy, the plant may need to be cut back extensively prior to soap application.
NOTE: Consult the label of any pest control product you are considering purchasing to make sure it is safe for indoor use, and compatible with your plant.