Water is a vital part to healthy indoor plants. Plants can be grouped into four categories when it comes to their watering needs.
1. Wet At All Times
Very few plants belong in this group. Examples are Acorus, Azalea, and Cyperus. These plants want their soil to be wet, not merely moist.
2. Moist At All Times
Most flowering plants belong in this group. They want moist, but not wet soil at all times. A good rule with keeping these plants happy is to water carefully each time the surface becomes dry, but not too much so that the compost permanently stays saturated.
3. Moist/Dry plants
Most foliage house plants belong in this group. Water these plants thoroughly and frequently between spring and autumn, and sparingly in winter. Let the top ½ inch of the soil dry out between each watering. This is especially important between autumn and mid spring.
4. Dry in Winter plants
Plants need a rest in the winter months when there is not enough natural light to support their spring-time growth habits. Desert Cacti and Succulents are in this category, but only during their down time (winter). During the active growing season (from spring to autumn) they should be treated as if they were in the Moist/Dry category. In the winter, these plants should be allowed to dry out almost completely.
Signs of not enough water
- Leaves are limp and wilted.
- There is little or no growth.
- Lower leaves are curled, yellow and wilted.
- Leaf edges are brown and dry.
- Flowers fall or quickly fade.
- The oldest leaves fall first.
Signs of too much water
- Leaves are limp and soft with rotten areas.
- Growth is poor.
- Flowers are mouldy.
- Young and old leaves die at the same time.
- Roots brown and turn mushy.
- Leaves curl, turn yellow and wilt.
- Leaf tips browned as if they were in the Moist/Dry category. In the winter, these plants should be allowed to dry out almost completely.
The three most discussed nutrients for indoor plants are Nitrogen (N), Phosphate (P), and Potassium (K).
Nitrogen allows a plant to grow rapidly and to produce large amounts of succulent, green foliage. A nitrogen deficient plant is generally small and develops slowly. It is usually pale green or yellowish, because it lacks adequate chlorophyll. Older leaves often die as the plant moves nitrogen from less important older tissues to more important younger ones.
Plants given too much nitrogen develop protoplasm and are often weak and prone to injury.
Nitrogen is often referred to as the leaf maker.
Phosphorus, like nitrogen is an important part of the process of photosynthesis. Phosphorus allows for proper plant maturation, encouraging blooming and root growth. It often comes in the form of bone meal in organic fertilizers.
Phosphorus is commonly called the root maker.
Potassium helps in the building of protein, photosynthesis, fruit quality and reduction of diseases.
Because of this, potassium is called the flower maker.
Best Recommended Indoor Mix and Plant Food:
Outdoor use - Tui All Purpose Potting Mix
Indoor use – Yates Professional Mix and Ican Fast Food
Pests & Diseases
Most indoor plant pests and diseases can be controlled using Grosafe Freeflo Copper.
Most indoor plants need humid air in order to thrive. This is because they have tiny pores on their leaves from which they breathe.
These pores dry out when the surrounding air is dry. This is where in New Zealand, because of our temperate climate, the use of heaters will dry out the environment much faster and the indoor garden needs attention through the colder months.
To help with this, keep plants in humid parts of the home, like the kitchen, bathroom, or in a terrarium.
The use of a spray bottle to create a coating of small droplets over leaves will help plants. If you do this, it's best to use tepid water in the morning so that the foliage will be dry before nightfall. It is important to cover the whole plant, not just one side. Other benefits of misting are that it has a cooling effect on hot sunny days, it discourages spider mites, and it reduces the dust deposit on leaves.
Signs of not enough humidity
- Leaf tips turn brown and shrivel
- Leaf edges turn yellow
- Leaf wilting may occur
- Buds and flowers shrivel and fall
- Leaves fall if plant is very sensitive to dry air
Signs of too much humidity
- Patches of grey mould on leaves
- Patches of rot on leaves or stems
- Flowers covered with grey mould
Our Best Indoor Plants
Palms and Cycads
Sansevieria (mother in-laws tongue)
Growing an Indoor Herb Garden
Many herbs, including oregano, thyme, rosemary and sage are best propagated for indoor growing by taking a cutting from an existing outdoor plant.
To do it, snip off a 4-inch section, measured back from the tip. Strip off the lower leaves and stick the stem into a moist, soil less mix, such as perlite and/or vermiculite. To ensure good humidity, cover with glass or clear plastic, and keep the growing medium-moist.
Before the first autumn frost (while the weather is still on the mild side), move them into a bright, cool "transitional zone," such as a garage, entryway, or enclosed porch, for a few weeks.
Once they've acclimated, move them to an area with lots of sun (north-facing windows are brightest, followed by west views). But protect them from heat and dryness.
Most herbs like to be well watered but don't like wet feet. That's why drainage is important. Water when the top of the soil feels dry, or learn to judge the moisture in the soil by the weight of the pot. Add sand or vermiculite to the potting soil to ensure good drainage.
Learn to juggle water, light, and temperature. A herb in a clay pot in a north-facing window will need more water than one in a plastic pot. If the light is low, keep the temperature low.