Learn what your plants will need to grow happily indoors

Water

Water is a vital part to the health of indoor plants. The vertical garden systems are designed to allow the correct amounts of vital air and water supply, but it is still possible to overwater your plants so it is important to note their specific water needs.  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 all the time.  A good rule of thumb with these plants is to water carefully each time the surface becomes dry, but never frequently enough to keep the compost permanently 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 (unless you are using supplemental light).  Let the top ½ inch of the soil dry out between each time watering.  This is especially important between autumn and mid spring.

4) Dry in Winter plants. Unless you are using supplemental light to support the growth of your plants, you should note that plants need a rest in the winter months when the natural light is not sufficient 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.

Danger Signs

 Signs of too little 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 moldy
• Young and old leaves die at the same time
• Roots brown and turn mushy
• Leaves curl, turn yellow and wilt
• Leaf tips brown

BEST WATER TO USE 

Because tap water carriers minerals which can leave deposits on the surface of the plants soil as well as the vertical garden structures, it is recommended that all of your indoor plants be watered with distilled water at room temperature.  

WHEN TO WATER 

The best way to discover when your plants need water is to look at the surface of the soil. Check daily in the summer months. If you live in a hot climate you should check daily during the spring months as well. Check weekly in the winter. If the surface looks dry and powdery all over, and the plant is in the wet or moist at all times category, water the plant. If it is not in those categories, do the finger test. Put your finger in the soil to the depth of your fingernail. If you fingertip remains dry, water your plant. There are exceptions to this rule, however. Cacti and succulents, during the winter months, should not be watered even if your fingertip remains dry. Unless there are signs of shriveling in these plants, it is best to leave them alone in the winter months.

HOW TO WATER 

This may seem obvious, but there is actually some technique involved in watering. Use a watering can with a long, this spout. Insert the end of the spout under the leaves and pour the water steadily and gently. Never water in full sun as splashed leaves may be scorched. 

Some plants, like African Violet, Gloxinia, and Cyclamen do not like water on their leaves or crowns, so they need to be watered from below (if possible).  

HOW OFTEN TO WATER 

How often to water can vary, sometimes greatly, depending on the environment and on the specific plant. Fleshy-leaved plants, like succulents, can tolerate much drier conditions than thin-leaved plants. Rooted cuttings will take up less water than mature plants. A good rule of thumb is, the larger the surface of the leaf, and the more rapidly it is growing, the greater will be its need for frequent watering. In the winter, growth slows down and could stop in some varieties. Therefore, you should decrease the frequency of watering. Until the plant growth resumes, you should limit your watering to one to three times a month, depending on how the plant responds. During the spring and summer, watering may be necessary on a daily basis (depending on the type of plant and the structure it is growing in). As the temperature and light intensity increases, so does the need for water.

Food 

The three most discussed nutrients for plants are Nitrogen (N), Phosphate (P), and Potassium (K).

Most fertilizers describe their nutrient content in the ratio of nitrogen to phosphate to potassium.  This is often read as simply three numbers, which tell you the percentage of that nutrient, on the package.  For example, Dr. Earth Organic Tomato, Vegetable and Herb Fertilizer is 5-7-3, meaning that this particular 4 pound box is comprised of 5% nitrogen, 7% phosphate, and 3% potassium.  It is important to note, however, that these guidelines are really just the tip of the iceberg when it comes to plant nutrition. Just like with the food that people eat, we know the main categories of nutrients, but there are many, many other factors that play a role in how well the food nourishes the person (or plant).

You may have heard the term "whole foods".  The principle of whole foods is based on the belief that nutrients that come in their most basic and natural forms (like from raw vegetables) are more complete and more nutritious than manufactured nutrients (like in vitamin capsules or powdered nutrients).  Organic fertilizers take this same approach in that they provide the nutrient and the source of the nutrient in the most whole form possible.  That is why you will see organic fertilizers containing fish bone meal, kelp meal, rock phosphate, and seaweed.  These fertilizers contain the nitrogen, phosphate, and potassium, but they also contain the trace elements which are so important to the health of the plant.

The plants grown in vertical garden systems are heavily dependent on the nutrient content of their water because they live in such little soil.  Therefore, it is very important to provide a good organic, water-soluble fertilizer.  Synthetic fertilizers often contain amounts of nutrients that are not natural or healthy for plants, forcing them to grow at rates which are unsustainable.  You are often left with plants which are dependent on this unnatural nutrient level for the remainder of their lives.

Nitrogen 

It is important to know what the three main nutrients are responsible for in plant development so that you can recognize deficiencies when present and know the proper solutions. Nitrogen deficiency is probably the most common nutritional problem affecting plants worldwide. It is an important component of many important structural, genetic, and metabolic compounds in plant cells. Without going into chemistry, it is fair to say that 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 because it lacks the ingredient to manufacture adequate structural and genetic materials.It is usually pale green or yellowish, because it lacks adequate chlorophyll. Older leaves often become necrotic and die as the plant moves nitrogen from less important older tissues to more important younger ones. Plants given too much nitrogen develop protoplasm faster than they can build sufficient supporting material in cell walls. These plants are often weak and prone to mechanical injury.Nitrogen is often referred to as the leaf maker.  

Phosphorus 

Phosphorus, like nitrogen is an essential part of the process of photosynthesis, helping with the transformation of solar energy into chemical energy. 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 

Potassium helps in the building of protein, photosynthesis, fruit quality and reduction of diseases. Because of this, potassium is called the flower maker.

Environment

Most plants need humid air in order to thrive. This is because they have tiny pores on their leaves, through which they breathe. These pores dry out when the surrounding air is dry. This is a loss which the plant cannot always replace through the water absorbed by the roots.  Generally, the thinner the leaf is, the greater its need for humidity. Thick, leathery, or waxy leaves (such as cacti and succulents) are immune to dry air, which is why they do so well in the desert where the air is extremely dry. If you live in a temperate climate, you may not need to worry about humidity until you start using your central heater in the winter. Heaters make the air temperature more comfortable, but they also dry it out. If you live in a climate where you need to use your heater often, you should pay close attention to the relative humidity in the air.

You have some different options for increasing the humidity of the plant's microclimate.  

1. Keep your plants in humid parts of your home, like the kitchen, bathroom, or a terrarium.
2. Use a humidifier to increase the moisture content of the whole room or house.
3. Use a mister to deposit a coating of small droplets over the leaves.  If you do this, it is best to use tepid water and under cool conditions.  The morning is a good time for this job 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.
4. Double potting can increase the humidity in the microclimate of your plant.  Use an outer waterproof container and fill the space between the pot and the container with moist peat moss or coco coir.  Keep this packing material thoroughly and continually moist so that there will always be a surface layer of moisture to evaporate and raise the humidity.
5. Grouping your plants together, like is done in vertical gardens, increases the moisture arising from damp soil and the foliage of the surrounding plants.  The air trapped between the plants will have an appreciably higher relative humidity than the atmosphere around the plants.  It is important to note that grouping plants too close together can result in Botrytis or Grey Mold.  All soft-leaved plants can be affected - Begonia, Cyclamen, Gloxinia and Saintpaulia are particularly susceptible.  If this happens to your plants, cut away and remove the affected parts. Remove any moldy soil if present.  Reduce watering and misting and increase air circulation.  Sometimes a small fan pointed in the direction of the fan on a low setting does the trick. Because the plants are grouped tightly in vertical gardening it is important to watch for signs of too much humidity and to prune your plants when appropriate or to use plants which grow slowly.

Signs of too little 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 mold on leaves
• Patches of rot on leaves or stems
• Flowers covered with grey mold

Rest

This is an aspect of indoor plant care that is often overlooked.  Plants need a dormant or resting period during the year when the days become shorter and the light supply decreases.  This is unless you supplement the plants with artificial growing lights.  Not all plants will remind you that they need rest.  Bulbous and tuberous plants (Hyacinth, Cyclamen, and Gloxinia) will die down their top growth.  Deciduous woody plants (Pomigranate, Pionsettia) will drop their leaves.  Evergreen house plants will give little or no indication that they need rest.  However, as the duration of natural light gets shorter and shorter as winter approaches, the plant cannot support the same growth without light supplementation.    It is essential to reduce the frequency of watering and feeding during this time. Some plants will also require cooler conditions at this time.

There are some exceptions to this rule, of course.  Winter-flowering pot plants, like Winter Cherry and Eranthis, must be fed and watered regularly for as long as they are on display indoors.  The other large exception is when you supplement plants with enough artificial light to compensate for the loss of natural light.  Keep in mind that artificial lighting does alter the microclimate, so humidity and moisture should be monitored.

Light

Click here for the Grow Light Decision Making Guide to decide if you need grow lights

When growing plants indoors, good, consistent light can be hard to come by. Natural sunlight coming through a window is not as strong as sunlight outside, and the intensity of the light drops rapidly the further the plant is moved from the window supplying the light. The light intensity from windows is also relative to the orientation of the building and the window.

In North America, Europe, and much of Asia, South facing windows provide the most light because the sun follows a slightly southern east-to-west arc across the sky. Plants placed in unblocked southern windows will receive the most light.

North facing windows tend to have the weakest light intensity. In the summer months, when the sun is out the longest, north facing windows should be able to support the needs of shade-loving plants, but in the winter, even these plants will need supplemental light to survive.

Because the sun rises in the East, East facing windows benefit most from the morning sun. These are natural places for plants that need moderate sunlight or morning sunlight only. In hot climates, some plants will wilt if exposed to afternoon sun, even filtered through a window. If this is true for your plants, East facing windows are a good choice.

Due to the same principle, West facing windows get the full afternoon and evening sun, which can be surprisingly strong in the summer. The intensity of light is not as strong as southern exposures, however, a west-facing window will support sun-loving plants.

There are many ways to measure light intensity. In Jon VanZile's artical called Plant Lighting - Understanding Natural Light for Houseplants, he explains several tips for the indoor gardener. For example, the amount of shadow cast by the light can be used as a guide for measuring light intensity. A sharp, well-defined shadow implies bright light, while a fuzzy, indeterminate shadow is moderate light. No shadow at all is heading for lower light intensity.

Many growers also use foot-candles as a measurement for quantifying light intensity. One foot-candle is the light intensity of a single candle. To make it easier to discuss the lighting requirements of plants and the ways to meet those lighting requirements, these pages will convert foot-candles to wattage, as wattage is a common measurement used for the intensity of supplemental grow light bulbs. To convert foot-candles to wattage you can use this formula:

Wattage = # of foot-candles x 10.75 x .001496

ESTIMATING THE NATURAL LIGHT IN YOUR AREA

Direct Sun - within 2 ft. of a south-facing window - provides 24 watts

Some Direct Sun - a brightly lit area, with some sunlight falling on the leaves during the day, west or east facing window sills or more than 2 feet awayfrom a south facing window sill - provides 15 watts

Bright But Not Direct  - an area close to but not in the zone lit by direct sunlight, area extending about 5 ft. around the window sill which is sunlit for part of the day - provides 10-15 watts depeding on the exact placement.    

Semi-Shaded - moderately lit area within 5 to 8 ft. of a sunlit window or close to a sunless window - provides 5 - 10 watts

Shade - 20 ft. from a south window, 10 ft. from a east or west window, or 3 ft. from a north window - provides 2 - 5 watts

Signs of Too Little Light: 

• Leaves smaller and paler than normal
• Blooms absent in flowering types
• Lower leaves turn yellow, then dry up and fall
• No growth at all, or spindly growth with abnormally long spaces between leaves
• Variegated leaves turn all-green

Signs on Too Much Light:

• Brown or grey scorch patches
• Leaves have "washed-out appearance"
• Leaves of 'sun shy' varieties shriveled and dead
• Leaves wilt at midday  

TIPS FOR USING LED GROW LIGHTS  INDOORS

Click here for the Grow Light Decision Making Guide to decide if you need grow lights

Grow lights must use it properly for optimum growth and yield. The biggest mistakes people make with LEDs are not having enough light and not placing the light at the proper distance. Placing a light too close will stunt growth, too far will cause stretching.

Keeping the proper distance between your LED grow lights and your plants is important to robust photosynthesis and growth.  Your LED grow light provides the wavelengths of light your plants need for growth and flowering. The general rule of thumb is to increase the distance between the top of the plants’ canopy and the light source as the light becomes more intense. This means that hydroponic LED grow lights of different power ratings will perform best at different distances. A smaller, less intense light like the 120 Watt LED Grow Light can be lowered to 18-24 inches from the top of the canopy. The 240 Watt LED Grow Light should be 24-30 inches from the top of the canopy. Larger lights such as the 450 Watt LED Grow Light should be lowered around 30-36 inches from the top of the canopy. More intense lights such as the 600 & 900 Watt LED Grow Light should be kept 36-42 inches from the top of the canopy of your plants.

Since LEDs do not emit great amount of heat like MH/HPS systems, you can better regulate the room temperature and the temperature immediately below your light. Ambient room temperature can be 82 degrees instead of 72 degrees during lighting and can go as low as 60-65 degrees when the lights are out.

Vegetative Stage

During the vegetative stage is when you will start to reap the benefits of your LED grow lights. During this period you will save on your electricity bills and get superior growing results if you properly follow the general tips listed in this section. In the vegetative stage, plants need less intense lighting than in the flowering stage.

Vegetative growth is maintained with 16 or more hours of light. You can even keep the plants under 24 hours of light and they will continue to grow in this stage. However, the recommended growth cycle is 18 hours of light during the vegetative growth stage. This light cycle will create an environment that mimics the photo period in the summer with long days.

Turn your LED grow light ON for 18 hours a day and then turn the light OFF and leave your plant in the dark for another 6 hours. Your plant will need four to six weeks of this cycle to be ready to start the flowering stage.

Flowering Stage

Pre-flowers are the first indication that the plant is ready to move into the next stage of growth. The pre-flowers grow at branch inter-nodes just behindthe leaf spur in around the fourth week of vegetative growth, when the plant is six to eight weeks old. When you start seeing pre-flowers forming this means that the plants are ready to go into the flowering stage. You can continue to grow in the vegetative growth stage or switch to flowering at this point. The pre-flower looks like a regular female flower with white fuzzy pistils. The pre-flowering can take from one to two weeks. Wait to induce flowering until pre-flowers have appeared. Induce flowering by switching your light cycle to 12 hours of uninterrupted darkness and 12 hours of light.
Flowering

With LED grow lights we mimic the seasons by changing the light cycle from 18 hours a day to 12 hours. Give your plants 12 hours of uninterrupted darkness and 12 hours of light to induce visible signs of flowering in two weeks or less.  Adding more light to the plants also help give bigger flowers and yield. It is recommended to add an all red 90 watt led grow light at this stage for more robust flowering.

Once you have induced flowering for one to two weeks and flowering starts, it can last can last eight weeks or longer. During flowering growth patterns and chemistry changes in the plants (i.e. indoor growing flowering stages). Stems elongate, leaves grow progressively fewer blades and flower formation is rapid at first then slows. Phosphorus and potassium uptake increase to promote floral formation. Your nutrients should have less nitrogen and more potassium and phosphorus during flowering.  Don’t give nutrients too often as this can cause your plant to get nutrient burned. You should use about 30% less nutrients with LED flowering grow lights as compared to MH/HPS systems. Do not over water and do not harvest too early.