How To Grow Plants In Water Without Using Soil : Best Plants To Grow In Water

Learn how to grow plants without using soil in water and a list of the best plants to grow in water including vegetables, herbs and houseplants that grow in water without soil, as I am doing in Sydney, Australia.
We all know that plants grow in soil. Soil provides nutrients to the roots needed for the growth of the plant. But can plants grow without soil? The answer is yes, soil is actually not necessary for plant growth. If the needed nutrients are provided without soil, say in water, the plant will grow well.

This method of growing plants in water without soil is known as hydroponics [1-2].

How To Grow Plants In Water

Different media such as coir peat, shredded paper, perlite, rice husk, vermiculite, pumice, sand gravel, wool, etc, can be used for growing plants instead of soil [3] to provide support for the plants root systems. The nutrients like nitrogen, phosphorus and potassium needed for the plant growth can be added into a plant's water supply to avoid the need of soil [4].

The advantage of growing plants in water by hydroponic solutions over traditional method is

Low maintenance
Disease resistant
Pest resistant
More efficient, High yield
Low water cost
Can be set up indoors

Many plants grow easily in water. However, it should be noted that rooting plant cuttings in water may be a slower method than soil-based planting. Some plant cuttings which take only 2-3 weeks in soil to root, may take 6-8 weeks in water. But as the water method is simple, many people prefer this method of rooting plant cuttings over traditional propagation methods.

Which Plants will Root in Water? Easy plants to propagate in Water

Many plant cuttings will root quite easily in water. You will find a list of vegetables, herbs and houseplants that can be grown in water.

Procedure For Growing Plants In Water in glass containers

Choice of Containers For Growing Plant Cuttings

1. You can use any type and shape of container that can hold water for rooting plants in water, but narrow-mouth containers are preferred. The mouth of the container should have enough size to insert cuttings and allow free movement of air inside needed for the roots.
2. The material of the container may be glass or plastic but avoide metals as they will corrode over time.
3. You can use colored bottles, jars, vase, even old globes (light bulbs), etc.
4. A dark colored or opaque container can prevent algae formation.
5. The containers should have a flat bottom so that they can be placed on any surface. Light globes can be hanged on walls.

Preparing Plant Cuttings For Propagation in Water

1. Softwood cuttings (newly growing stem) root quickly. Cut stems just below a bud (node, where a leaf attaches to the stem) using a clean and sharp knife.
2. Cuttings should be 4 to 6 inches long.
3. Cut off any rotten or dead leaves. Remove lower leaves from cuttings leaving the top two or three.
4. Remove any flowers on the cutting.
5. Insert in the water ensuring that some nodes are in the water. Do not put any leaves in the water.
6. Old wood (hardwood) cuttings from fruit trees, hibiscus, etc. will take longer to root.
7. You may put several cuttings in one container.
8. Roots will form in a few weeks, generally in 3-4 weeks but some plants will take longer.
9. When the roots are 1-2 inches long, the cuttings are ready to be potted.  Transfer the cuttings in pots. In a few weeks new growth will be starting, and soon you will have a new plant.
10. Many rooted cuttings can be left in water for longer time.

Water glass containers For plant propagation in  Water

Coleus

1. Use fresh water having without too much salt and /or bleaching chemical. Rain water, spring water and water from a well are ideal as they have some dissolved minerals that may benefits the plants.
2. Rainwater is best because it is naturally soft and free from chemicals like chlorine and fluoride and other chemicals found in tap water.
3. Tap water left overnight will remove the chlorine gas and can be used.
4. Once a week or whenever needed, throw out the water by tilting the container and add fresh water.
5. Fill water in the pot to 1/3 rd height.

Position

Place the container in a bright place out of direct sunlight. Once the roots start growing, usually between 2-6 weeks, water changes may not be necessary.

Names of Edible Best Plants That Grow In Water 

Following is the list of plants that grow in water and eaten as food like vegetables and herbs. How to grow edible flowers

Best Vegetables To Grow In Water

Growing vegetables in water is also easy.

Celery
Cucumbers (growing cucumbers in pots)
Lettuce (how to grow  lettuce)
Lotus
Peppers (how to grow chilles at home)
Spinach (growing spinach in containers)
Tomatoes (growing tomatoes in pots from seeds)
Water chestnut (how to peel chestnuts easily)
Watercress

Best Herbs To Grow In Water

Growing herbs from cuttings is quite easy, you can use the herb you get from the supermarket. The following herbs can be grown in water easily:

Basil
Coriander/Cilantro (growing cilantro in containers)
Lemon balm
Mint: Peppermint, Spearmint (growing mint in pots, How to grow mint from cuttings video )
Oregano
Rosemary
Sage
Stevia (how to grow stevia)
Tarragon
Thyme

Best Houseplants To Grow In Water

Many indoor houseplants such as begonia, coleus, impatiens, peace lilly and philodendrons root easily in water. Following is a list of best houseplants that can be rooted in water.

Straight Lucky Bamboo

African violet (Saintpaulia)
Aluminum plant
Arrowhead
Bamboo (Chinese lucky bamboo, Dracena, lucky bamboo care)
Begonia
Chinese evergreen (Aglaonemas)
Christmas Cactus (Zygocactus)
Coleus (coleus plant care)
Cordyline terminalis (Ti Plant)
Crotons (growing crotons in water)
Creeping Fig (Ficus pumila)
Dumb cane (Dieffenbachia)
English Ivy (Hedera), Swedish Ivy (Plectranthus), Grape Ivy (Cissus)
Geranium (Pelargonium)
Hibiscus (Hibiscus propagation)
Hyacinth
Impatiens
Peace lily (Peace lily plant care youtube)
Philodendron oxycardium (Heart Leaf)
Philodendron pandureaform (Fiddle Leaf)
Pothos (Scindapsus, money plant, growing pothos in water)
Roses (how to grow roses in water)
Spider plant (Chlorophytum)
Syngonia (Tri-Leaf Wonder)
Tradescantia (Wandering Jew) 

Arrowhead Plant, Chinese Evergreen, English Ivy, Heartleaf Philodendron, Pothos etc.
are better grown in water beads as their toots will rot in water.

Water-Grown Plants

It is pointed that the above list of plants that grow in water are only for rooting the stem cuttings and not kept permanently in water. However, there are some plants that are grown in water only [5]. These water plants can be planted in ponds or other water features.
Following is a partial list of plants that grow in water only:

Amazon Lily
Arrowhead
Duckweed
Fairy Moss
Lotus
Marsh Marigold
Sorrel
Water Clover
Water Hyacinth
Water Lily

Video on Best houseplants to propagate in water

References

1. Petrus Langenhoven, Hydroponics, January 5, 2016
J. D. Santos, et al., Development of a vinasse nutritive solutions for hydroponics, Journal of 2. Environmental Management. 114: 8–12 (2013)
3. Hydroponics
4. Opportunities in Hydroponics, pdf
5. Water Plants