The importance of root maintenance to a healthy root system cannot be overstated. All successful growth begins with a well-developed and flourishing root mass. Roots play a crucial role in a plant’s physiology performing key functions such as absorption of water, minerals and other soluble and gaseous compounds. Roots also act to stabilize and anchor the plants and assist in keeping them upright while bearing any weight of fruits and flowers; this is especially important when growing high yielding, fruiting and flowering crops. Regardless of the growing method, it’s important to have a well thought out plan for root maintenance, and upkeep of the plant’s root mass.
Healthy roots are the hallmark of any well maintained and dialed in hydroponics system. Positive signs to look for when reviewing your plant’s root zone include healthy root tips, generally white in color, turgid (firm, hydrated) roots, free of debris and discoloration. Healthy roots are generally populated with both fine and course roots throughout the structure. This diverse array of roots serves varying functions that are essential to a plant’s life.
If plants begin to show signs of stress it may be helpful to take a closer look at the plant’s root zone to assess general health. If having issue, roots will appear flaccid, brownish in color and can exhibit signs of a slimy substance if roots have begun to break down and become colonized with bacteria. Plants will often display signs of stress through yellowing leaves, purpling petioles and poorly developed new growth. These issues can arise at any point during the growing cycle if the water chemistry or environmental conditions are out of balance.
Remember, the best solution to a problem is avoiding it in the first place. Avoiding issue can be accomplished by having good general practices and carrying out preventative root maintenance. If not properly maintained, issues can arise such as addressed in the following paragraphs.
Root Diseases and Pests
Root diseases and pests can be found in all growing applications. From hydroponics to soil, it is important that the growing environment is kept clean to prevent any setbacks to healthy plant growth.
Pythium is a name given to several species of fungal organisms that are the main culprits of root rot. Spreading easily from outside factors, Pythium can exist in all grow media and develop at any time during the lifecycle of a plant. Under the right conditions such as poor aeration, insufficient drainage and extreme root zone temperatures, Pythium can thrive and overtake the growing environment.
Vegetative: Some of the first signs of root rot are stunted growth and wilted leaves that may be brown or yellow in color. Infected plants will take on a droopy appearance and lack the overall vigor associated with thriving plants. Often the plant will seem to recover during its night cycle only to die off soon after. Unless treated root rot will persist and continue to spread.
Root: Below the surface look for root tissue that is brown, dead and easily pulled off. Infected roots will be lacking the vascular structure seen in healthy growth. Roots become soft, stubby and will lack feeder roots.
Once established Pythium can be difficult to control, but if caught early and combined with a fast, effective treatment it can be maintained. Cleaning and sanitizing all equipment between growth cycles should be a regular practice. This can be done with chemical agents such as a diluted bleach solution or other effective treatments.
Like stated above the best method to control Pythium is regular root maintenance, such as regular flushing of the root zone. This can be done with chemical or biological treatments. Flushing’s can be done weekly, but the key here is consistency. Maintain records of any treatment and root maintenance for future reference.
Root aphids are small, flat, oval pests that make a living at or slightly above the soil line. They’re from family Phemphigus, which include many of the common winged aphids known to gardeners. About the size of a pin head, they can be found with or without wings, either type will not fly. They come in several colors, such as green, white and brown. Their size, color and appearance make them difficult to spot, often times it’s the damage they’ve caused that makes their presence known.
Much like their winged cousins that feed on sap from stems and leaves, root aphids feed on the sap from plant roots. Instead of the ‘honeydew’ produced by their winged counterparts, root aphids will produce a white, waxy substance that is the hallmark of an infestation. In small numbers, root aphid damage is hard to spot; but as their numbers increase, plants will begin to show signs of infestation.
Look for wilted, loose leaves, stunted growth, and off-colored foliage. These symptoms mimic other plant diseases and nutrient deficiencies, which again makes their presence difficult to diagnose. In addition, root aphid feeding spots will leave that area, and ultimately the plant susceptible to root rot and other diseases. If left untreated root aphids will continue to produce and eventually sap the health and vigor of a plant which could result in reduced yields or death.
Just like other forms of treatment mentioned above, the best way to avoid root aphids is preventative care. The most common way of root aphid transmission is introducing equipment, contaminated soil or newly acquired plants into your grow area. Pretreatment of these sources is key to prevent any transmission. Be sure to only purchase from reliable, clean sources.
If infestation has already set in, treatment depends on method of growing. Consult your local grow shop for pest control options.
Root Maintenance and Treatment
Use UC Roots in the following measurement and applications.
- Root Maintenance: add 1-5ml of UC Roots per gallon every 5-7 days with water temperature under 70 degrees. If over 70 degrees, replenish every 3-5 days.
- Flushing: add 10ml per gallon for no more than 24 hours.
- Cleaning Equipment: add 30ml of UC Roots per gallon and let this solution. circulate for 24 hours. Drain and refill.
- Cloner: use 5ml per gallon and repeat this step every 3-5 days. For use as a clone dip, use 30-60ml per gallon.
The use of beneficial bacteria to curtail the spread of dangerous pathogens is another way to promote healthy roots. Plants have developed complex relationships with beneficial microbes over time and the introduction of these microbes can be of great benefit to the promotion of a healthy root system. This must be done with care; it is not recommended to use non-approved beneficial bacteria in DWC/RDWC systems. One product that DWC/RDWC growers can turn to is Mycostop. Mycostop contains the naturally occurring bacteria Streptomyces griseoviridis, and can be used as a biological defense against root infecting fungi that cause wilt and root rot. This active bacterium stimulates root hormones that will in turn increase the plants natural resistance too harmful bacterial and fungi.
Just like with any treatment the best way to use Mycostop is preventively. Apply monthly at regular intervals. Streptomyces survives in the root zone for several weeks protecting the surrounding root zone from harmful pathogens. In addition, Mycostop has been shown to improve overall plant vigor and increase yields.
In addition to other forms of promoting root health, one important element to keeping a functional and maintained root system is root pruning. In systems such as DWC/RDWC roots can proliferate to an extent that they may impede the flow of circulation. Root pruning is the process of severing outer roots to promote new growth and maintaining proper root structure. Root pruning also promotes lateral root growth which will contribute to a healthy root structure. A single root when pruned will split into multiple feeder roots, resulting in increased root surface area. This dense root mass will allow for optimum nutrient and oxygen uptake.
Examine the root structure and look for uneven growth. Any tool used in this process must be sterilized to avoid infecting the plant with pathogens. Use the sterilized pair of scissors to prune any “runner” roots to maintain a compact and uniform root mass. This pruning will promote lateral root growth and contribute to the plants ability to uptake available nutrients. With this technique less is more and should only be done as needed with no more than 15-20% of the root mass pruned at any one time. It is also important to only prune the outermost root mass to ensure optimum root health. Root pruning should cease once in bloom cycle. Any disturbance such as root pruning can shock a plant and leave little time to recover.
These root maintenance procedures and techniques can help any grower curtail many root issues they may encounter. It is imperative for fruiting and flowering plants to get off to a healthy start if they are to perform to their full potential. Paying close attention to root structure and health is the best way to achieve this. Root health is a complex subject, one with many differentiating opinions. It can be difficult to sift through the vast amounts of information to find those techniques that work for your garden. But combined with routine root maintenance, the mentioned techniques can help any garden reach its maximum potential.