Maintaining a Mother Plant: A Guide to Best Practices & Common Issues

Many gardeners have both a burning desire and a genuine need to preserve their prized plants. Some growers want to share their best plants with friends; others want to ensure they will be able to continue to grow those genetically gifted plants for years to come; and still others need to ensure they will have superior genetic materials to use in their breeding programs.

Regardless of the reasons why you want to preserve your plants’ particular genetics, you have a few options. One option is to try to keep plants alive for countless years. Keeping plants alive is harder than it sounds; you can run into insect infestations, pathogen attacks or just natural senescence (the deterioration of cells from the aging process).

Some perennial plants have evolved to live for extended periods of time, but trying to keep an annual plant alive for many years is like trying to keep a human being alive for centuries.

A second option is using tissue culture to keep plants alive for extended periods of time without the risk of attack by insects or diseases (when done correctly), although this process requires expensive equipment, a lot of time and some training.

A third option, and one of the most common methods of vegetative propagation used in horticulture, is cloning, or the taking of cuttings. During this process, a mother plant—the plant whose genes you want to preserve—has small branches removed. The cuttings are treated with a mixture of hormones via cloning gels or powders to promote root growth and then they are planted in a suitable growing media, where they take root and become genetic copies of the mother plant.

Mother plants are raised solely to provide cuttings. Since cuttings take time to develop roots, the clones must use stored carbohydrates and water to provide the nutrition necessary to grow a new root system. Consequently, the health of the mother plant is critical in ensuring the most healthy and vigorous clones. The following tips will help you provide top-of-the-line mother plant care for amazing clones.

Read also: Cannabis Cloning 101: A Back-to-basics Guide

Cuttings and clones being grown indoors in a marijuana grow tent. Source: mikeledray/Shutterstock

Customize the Feeding Schedule of a Mother Plant

To ensure your mother plant provides vigorous cuttings, you must customize the fertilization schedule. Many growers feed mother plants a standard vegetative fertilizer, which is not ideal for a donor plant.

Mother plants should be on a nutrient program that minimizes the use of nitrogen, especially nitrates. This will increase the carbon-to-nitrogen ratio, allowing for greater storage of carbohydrates and a healthier rooted cutting. If a mother plant is fed excessive nitrogen, then it will grow quickly, but the growths will be soft and leggy with little carbohydrates, leading to cuttings with soft stems and a greater susceptibility to diseases.

Choose a fertilizer with a 1:1 ratio of nitrogen to potassium, as unnecessary potassium tends to exacerbate the problems associated with nitrate imbalances. It is better to feed a mother plant minimal nitrate nitrogen, and then if you notice a general yellowing of the leaves, feed the plant a little nitrogen boost fertilizer.

Another essential element in a mother plant’s fertilizer regimen is calcium. The calcium in your fertilizer is moved through the plant via the xylem from the roots to the leaves and stems, where it helps produce thicker stems and stronger cell walls. More robust cell walls and thicker stems translate to stronger clones with less disease susceptibility.

Other beneficial additives for mother plants include amino acids, humic and fulvic acids, and bio-stimulants like kelp or seaweed extracts. Amino acids can open absorption pathways in roots, allowing for increased absorption of elements such as calcium, which can increase absorption a thousand fold.

Humic acid, when combined with kelp extracts in a 5:2 ratio and applied to a mother plant’s root system, helps plants produce the antioxidant superoxide dismutase (SOD), which in turn helps protect plant cell membranes from heat and drought stress. This additional heat and drought stress can make a significant difference in the survival rates of tender cuttings.

Foliar feeding mother plants a mixture of fulvic acid and seaweed 2-3 times per week for a couple of weeks prior to taking cuttings also makes for stronger clones. The fulvic acid acts as a chelation agent, transporting metal ions across cell membranes inside of plant cells, where they are most needed, and stimulates enzymes, increasing the rate of chemical reactions within plant cells.

When foliar feeding plants, remember to add a wetting agent or surfactant to your foliar mixture for better absorption into plants. It is a small price to pay for increased efficacy!

Read More: Humic and Fulvic Acids: What Kind Are Your Plants On?

Keep Track of a Mother Plant's Age

Many of the plants gardeners grow are annuals—plants that complete their life cycles, from germination to the production of seed, within one year. Keeping annuals as mother plants for extended periods of time can result in less robust cuttings that are more susceptible to diseases.

As plants grow, they keep track of their cellular age with an internal clock based on their circadian rhythms. As plant cells age, they naturally become less efficient as their proteins and DNA break down. The breakdown of proteins and DNA is a slow process with little impacts early on, but the older the cells get, the greater the cumulative effect this degradation has. Eventually, it decreases the likelihood that an organism, especially a clone, will survive.

While a mother plant may make an excellent donor for the first year or two, eventually it will experience enough cellular degradation that the survival rate of the cuttings will be greatly decreased. To this end, keeping track of the age of your mother plant and your cloning success rate will give you a good idea of when and if it is time to choose a new mother.

Remember that a clone of a mother has the same genetic age as the original mother and regenerating a mother from a clone will likely result in the same issues that the donor plant originally had.

To maintain a mother plant for extended periods of time, fertilize properly, keep track of her age and always keep back-up genetics around, because nothing lasts forever!

Read next: The Easiest way to Clone a Cannabis Plant and Grow Mother Plants