General Outdoor Cultivation Problems
Causes and Remedies
Problem: Plants turn yellow at any time during all growth phases, less the final 2 weeks until harvest.
Cause: Lack of light or nutrition.
1. Outdoor container plants should be moved into full sun. Competing vegetation should be cleared out. If the weather has been miserable, hoping for a change is the only option.
Light levels must be extremely low for this to occur, because most plants will stay green and use less nutrients if grown in shady areas. Strain type is key.
2. Hopefully, the pH of soil or nutrient solution is proper.
For nutrition problems, plants should be fed with a balanced nutrient formulation as explained in this guide, or the medium should be flushed well. After the medium is cleaned, a grower should add a proper nutrient formulation.
This is the best way to deal with nutritional problems because it is very difficult to isolate one deficiency from another. Also, salts locked up in the soil may be inhibiting the plant from getting what it needs because nutrients are locked up, even when an ample supply of nutrients already exist in a growing medium such as soil / soilless mix.
Again, if the plants are fed properly, the pH is good, and the medium is not over-toxified, then a complete diet will be in the plants’ best interest.
The top leaves and new leaves should always be watched to see the color. The old leaves may not green up. Old leaves will reach a point of yellowness, and cannot turn around. Nitrogen is a common deficiency that first hits the older leaves. If the leaves are yellowing just slightly, then they should revive to a green color in less than a week.
Problem: Burning shoots.
Remedy: For overfertilization, a grower should flush each plant with several gallons of plain water immediately. The runoff (water that is flushed through medium) should be 0PPM. Feeding can be resumed a few days later.
Problem: Clones dry up and look near death.
Cause: Lid was not placed properly on the flat or it has holes in it, plants may not have been misted at regular intervals, or the heat pad thermostat may be malfunctioning. Or the rooting medium has dried up.
Remedy: Regular mistings and close attention and careful monitoring are necessary so that the rooting medium stays moist. If the clones are severely wilted new clones should be cut. Heat pad with high temperatures can dry out cloning mediums very quickly.
Problem: Germinated seedlings didn’t sprout through the mix, although everything was done as instructed in chapter 1.
Cause: Mice dug in mix and ate fresh shoots.
Remedy: The nursery room should be made so that mice cannot enter. Surrounding lights and plants with wood or plastic will prevent access.
Problem: Seedlings grew tall and spindly and are flopping over.
Cause: Light levels are not sufficient: fluorescents are too high above the plants or outside conditions were extremely poor. Enough gray and dark days and the plant will stretch for light, no matter how good the food supply is.
Remedy: The seedlings should be transplanted to larger pots and the stalks should be buried up to their first set of leaves. New roots will form from out of the stalks.
Problem: Fertilizer bags were broken into.
Cause: Rats like several types of organic fertilizers, such as canola meal and Flower Power.
Remedy: Fertilizers should be stored in a totally enclosed area.
Problem: Some plant leaves have many holes, with or without bugs present.
Cause: Bugs, or disease. Certain strains have these problems more than others.
Remedy: For bugs, Nitrozyme® (Growth Plustm) with organic insecticidal soap may be used as spelled out on pages 117 to 120. The right hours for foliar feeding are soon before or after the lights turn on indoors, or in the morning or early evening for outdoor plants.
Leaf spot fungus may show up in the outdoors whether or not the mix is contaminated. The inner parts of the leaves begin to rust, then the material falls out and leaves holes. A grower should get to the root of the problem by using 35% hydrogen peroxide (1 to 5ml per gallon) when watering, and using calcium peroxide (i.e. Soil blaster) or 35% hydrogen peroxide (2 to 5ml per gallon) before reusing soilless mix / soil. Leaf spot fungus problems are unpredictable. It will attack weak or healthy-looking plants. For example, in a 6 plant garden, one or more may have the disease, while the others will show no signs at all. This is not an epidemic.
Problem: Outdoor plants look abnormal in growth from others that are treated the same.
Cause: Predators such as slugs or deer. Or a frost could mutate the plants.
Remedy: The first step is to figure out what the predator is. Looking for the predator or a sign, such as slug slime, or deer footprints will determine the predator. Then it is recommended to use one of the control methods described on pages 117 to 122.
For a frost mutation, a grower should have a backup supply of plants because the mutated one may or may not grow or flower properly.
Problem: Outdoor plant fell over.
Cause: Too much mass combined with nature’s elements like wind and rain.
Remedy: Plants should be properly pruned and bent as discussed on pages 112 to 116.
Problem: Outdoor plants grew tall, but produced very few flowers.
Cause: Competing vegetation in the area blocked out sun to the lower parts of the plant and therefore only the top sections produced; lack of bloom food; too small a container size; or a poor strain for the area.
1. Pruning out surrounding vegetation with shears will allow a plant to receive full sun without blockage.
2. The right strain should always be used.
3. A proper fertilizing formula should be used, such as one of those described in chapter 3.
Problem: Outdoor flowers did not finish blooming, although good money was paid for an expensive mix.
Cause: Poor flowering conditions and/or wrong strain.
1. Using the right strain(s) with new fertilizers the next time is a step forward. Growing the right plants is half the battle. A plant’s ability to grow in a robust manner and produce the type of flower preferred is more genetic than a matter of technique. For example, a novice grower who grows small, underfertilized buds can produce buds of equal quality to a master gardener. A master can only do so much in terms of quality (not quantity) with a specific plant, no matter what.
2. Plants where no care is taken can acquire too many problems to list, but here are a few: Lack of water to a plant or overwatering a plant can stunt its growth.
Spraying an overdose of insecticide an put a plant on the path to non recovery. Transplanting a plant in the flowering state while mangling the roots can shut down performance levels. Overfertilizing a plant can retard growth performance.