1. Container Gardening Part 4 Problem Diagnosis
This is first of 4 parts of the soils and fertilizers lectures. In this first part, we will learn about soil strcture.

2. Container Plant Problems
Overwatering
Improper watering and salt build up
Low humidity
Insufficient light
Exposure to drafts
Exposure to direct heat
Pest problems
Root bound
Of all of the problems that may plague a container plant – overwatering is probably the most common. Overwatering can result in root rot. Unfortunately, the above ground symptoms of root rot are wilting – which many rookie gardeners mistakenly interpret as ‘this plant needs more water’. Thus, they perpetuate the problem by watering more.
Improper watering – where the soil goes from saturated to dry, and then back to saturated and then back to dry, can result in salt build up on your plants and in the soil. Of course, this will impact the osmotic balance of the soil – such that water will be pulled out of the plant roots – to try and equilibrate the salts in the soil.
Low humidity, insufficient light, exposure to drafts and exposure to direct heat are problems that most plague indoor houseplants.
Pest problems don’t tend to be as big an issue on houseplants or container plants – in part because of the sterile media in which container plants are often grown. However, fungal pathogens, insects and even vertebrates can infect or feed on container plants. Monitor your plants for potential problems, and treat with a least toxic method – such as a cultural or physical control – at the earliest sign of a problem.
Root boundedness, behind overwatering, is probably the next most common problem that plagues container grown plants. As plants begin to grow, their roots will abut up against the container walls, and begin to circle. If severe enough, this will kill the plant.
Root pruning can help with this problem. For more information, refer to the ‘External Links’ associated with this module. There, you will find a video on root pruning.

3. Common Problems in Container Gardening
Symptom
Problem
Solution
Plants yellowing from bottom. Lack vigor. Poor color
Excessive water. Low fertility.
Reduce watering intervals. Increase fertility of feeding solutions.
Plants wilt, although sufficient water it present.
Poor drainage and aeration.
Use mixes containing higher percentage of organic matter. Increase number of drainage holes.
Marginal burning of leaves.
High salts.
Leach container with tap water.
Plants stunted in growth. Sickly, purplish color.
Low temperature. Low phosphate.
Relocate container to warmer area. Increase phosphate in feeding solutions.
Holes in leaves. Leaves distorted in shape.
Insects, slugs
Handpick or wash insects off of plant. Use EPA-labeled insecticide.
Plants with spots, dried areas, or powdery, rusty areas.
Plant disease agents.
Remove and properly dispose of diseased areas. Use EPA-labeled fungicide.
Here is a list of common problems associated with container grown plants. Of course, the best solution to a problem with a container grown plant – and for all plants, for that matter – is to use good horticultural technique so that you prevent as many problems as possible. Prevention is almost always less painful than remediation.

4. Edema / Guttation Edema on Philodendron Guttation
Edema causes swellings on leaves of susceptible plants such as geraniums and philodendron. It is caused by high humidity and overwatering - where the result is that cells absorb more water than can transpire.
To control this disease, you can increase light levels, so that plants increase their rate of photosynthesis – or you can increase air circulation to reduce humidity – or you can allow the plant to dry out before watering. Once the plant is dry, water it well.
Don’t allow water to sit in the saucer, and check the drainage hole to make sure that it’s not plugged.
Guttation is also a watering problem - droplets of sticky moisture appear on uninjured leaves as a result of too much soil moisture and too much humidity in the air. Moisture is not lost as quickly through evaporation in very humid air as is being absorbed by the roots, so it oozes out of plant pores. It is often seen as a sugary-looking crystal at the base of a leaf of a weeping fig. Sometimes, guttation is mistaken as insect damage. To control guttation, use the same techniques described for control of edema.

5. Temperature Issues Too hot – double pot or use large pots
Too cold – insulate or use large pots
There are a couple of things you can do if you are having issues with hot temperatures, cold temperatures, or temperature fluctuations. If your soils are too hot, you can use the pot in pot method – to provide insulation to your plants’ root system. If your soils are too cold, you can wrap an insulating fabric around your pots Or even use the pot in pot method to provide insulation. But, perhaps the easiest thing to do is use a large container. Large containers hold a larger volume of soil – which will lend some measure of protection to plants against temperature extremes or fluctuations.