Failure to Thrive

The plants you see on TV and in magazines always look perfect, but real life is seldom like that. Plants rarely have perfectly rounded shapes or masses of fruit and flowers wherever you look. In real life, plants often have one side that looks and performs better. Things are uneven. Movie star plants (and their human counterparts) look the way they do because they are frequently airbrushed and staged by professionals.


Imperfections are perfectly normal in the plant (and human) world. Failing to thrive is something else altogether.

Improper conditions can really mess with your harvest (Kate Russell)

Failure to thrive is not a disease. It is a symptom. And most of us have seen it happen in our gardens or patios. Scraggly stems, too few leaves, little or no fruit or flowers, and overall weakness are all signs of failing to thrive. You can help your plant return to good health once you know the cause. Failure to thrive is usually an environmental or biological issue.


Biological causes of failure to thrive

Some plants are born weak. It can be because the seed was old, or germination occurred too early in the season while temperatures were too cold. In both cases, the seedling had to put out more energy than it could afford, too early in its growth, and may never recover fully. Other biological causes of failure to thrive include diseases and improper planting.

Being rootbound makes growing difficult (Kate Russell)

You can prevent many problems with these tips:

• Use certified pest- and disease-free seeds and seedlings.
• Quarantine new plants.
• Plant seeds at the proper depth.
• Wait for temperatures to be warm enough.
• Inspect root systems of bare root trees before planting for signs of roots that may girdle the young tree.
• Resist the urge to tamp down the soil when planting seeds and seedlings. Instead, mud them in with water.
• Install plants with an eye to their mature size.
• Send a soil sample to a lab for testing and only add what is needed and nothing more.
• Avoid overhead watering or water early in the day.
• Prune plants for good airflow.
• Keep your pruning tools sharp and sanitize them regularly.

Environmental causes behind a failure to thrive

Plants cannot leave their environment, so they deal with wherever they are. Several environmental conditions keep plants from thriving:

• Plants installed in an unsuitable microclimate or USDA Hardiness Zone rarely thrive.
• The wrong size container can choke a root system. A root bound plant rarely grows well.
• Too much or too little water is a common environmental problem, easily corrected with an inexpensive moisture meter. Trees and shrubs, especially, need a lot of water when establishing a root system.
• Too much competition from nearby plants can make life hard for more timid, slow-growing plants. At the same time, plants rarely grow in isolation. Find a good balance between the two extremes.
• The wrong timing, intensity, or duration of sun exposure can cause plants to falter.
• Sap-sucking insects, such as aphids, mealybugs, and whiteflies, can starve plants into poor growth. Sticky sheets are an inexpensive control measure.
• Poor plant nutrition in the form of too much, too little, or nutrient imbalances can wreak havoc on plant health. Only a lab-based soil test can give you the information you need to know if your plants are getting what they need. Luckily, those tests are affordable.
• Mechanical damage from weedwackers, mowers, children, pets, birds, mice, rats, squirrels, and the rest can damage a plant to the point of no return.

Black aphids on bolting spinach (Kate Russell)

Pea plant infected with Fusarium wilt (Kate Russell)

Drastic measures

In some cases, you have to take more drastic measures. After all your other treatments and corrections have failed, it is time to dig up or unpot your plants and get to the root of the problem. You will want to work over a tarp or a large container. Either dig up your problem plant or remove it from its container. Shake the soil from the roots and wash them. Root washing is an excellent way to see what is going on underground. Prune out any damaged, mushy, broken, or infected roots. Set the root ball in a bucket of water and examine the soil. Look for signs of insect pupae, grubs, root maggots, root weevils, wireworms, cutworms, and other soil-dwelling pests.


Smell the soil. Does it smell rich and earthy? Or does it smell funky, like old gym socks? Healthy soil contains earthworms and zillions of microorganisms. And it smells like good earth. Less-than-ideal soil smells like something rotten. If that’s the case, toss it in the trash and give your patient some fresh potting soil. Until your plant is thriving, if possible, keep it in a container in a protected location during its recovery.