Diagnosing the Issue

Too Much or Too Little Light

Providing proper light to your garden plants is critical to the success of your indoor garden. You will want to consider your light duration and light intensity. Make sure to follow the height recommendations for your lighting kit. Light should be on for at least 12 hours a day in your indoor garden, but ensure that plants receive a dark period too.

Overcrowding and Space Issues

Roots and foliage take up space. Each plant has their own specific space requirement needs. Plants that are spaced too close together will be stressed as they compete for their basic needs, resulting in weaker plants, higher susceptibility to diseases and insects, and ultimately poor food production. Plants also require air circulation.

Air Temperature and Humdity

Temperature is a factor that often goes unnoticed. We tend to assume that are plants are safe indoors; however, window sills can get cold at night or if temperatures drop in the evening. Low temperatures can cause defoliation, brown leaf tips, and yellowing leaves, so make sure you rule out this problem as you troubleshoot.

Nutrient Deficiencies

Plants must take up nutrients from the soil to support their health and growth. Because we use a sterilized, soil-less potting mix for indoor gardens, it is important that nutrients are added. Some potting mixes contain added nutrients, but if not, you will need to add compost or fertilizer to your garden. This is best added at the time of planting, though you may need to supplement nutrients again during the growing season. Plant roots also require certain conditions to obtain these nutrients from the soil. The most important of these is that the soil must be sufficiently moist to allow the roots to take up and transport the nutrients, but not waterlogged so as to prevent absorption.

Fungus Gnats

What they look like: Adult fungus gnats are small and black with thread-like antennae, long slender legs and clear wings. Fungus gnats look similar to fruit flies. Fungus gnats lay their eggs in moist soil where the larvae will hatch and feed on small roots, fungus and other organic matter in the soil. They have no interest in fruit. If you see tiny black bugs in plant soil, and flying around your plants – those are fungus gnats. The larvae can be clear or cream-colored with shiny black heads that look like small black specks to the naked eye and grow about a ¼-in. long.

Symptoms: The flying adults do not cause damage to the plant, but they lay eggs in the growing media and are a nuisance. The larvae do feed on the roots, making the plant weak and slow-growing, which can eventually lead to harm for your plants

Control: The most common way fungus gnats get into your garden is through soil of a purchased plant or the bag of potting soil you use. The first thing to do is to control soil moisture. Fungus gnats thrive in moist soil and can’t survive in dry soil. Apply insecticidal soap spray onto op your soil to kill gnats in potted plants. This is effective after a few applications. Lastly, you can replace the top inch of your soil with a fresh layer of potting soil, followed by a layer of sand. This will control the gnats in the soil and deter them from laying eggs.

Prevention: Do not reuse potting soil from year to year. Always use fresh, sterile potting mix when repotting plants. Use yellow sticky traps, which will attract and capture adult fungus gnats. This will not take care of the problem of fungus gnat larvae but it will be an early warning sign of a problem.

Mealy Bugs

Mealybugs are tiny white bugs on houseplants, and most commonly look like white fuzzy stuff on plants leaves and stems. Mealybugs can also appear brown or cream colored, and waxy in immature stages. At first glance they don’t look like insects, and are commonly mistaken for fungus or mildew rather than plant bugs. If the white bugs you see on your houseplants look more like tiny white flies that fly around when the plant is disturbed, then those are whiteflies instead of mealybugs. The first step is to quarantine your infected plant if you can.

Thrips

What they look like: Thrips are hard to see at a mere 5-mm long. They can be yellow, brown or black. To the naked eye, they look like tiny threads.

Symptoms: They leave fecal droppings on plants that appear as black spots. Females bore holes in leaves where they lay their eggs. If your garden is infested with thrips, leaves will eventually look dry—not wilted—and have yellowish spots. Look for silver or bronze colored streaks on leaves, which eventually turn brown, dry and crumbly. The pests feed by puncturing plants and sucking out the sap inside, creating the streaks.

Control: Remove any infected plants if you are able. Use an insecticidal soap spray made from water, dish-soap and vegetable oil (Directions on page ##).Repeat the treatment two to three times at 7- to 10-day intervals to ensure you’ve eliminated all of the pests and any new generations hatching.

Prevention: Check often for the presence of thrips by giving plants a gentle shake. The larva are wingless and will leap when jarred.

Spider Mites

What they look like: Spider mites, at less than 1-mm long, are tiny relatives of spiders with eight legs and oval bodies. Spider look like grains of sand and are found mostly on the undersides of leaves. Eggs are round and clear and become a creamy color just before hatching. If you see white webbing, you most likely have an infestation.

Symptoms: Spider mites mouthparts pierce and suck, causing damage by puncturing plant cells, resulting in fluid loss that eventually kills plants. An adult female can lay up to 20 eggs per day, causing infestations quickly.

Control: Isolate infested plants from others and spray them with a formula that kills the eggs and the larval stages as well as the adults. Use an insecticidal soap spray made from dish soap, water and vegetable oil. You will need to use two-three applications of soap spray. Once now, and once in 3 days and then 5-7 days to get the next generation.

Prevention: Spider mites often travel from garden to garden on nursery seedlings. Make sure to inspect any seedlings before planting in your garden.

Whiteflies

What they look like: Whiteflies resemble small, white moths and are about 1-mm long that cluster on the underside of leaves. The nymphs are translucent and can appear to be the same colour as the leaves. Like aphids, whiteflies secrete honeydew that is colonized by black sooty mold.

Symptoms: Look for stunted or twisted leaves, white spots or black moldy areas on the top of foliage.An adult’s mouth parts pierce and suck juices from plant leaves, causing white spots and yellowing. Females lay their eggs on the undersides of leaves. Another downside to whiteflies is that they secrete a sticky substance called honeydew, which is a breeding ground for sooty mold.

Control: Trim or remove infested and damaged plants or leaves. You can also try vacuuming whiteflies. This is a quick and straightforward control for whiteflies at all stages of growth. Be careful not to damage the plant. Simply use your handheld vacuum or vacuum cleaner’s hose attachment to suck up whiteflies every few days. Make sure that any newly hatched whiteflies can’t escape from your vacuum bag. Seal the bag when finished and leave in your freezer if available for 24 hour. You can also use an insecticidal soap spray made from dish soap, water and vegetable oil. Be sure to target the pests on the bottom of leaves, too. Ensure that you apply the spray every 3 days for 9 days to stop future generations.

Prevention: Whiteflies are drawn to the colour yellow, so set up yellow sticky traps. These will help capture whiteflies and help you monitor the pests. The traps alone can protect a few plants, but in larger indoor gardens they work best as an early warning system so you can notice an infestation before it spreads.

Fungal and Bacterial Leaf Spot

Symptoms: Infected plants have brown or black water-soaked spots on the foliage, sometimes with a yellow halo, usually uniform in size. The spots enlarge and will run together under wet conditions. Under dry conditions the spots have a speckled appearance. As spots become more numerous, entire leaves may yellow, wither and drop.

Causes: Leaf spot is a pathogen-caused fungal leaf spot. Leaf Spot is most active when there is plenty of moisture and warm temperatures.

Control: There is no cure for plants infected. You will want to discard any affected plant materials. Make sure to always disinfect your pruning equipment (one-part bleach to four-parts water) after each cut. Correct the water moisture levels and use an oscillating fan to promote air circulation. Prevention: Prune or stake plants to encourage air circulation or use an oscillating fan. Ensure moisture levels are not too high. Try not to water from above.

Prevention: We add lime to our Earthboxes, in part to add calcium to our potting soil to prevent blossom end rot. You will want to ensure moisture levels are kept even and that too much nitrogen fertilizer is not applied to the soil.

Grey Mold

Symptoms: Grey mold appears as brown patches that eventually become covered in grey or brown fuzzy mold. It is usually found on dead plant materials but may migrate to healthy plants. It is often found near the soil surface or in the densest areas of plant canopy.

Causes: Grey mold is a fungal disease called Botrytis that travels through a garden quickly in damp, cool conditions.

Control: Clean up dead plant debris. There is no control for affected plants, so dispose of all plant materials to prevent further spread.

Powdery Mildew

Symptoms: White to gray powdery coating, especially on young leaves. Blistered areas on leaf edges that causes them to curl upward.

Causes: Powdery mildew is caused by a fungus related to downy mildew called Cleistothecia.

What it does: Symptoms include stunted plant growth, leaf drop and chlorosis (the yellowing of plant tissues). Powdery mildew is a disease that shows up most prominently on new leaf growth.

Control: The fungi flourish in highly humid conditions and where there is little ventilation. The dampness of indoor gardens can be ideal for this fungus. Remove infected plants immediately from the garden. Ensure that there is enough room between plants for that moisture can evaporate. Use an oscillating fan for a few hours every day to create airflow and keep humidity in check.

Root Rot

Symptoms: Plant growth will become stunted, and then plants will wilt and turn yellow. The leaves start to get dull as the plant dies. You can remove the plant from the soil and feel the roots. Most often roots will look black and may fall from the plant when you touch them. Healthy roots may be black or pale but will feel firm and pliable.

Causes: Root rot is caused by too much water and/or soil-borne pathogens. Prolonged exposure to overwatered conditions can cause some of the roots to die back due to a lack of oxygen. The other cause is a fungus I the soil that will flare up after a few repeated situations of over watering.

Control: Ensure that your soil is not over-saturated and allow soil to dry. Your best bet is usually to discard the infected plant and soil and sterilize the growing containers. Some gardeners treat root rot by removing the plant from soil and washing roots under running water and cutting away affected roots. This is more common with established houseplants.

Verticillium

Symptoms: Plant leaves will begin to droop, turn yellow or brown, and begin to fall.

Causes: Verticillium wilt is a fungal disease of many garden plants including trees and shrubs but is most severe in the potato and tomato family. The fungus usually enters via roots, plugs the water moving tissues result in in sudden and permanent wilt in the plant. It damages leaves, stems and the fruit of the plant.

Control: Remove affected plant material immediately and dispose of your soil. You will want to sterilize your growing container before reuse. Prevention:Ensure that you are not re-using soil for similar crops. In our LGT garden you should use fresh soil each year! Make sure that soil is well drained. Ensure growing containers are sterilized each year before use.