If your leaves of your container plants develop dry, brown tips, you probably are witnessing leaf scorch or tip burn. There are a few causes of this problem, so you must determine the cause of the leaf scorch before attempting to fix the problem in your garden.
Too Much or Too Little Watering. Leaf scorch is a sign that your container plant is not able to take in enough water to suit its needs. The leaf tips are the first part of the container plant to die because it is the part of the plant that is farthest away from the roots, where water intake occurs.
It’s common sense to look at a plant with dry leaf tips and think that it isn’t being provided with enough water, but it could actually be getting too much water. When a plant’s roots are left soggy, which often happens in container gardens, the plant is unable to grow new roots and take in enough water.
Watering problems are common in container gardening. Plant containers either hold too much water (plastic containers with improper drainage), or the potting soil dries out easily because moisture evaporates from porous plant container materials (i.e. terra cotta plant containers).
Air Is Too Hot or Too Dry. Another problem could be heat or dry air. Heat causes a plant to shut down, and it won’t take in moisture. If the air is too dry, moisture may evaporate from the plant’s leaves and cause it to scorch.
Too Much Light. If you put a shade-loving plant in a sunny location, this can also cause leaf scorch. With container gardens, this problem is easy to fix. Just move the plant to a shadier location. If you don’t have a naturally shady spot in your balcony garden, keep the plant inside, place a taller plant in front of it, or use a curtain or umbrella to provide more shade.
Too Much Fertilizer. Fertilizers, because they are saltier than the container plants, can also cause root damage and burn the plants. Refrain from fertilizing during hot summer months when potting soil tends to dry out in balcony gardens. Also make sure to not provide your plant with too much fertilizer.
What to Do. Once you see scorched leaves or tips on your container garden's plants, the first thing you should do is move the container plant to a less sunny location. Check online or in a book to see what light and watering requirements the plant needs. If you have been watering too much, make sure the plant has adequate drainage (if not, consider repotting) and correct the conditions for the plant. If you have been watering the right amount and have given it enough (but not too much) sun, hot and dry weather is the most likely cause of plant leaf scorch. Temporarily keep it in a shadier spot, and water more often if the potting soil gets too dry. If you notice your garden's soil drying out quickly, add mulch or stones on top of any exposed soil. This will help insulate the potting soil and help it hold moisture.
If a plant in your container garden gets scorched leaf tips, don’t worry. If you pay attention to your plants and see the damage early, you can most likely help your container plant to recover completely. But if a plant has completely shut down and has damage beyond repair, you may not be able to save it.