One of the most common problems with houseplants is the dreaded brown tips that often appear on plant leaves. This malady happens not only to homeowners, but commercial growers as well, creating an unsightly "blemish" on the leaves of plants.
Often times it's hard to pinpoint the cause exactly, but following some of common sense practices may help to lessen the frequency or stop it from happening all together.
1. Maintain humidity
Dry air is one of the biggest culprits for tip burn in houseplants. As most houseplants are native to tropical regions, they prefer relative humidity levels around 50%. Keeping a dish of water close by -- do NOT set the plant in a saucer of standing water! -- will help raise relative humidity. Curious as to why plants needs moisture in the air at all? Check out The Sill for answers.
2. Avoid fluoridated water
Recently, it's come to light that excess fluoride can cause leaf scorch/tip burn in houseplants. Homeowners using well water to water plants need not worry about this; those using municipality treated water should use distilled water if the water source is fluoridated.
3. Maintain ambient temperature
Temperatures that are either too hot, or too cold, can cause the leaf margins to brown. According to House Plants Expert, plants do well when the ambient indoor temperature is between 60-75 degrees. Avoid letting them sit in a windowsill during the cold winter months, or directly under a heat vent.
4. Prevent sun-scorch
For many plants, direct sunlight may cause brown tips on the leaves. Houseplants do best when placed in spots where they can access diffused light, instead of harsh direct sunlight.
5. Clean foliage with a damp cloth
If not used correctly, commercial products to make the leaves on houseplants shine, can also caused tip burn. Either make sure to follow product directions carefully or simply wipe foliage with a clean, damp cloth.
6. Allow chlorine to dissipate
Some municipality treated waters have chlorine added to kill bacteria. Unfortunately this chlorine can also damage houseplants if it is used to water them immediately from the tap. Allow an open container of water to set overnight, to let the chlorine dissipate, before using it to water houseplants.
7. Water consistently
Plants that experience drought stress are highly likely to exhibity burnt/browned leaf margins. Water plants consistently, making sure to not overwater, to prevent the leaves from drying out too much.
8. Don't overfertilize
An over-abundance of fertilizers applied to houseplants will accumulate in the potting soil, or on the surface as soluble salts. If concentrations become too high it will lead to salt toxicity and leaf tip burn. Feed plants lights to avoid this.
9. Protect from household chemicals
Acid cleaners have the potential to change potting soil to pH levels that are too low for good plant growth. Avoid spraying these cleaners where overspray may hinder plants. Also avoid allowing detergents to come into contact with plants; soaps can strip the waxy coating off foliage, allowing the leaves to dry out.
10. Minimize exposure to certain pollutants
Substances such as ethylene, carbon monoxide, and sulfur dioxide (common components in automobile exhaust) will also burn leaf margins if exposure is high. Urban dwellers with high pollution rates should avoid letting houseplants sit on the sills of open windows.