Watering properly is one of the most important skills in indoor plant care. It is easy to forget about plants until they start to droop and equally as easy to water them much more often than necessary. Many are also guilty of leaving water in the saucer after irrigating which can lead to a multitude of problems. Each of these problems may lead to root damage or erratic and stunted growth.
There are a few things to consider when determining how to water your houseplants: What type of plant do you have? Plants are not all the same in their water requirements. If you have a plant that requires a lot of light, it may need more frequent watering. What size is your plant? Large plants will need more water than small plants. The volume of your container may determine the water needs. If your container is too small for the plant it is housing, it may need more water. The amount of water already in the soil may determine the frequency of watering. How much light does your plant require? If you have a plant that requires moderate to low light conditions, they are less likely to need water as often as those that require more light.
If you see the tips of your plants turning brown and you are sure that over- or underwatering are not a factor, chlorine, over-fertilizing and fluoride toxicity are likely culprits. These will cause browning of the tips, referred to as tip burn or leaf scorch. While tip burn will not kill the plant, it will cause the leaves to be unsightly.
Many common houseplants are sensitive to fluorine and chlorine, such as peace lily (Spathophyllum), spider plant (Chlorphytum comosum), peacock plant (Calathea makoyana), corn plant (Dracaena fragrans) and several other tropical plants. If you only have a few of these, you can use distilled water. You can also alleviate this problem by using rain water or leaving water standing for a few days to allow the chlorine and fluoride to dissipate before putting it on your plants. Also, avoid using fertilizers with superphosphate as one of the ingredients. You can reduce the toxic effects by controlling the pH of the potting mix you use. These sensitive plants should be grown in a potting mix with a pH of 6.0 or higher.
When containers have saucers to catch water as it flows through the soil, the saucer should be emptied after just a little while. After applying fertilizers, water left in the saucers may cause an excessive build-up of soluble salts. High levels of those salts can cause root damage and a decline in growth. Over fertilization can have the same effect. To avoid over fertilizing, try some of these recommended routines: Never apply fertilizer, dry or liquid, to dry soil, as root damages may occur. Never apply more than the recommended dose. Fertilizing should be decreased during the winter months when most plants go into a slower growth or dormant period. Fertilizing is most beneficial when plants are actively growing in the spring and summer. Plants that have been over fertilized should have large quantities of water applied to leach accumulated salts from the soil. Allow the water to run through.
Among other pests, overwatering can also create an ideal environment for fungus gnats. The adult form of these gnats is mostly a nuisance, but the larval or immature stage can cause damage to your plants. Fungus gnats require high moisture conditions and decaying organic matter. The immature gnats feed primarily on fungi growing on the decaying material in your soil but may begin to feed on the roots and the crown of your plant. Damaged plants will soon have poor color, lack vigor and experience premature leaf drop.
When do you know it’s time to water? Feel the soil by pushing a finger an inch or so below the surface. If the soil is still moist, there is no need to water. There are also water meters available.
More is almost never better when it comes to plant care. Careful watering, fertilizing and inspection of your plants will keep them happy, healthy and away from the compost pile! For more specific advice about your houseplants you can call your local extension office. Atlantic County residents can contact the Master Gardener Helpline at 609-625-0056. Cape May County Residents can call 609-465-5115, ext.3607.
Do you have a gardening related question you would like answered here? Please forward your questions to Belinda Chester, Master Gardener Program Coordinator, Rutgers Cooperative Extension Office, 6260 Old Harding Highway, Mays Landing, NJ 08330. You can also submit questions at Rutgers-atlantic.org/garden or email them to firstname.lastname@example.org; please include “garden question” in the subject line.