Houseplants 101

A PRIMER FOR HOUSEPLANT CARE

Congratulations on your interest in Houseplants. On a basic level, what they all require is water and light. Most also need appropriate soil and a well-suited pot (except air plants). At the next level you may want to think about fertilizing and learning about pest control.

Picking the Right Plant:

This will depend on a few things, but the main considerations should be what available light you have and how much time you have to invest in their care. Some plants want to be neglected and some want to be fussed over, so ask questions about these needs when you purchase and don’t lie to yourself about your level of commitment. If all goes well with the first one, you can always get another…or twenty!

Light:

This is a big one. Plants need light to live. And while some plants will tolerate low light, almost every plant would prefer bright, indirect light.

This is when the sun actually streams through the window and touches your plant. Most houseplants cannot tolerate direct light as they will burn. If this is what you have, consider either pulling them back farther from the window, adding sheers to diminish the light or using plants that prefer (ie need) direct sunlight like succulents, cactus or herbs. Note: the exception is morning direct light (East facing window) which is much milder, and most plants will tolerate this type of light fine. Also don’t forget the sun moves throughout the year so a South facing window that was fine in the winter may provide a death sentence in the summer. Pay attention.

Bright Indirect Light: When the light is very bright but doesn’t actually touch your plant. As noted, this is the preferred situation for most plants. This will usually come from windows facing South and West and very often East. Note: dirty windows, screens, outside foliage and large overhangs can greatly diminish your light so take these into account when accessing what you can provide to a plant.

Moderate Indirect Light: Most likely a table or corner a little farther into the center of a room with a good, bright window. North facing windows also often yield this type of light, especially in the winter months when the sun is even farther south. This type of light represents a grey area where you’ll just have to experiment to see what plants will be happy. It’s likely most plants will tolerate but not thrive in it. Succulents and cactus will not do well.

Low Light: This would be a wall or a corner farthest from any window or a room where the shades are never opened. No plant will love this kind of light, but there are some plants like Sanseveria (mother-in-law’s tongue), ZZ-plants, bromeliads and orchids which can tolerate low light. 

Some people try to overcome low light by moving plants outside occasionally to give them a little extra help. But be careful here. Usually what happens when this is done is the plant gets burned. Better to try using artificial lights. While not as good as the real thing, artificial lights can help considerably if no or poor natural light is available and we have seen some plants like pothos and philodendrons actually do quite well.

Water:

Learn about what type of plant you have. Some plants want to remain evenly moist all the time (the main reason people kill Maiden Hair Ferns). Some plants (the majority) like to dry out a bit on the top before they need another drink but will suffer if you let them dry out all the way. Some plants need to completely dry out (especially succulents) before they need more water. Ask questions or google your plant to find out what its preferred watering is.

As a general rule, the smaller the plant, the more often you water and vice versa. Really small planters (2” & 4”) might need to be watered 1x-3x per week depending on plant variety while 6” & 8” pots could go once a week to once every two weeks. Larger pots than this generally prefer every two weeks. This being said, there are exceptions to every rule. Sanseverias can go as long as 4 weeks without watering depending on the light conditions etc.

Observant Flexibility. Pay attention to how your plant is responding to your watering schedule and adjust as needed. In the winter you may only need to water once every three weeks or so but in the summer the same plant may want to be watered once a week. The amount of light and heat your plant receives will greatly impact its watering needs. Even things like whether you heat your house or not can make a difference.

Overwatering is the number one killer of plants. Most plants can recover from being underwatered (but please don’t read this as permission to take a three-week vacation and not water your plants!) But once a plant begins rotting from too much water, it’s too late. No plant can recover from this although sometimes you can save parts of the plant.

So how do you know when a plant needs water? Here are a few tricks to help you figure it out:

• Look at it. Is it droopy? Are the leaves curling? Is the soil pulling away from the sides of the pot? Does it look dry on the top? If the soil does not look dry, then please, don’t water it even if it is your normal watering day. The exception are plants that need to stay evenly moist (like the beguiling Maiden Hair Fern). For these types of plants, you should probably water them at least 2x per week unless they look downright soggy (or you see fungus gnats) which might indicate a drainage problem and will need further investigation.
• Weight. Pick your plant up after you first water it. Feel how heavy it is. When it needs water, it will be significantly lighter. 
• Stick your finger inside or use a chopstick or pencil. If your chopstick pulls up moist soil, you probably don’t need to water for a few more days.
• Moisture Meter. This is a great device that reads the moisture level for you. But be careful. On occasion a meter can malfunction. If it feels wrong (ie you haven’t watered in weeks but the meter is reading wet and it just seems weird), try another method.

Humidity and Misting. Many indoor plants are tropical and prefer a high humidity level. For this reason, using a mister frequently can really help to raise the levels. But don’t substitute misting for actual watering. You will never be able to provide enough water to the plant by misting alone.

How much should you water? As a general rule, water until you see it drain from the bottom. If you’re the kind of person who needs to have exact amounts, use a measuring cup to water your plant for the first time, taking care to go in smaller increments so you can tell how much it took to drain out. A 4” plant might use a half cup and a 14” plant might use a half gallon. Note: If the soil is exceptionally dry, you might have a situation where it cannot absorb water and it will run off immediately making you think the plant is being watered when it’s not. In these cases, water the soil very slowly and check the weight or use a chopstick to make sure water is actually reaching the roots.

How should you water? Most of us at Potted prefer keeping our plants in their original nursery containers which have excellent drainage and then putting the nursery pot in a pretty cachepot (which is just a fancy way of saying to put a pot within a pot). Then when we water, we take the nursery pot to the sink and water it there. This way there is no chance you will underwater or have water pooling at the bottom of the pot which can lead to rot and salt build-up. If this isn’t possible (ie, the plant is too big or in an awkward place) make sure the plant is not sitting in water after you’ve watered it as this will lead to rot very quickly. Most plants will usually wick up any excess water in their saucer within an hour or two. If there is still water in the saucer or cachepot after that, drain it out and consider watering it less the next time. And, as noted above, watering slowly is always a good idea to make sure the water is actually getting to the roots of the plant.

Soil:

Use the appropriate soil for your plant. Generally, most houseplants prefer potting soil and most cactus and succulents prefer cactus soil. The difference is in how quickly the soil will drain. Potting soils tend to be “heavier” (ie they retain water) while cactus mixes are “lighter” (ie more porous so they don’t hold water).

There is a myriad of things you can add to soil (peat moss, charcoal, perlite) to make it go more or less in either direction, but generally a good store-bought mix will serve you well and you don’t need to stress all the amendments too much. The only caution here, don’t use garden soil! It is way too heavy for almost any houseplant and will most likely smother their roots.

Containers:

Plants need drainage. Always make sure that whatever container you decide to use has drainage. As we mentioned in our watering section, it’s best to use a pot with no drainage as a cachepot so it acts like a saucer for the nursery pot.

If you must use a pot with no drainage:

• Water very sparingly.
• Add charcoal to the soil to mitigate bacteria.
• Don’t bother with rocks on the bottom. All it does is take away growing space for the plant and it does nothing to stop rot.
• Accept that you will most likely have to replace the plant at some point and be good with that.

Pick the right size pot for your plant. If a pot is too big for your plant, besides looking odd, it can also create a space for holding too much water which can lead to rot.

Fertilizing:

Think of fertilizer as vitamins for your plant, not food. Plants make their own food but occasionally the soil they are drawing from could stand some “re-energizing.” This is where fertilizer can be beneficial. But be careful with fertilizers. Using too much can do as much harm as good.

When choosing a fertilizer, time release varieties are the best as they release slowly into the soil and won’t burn the plant. But only use them during the growing season and make sure to follow the directions on the packaging. MORE IS NOT BETTER. If you just can’t help yourself and you really feel like you need to pamper your plants, try using sea kelp. It can be diluted in the water and you can use it every time with no ill effects on the plants.

Pests & Diseases:

Healthy plants rarely get pests or diseases. When a plant is stressed by either over or under watering or too little light it becomes susceptible to pests and disease. The best defense against any plant ailment is to keep your plants healthy with consistent care.

Types of pests. Scale (hard bodied), mealy bug (soft scale), aphids, spider mites and fungus gnats are the most common. Most often these pests can be found on the underside of leaves, at stem and leaf joints and on new growth. Scale, mites and aphids suck the plant’s sap causing the plant to lose its nutrients. This causes leaves to discolor, curl, dry and shrivel…eventually falling off. And while fungus gnats are generally not harmful to the plant, they can be annoying to have in your home.

The best cure for all pests is early detection and quick treatment. If the plant can take a jet stream of water, this will knock most pests off. Dabbing rubbing alcohol on an infected area is also quite effective. Neem Oil Spray is another good treatment method. A solution of 1 tsp. of dish detergent with 1 gal. of water can be sprayed on infected areas. For fungus gnats, the most common culprit is damp soil so cut your watering schedule back and don’t water until the top 1-2 inches is dry.

Be persistent. Multiple treatments are often needed. If one method doesn’t work, perhaps another will. And always quarantine infected plants. As mentioned above, a healthy plant will rarely get pests or diseases but why take a chance?