Garden Answers

Houseplants

Should I be doing something differently with my houseplants during winter?
Why is my new ficus tree losing its leaves?
My houseplant's leaves are turning yellow and falling off, what's going on?
What are these blobs of white stuff on my houseplants and what do I do?
The leaves of my palm tree look kind of "bronzy." What's going on?
Should I worry about the sticky stuff on the leaves of my schefflera?
What is the best care for a fern?
Can you explain the different Hibiscus plants?
How do we care for a gloxinia?
Why are the leaves dying on my Wandering Jew?
What do I do to keep my poinsettia for next year?
How can I be sure my Christmas cactus will continue to bloom?
Can I prune a ficus tree? If so when?

Question: I have a few houseplants that just don't seem very happy through the winter. I don't really treat them any differently than any other time of year. Is there something I should be doing differently?

Answer: Actually, that's a good question as houseplants often do need different care through the winter months. One of the main things that you can do is to adjust your watering schedule. Shorter, cooler days and less air movement (windows are closed and swamp coolers are off) cause many houseplants to slow their growth and sometimes become almost dormant. Consequently they don't take in as much water. An easy way to check your houseplants is to simply stick a finger down into the soil. If it's dry, give it a nice soaking, making sure to drain any standing water from its saucer, and then let it dry out slightly before watering again.

After that, be sure to keep an eye on them! Watch for any insect problems (common when plants are over-watered) so you can correct the problem early on. If you catch them early, it's fairly easy to get rid of pests, but once the plant is overrun it can be much more difficult. If you do see insects and aren't positive what they are, the best thing to do is to catch a few in a Ziploc bag and bring them in to us for identification. Proper identification is the key to getting the problem fixed. There are actually some insects that could be beneficial to your houseplants and killing them off might do more harm to the plant than good.

The final thing you can do to help your houseplants through the winter is to give them an occasional shower! They like to be clean, and need the dust cleared off their leaves every so often. Depending upon the size of your plants, you could use the kitchen sink spray or put it into the bathtub and turn on the shower. Be sure to clean off the undersides of the leaves too. Contrary to what some people think, a shower once a month DOES help keep insects down and does NOT encourage diseases.

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Question: My new ficus tree is losing its leaves! What's wrong and what can I do?

Answer: Join the club! Ficus trees(also known as weeping fig) are finicky houseplants that are very sensitive to environmental changes. Basically, these plants are fuddie-duddies that don't like change. They like the same monotonous, boring routine day after day after day….Ficus tell us that they're unhappy by dropping their leaves. Without knowing specifics, there are a few things you could check on which could cause it to lose its leaves. First, has it been moved recently? Are there any drafts nearby? If you've had your ficus in a spot it seems to like, even a move a few feet away may traumatize it. (We find that true even here in our greenhouses!) They also prefer moderate to warm temperatures free from drafts of any kind (keep them away from the heater vent, the swamp cooler, and especially doors to the outside where they can get a blast of cold are in the winter or hot in the summer) and medium to bright light.

Next, check the watering. Ficus need their soil kept evenly moist; if they're too dry, or sitting in drained water, they could drop their leaves. Leaf drop is actually a symptom of a plant under stress. The plant kind of shuts down so it can cope with the change. During this time, it's not drawing in water at its normal rate. However, most of us see leaves falling and assume the plant needs more water when, in fact, we're just adding more stress to its system! This is when it's most in danger of being over-watered!

Finally, use a good houseplant fertilizer. You can use Osmocote, a slow-release fertilizer, once every 3-4 months, or Miracle Gro once a month with your watering. If all those factors seem fine, give us a call and we'll see if we can't find out what else may be going on with your ficus. Hope this helps.

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Question: My houseplant's leaves are turning yellow and falling off, what's going on?

Answer: Well, without looking at it, it's difficult to say. The best thing would be to bring a piece of it so we can look it over, but barring that, there are a variety of factors to consider: it could be caused by water-either too much or too little, insects, too much or too little light, or fertilizer. Then again, depending upon the type of houseplant, losing its leaves may actually be normal! Many of us tend to overwater our houseplants in the winter when plant activity is actually slowed and may need less water overall. With a little more information, we'd probably be able to eliminated possibilities, and get to the root of the problem!

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Question: I have blobs of white stuff on my houseplant. What is it and what do I do?

Answer: The most common cause of those white blobs would be mealybugs. Mealybugs look like white, fuzzy, cottony masses on the leaves and stems, and can be difficult to control. Before you do anything else, you need to isolate the infested plant from any other plants you have. These guys will spread out!

I recommend a two-pronged approach to getting them under control. First, give it a weekly spray with a good houseplant insecticide or an insecticidal soap. Coverage is extremely important, so be sure to thoroughly cover both the upper and lower surfaces of the leaves. Next, be sure to use a systemic insecticide in the soil. You'll need to reapply it every three to four weeks to get the upper hand. Look at it as a battle of attrition; it's either them or your plant-you need to simply wear them away. Don't be discouraged, and realize that it will take about 2-3 months before you'll will the war. If, after that period of time your plant is still reeling from these guys, you may need to cut it as a loss in order to protect your other houseplants from a similar fate. If you're not sure, bring us a sample in a baggie and we'll be happy to talk about what to do.

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Question: The leaves of my houseplant palm tree are getting brown. They look kind of "bronzy." What's going on?

Answer: As with a lot of houseplant problems, it helps if I can look at a sample. Going on what you've told me I can give you a few things to look at. Check the watering of your palm tree and the humidity level. Either of those could lead to that bronzy looks. I'm guessing, however, that the problem is probably spider mites. They're little teeny tiny guys almost impossible to see with the naked eye that mostly hang out on the underside of leaves. They're related to the spider family (arachnids), and can spin a fine web, but by the time you see signs of webbing, they're already way out of control. Spider mites suck up sap from the leaves which is what causes the stippling, or fine spotting, that you see as a bronzing or silvering look to the foliage.

The real problem is the number of these guys. They have an extremely fast turnover generating a new generation as quickly as every ten days to two weeks! So how can you keep on top of such fast multipliers? The easiest (and very effective) treatment is to give them a cold shower. No kidding. Shower them with a hard jet of water in the sink or shower, at least once or even twice a week (or outside with the hose in the spring and summer) and scrub the leaves. Be sure to blast the water on the underside of the leaves as well since that's the primary residence of the spider mites.

There is also a series of pesticide sprays that work well. (Note that these act only on the adults-they have no effect on the egg stage.) Make sure that the spray is labeled for mites or your application may be a waste of time. As with the cold water shower mentioned above, be sure to spray the plant thoroughly, paying special attention to the underside of the leaves. You will need to repeat spraying with a total of three applications timed a week apart. Take heart and be persistent, these guys can be beat, but it takes diligence! Hope this helps.

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Question: There's a bunch of sticky stuff on the leaves of my schefflera. Anything to worry about?

Answer: The sticky stuff generally means that you have a piercing/sucking insect feeding on your plant. That could be a number of different insects-a sample to look at would help. It could be Mealybug, aphids, or most likely, scale. Scale form a hard shell over the top of the insect which serves to protect it from predators and sprays. That, of course, makes controlling them somewhat difficult. First, I'd isolate the plant. The last thing you want is scale spreading to other plants. Keep the problem localized. Spray weekly with a good houseplant insecticide (I like to use Fertilome's Whitefly & Mealybug.), and use a houseplant systemic insecticide every three to four weeks. Treat it consistently, and you should see improvement in two to four months.

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Question: What is the best care for a fern? Some have said to just mist the leaves and don't water the soil, some have said it will need a ton of direct sunlight, and others have said that it is a very tough plant and can pretty much live anywhere in the home with moderately moist soil.

Answer: Ferns are funny plants. They can be maddeningly difficult to grow, but if you can find the combination of the right place, the right plant, and the right care, they really are "cast iron." In a nutshell, what ferns want is bright, indirect light with moderate temperatures and high humidity. Those last two are what give most people problems. Our naturally dry climate makes it tough. First, find a place with the right light. If you have a bright bathroom, they usually do well there. Also, surrounding them with other houseplants can help raise the humidity. One trick that works pretty well is to use what's called a "humidity tray.' What this is is a large, oversized saucer that you fill with gravel. Pour water into it until the saucer is almost full. Put the plant on top of the gravel (make sure that the bottom of the pot is out of the water). As the water in the saucer evaporates, it raises the humidity around the plant.

Watering is a little tricky too. You want to maintain a steady supply of water without waterlogging the potting soil. When you water, make sure that the soil in the pot is wetted completely, that is, there should be water coming out of the drainage holes in the bottom of the pot. For this reason, I like to water in the kitchen sink. Just misting the plant will NOT provide enough water for your fern. In fact, I'm not a big fan of misting houseplants because it doesn't provide consistent humidity (unless you're misting eight or ten times a day!). The plant undergoes some physiological changes, thinking it's nice and humid when you mist, but then the water evaporates, it's dry, and the plant needs to change back. That can cause stress in the plant. Hope all this helps.

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Question: I'm a bit confused: I was looking for a houseplant that I call a Hibiscus, but have been told they are outdoor plants here. I've also heard people call a Rose of Sharon a Hibiscus plant. Can you help me out here?

Answer: You're not the only one who's confused! When folks call with hibiscus questions, we usually end up asking THEM several questions to determine exactly which plant they're interested in. The tropical hibiscus likes bright, indirect sunlight and a minimum temperature of 55° in the winter months, which is why it's considered a houseplant here in the valley. Tropical hibiscus is also the only of the hibiscus in bright oranges and yellows.

There's also a perennial hibiscus (Hibiscus moscheutos) which is also called Southern Belle Hibiscus that likes our hotter climate and can survive our winters here. True to the nature of a perennial, it'll die back each year and come up again the following year. It can get 3 to 4' tall with red, white or pink blooms 5 to 6" wide that are absolutely beautiful! They need regular deep watering and protection from the wind.

Rose of Sharon (Hibiscus syriacus) is a woody shrub that grows even taller, getting 8 to 12' tall, often with an upright, vase-shaped growth habit. These usually flower mid to late summer and are covered with lovely blooms-single or double-which vary in color (white, lavender-pink, blue, purple-pink) according to the variety. Hope this clears up the situation a bit.

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Question: My mom has a plant called Gloxinia and we were just wondering when its done blooming do we just clip off the dead blooms from the stem half-way, or do we break them off like begonias?

Answer: Once the blooms dry up, I like to cut the flower stems off as low as I can get. Breaking them off is a little risky because sometimes you pull off more than you intended. On Gloxinia, use a small pair of pruning shears or just use some scissors.

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Question: I recently bought a Wandering Jew and I was wondering why a few of the leaves are turning brownish-yellow and crunchy? It's in a well-lit area and I water it when it's dry. What do I do with the leaves that are dying? Do I trim them off?

Answer: There can be several things that are going on. The most common problems have to do with watering. Either extreme can cause what you're seeing-too much water or too little. Most of the time, the problem is actually too much water. When you water the plant, water it thoroughly (there should be water coming out of the drainage holes). I like to fill the pot up once, let the water soak in, and then fill it up a second time. Then, you need to let the soil dry a little before soaking it again. Dig down into the soil and feel how wet or dry it is. In a 10" hanging basket, I'd let the soil dry out down to a depth of an inch or so. If the plant is sitting in a saucer, you want to soak it well enough that water collects in the saucer. However, never let your plant sit in water in the saucer. If the plant is small enough, water it in the sink so the drainage water just goes down the drain. If the plant's too big to do this, use a turkey baster to suck the excess water out of the saucer.

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Question: I need to know what to do to keep my poinsettia for next year.

Answer: If you want them to bloom again next year, your poinsettia will need a little more attention. Treat it like a houseplant over the winter. Place it in a warm, bright spot, water when it's dry to the touch, and fertilize every two weeks. Many people then move them outside into a mostly shady spot in the spring and summer. In early June, prune your poinsettia. At the end of September, place it in complete darkness for 14 hours/day. You can put it in a closet to do this, just be sure to bring it out during the day so it gets the light it needs to grow well. You can also put it in a back room that at isn't used much. The main thing is that it doesn't get light consistently at night. You should begin to see colored bracts in early November, and have a nice-looking plant again by Thanksgiving!

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Question: How can I be sure my Christmas cactus will continue to bloom?

Answer: The Christmas cactus is a relatively easy plant to care for if you follow a few simple rules of thumb. While these guys need bright, indirect sunlight to grow well, they, like the poinsettia, are light dependent for their blossoms. They need a number of uninterrupted hours of to trigger their bloom. Consequently, if your Christmas cactus is in the family room where you normally have several lights on throughout the evening, it may not be getting the 'dark time' it needs in order to generate budding.

Though this is a member of the cactus family, its segments are more succulent-like and require more water than most cacti. That said, avoid overwatering! Give your plant a nice soaking and then allow it to dry slightly before watering it again. Use a good houseplant fertilizer (Miracle Gro works well) once or twice a month. If you're having a problem with getting a consistent bloom year-to-year, check the lighting and overall care of the plant. Sometimes folks rush to repot their Christmas cactus, but I'd like to caution you about that. Most Christmas cactus actually prefer to be more crowded than not. We suggest repotting more as a last resort if all else looks fine.

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Question: I have a question that I hope you can help me with. I have a Ficus tree, which I have had about 4 years.  Even though we have vaulted ceilings, it is getting a bit out of hand.  Can I prune it? If so, when is a good time?

Answer: Pruning a Ficus is really pretty easy. What you want to do is to cut the plant back while still retaining its natural shape. Most Ficus grow with a vase-shaped bottom and a spreading, rounded, umbrella-like top. You want to encourage the plant to spread out a bit. Remove any branches that are growing back into the center of the plant; you want the branches to spread outward, away from the center. If you have two branches that are crossing, plan on removing one to eliminate the conflict.

When you do prune back a branch, be sure to cut it completely back to a side branch. Don’t just cut the branch back any old place, leaving a stub; cut it off so that that side branch is now at the end. The side branch that you cut back to should be at least 1/3 the diameter of the branch you’re cutting off. I hope this is making sense to you—describing pruning techniques in just words is difficult!

 

Another thing to keep in mind is not to cut off more than 1/3 of the foliage of the plant at any one time. If you need to take more than that off, do what you can now, allow the plant to recover (two or three months), and then do the rest. Doing the pruning gradually in this way can avoid stress on the plant.

The last tidbit of advice I can give you is to put a drop cloth under the plant before you start pruning. Ficus have a milky-white latex sap and they can really bleed when you cut them. This isn’t a problem for the plant, but sometimes that sap will drip off and gum up the floor underneath. The bleeding will stop after a day or two. Hope this helps.

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