Chinese evergreen yellow leaves

Aglaonema

There are many hybrid varieties of the Chinese evergreen available which have been cultivated over the last century. This is because of their increasing popularity for indoor growers to use them as ornamental plants for room decoration.

These slow growing plant varieties includes, plain green, speckled, blotched and variegated types. One of the most popular and sought after is the silver queen which has leaves covered in silver mainly with some small green patches.

Foliage: The leaves are liner (elongated with parallel sides) or oval shaped which grow at the tip of the stalks. These leaves grow up to 30cm in length and about 5 – 8cm wide. An old mature plant will form a short trunk which can look similar to a yucca or dracaena, in the way the lower leaves come away and leave scared marks.

Flowering: During summer once the plant matures in growth and age it can produce very small flowers which then turn into berries. If these do appear they grow between the leaves and are quite insignificant.

Displaying: Wherever these are grown indoors they need to be provided with enough warmth. This is why many are grown in greenhouses or patios.

Caring: The level of care needed for this plant is quite moderate. The most important requirement is that they don’t reside in temperatures below 60ºF (15ºC). The good news is they can tolerate low lighting conditions, although I have seen it mentioned that it is only the all-green and not the variegated types that will tolerate low light.

Variety of factors could cause leaves to curl up

Q: I have an anglewing begonia that lives in my greenhouse. Its leaves began curling up in tight curls from the sides toward the middle and then turning brown. What do I need to do to treat this problem? Is the cyclamen toxic to small animals, such as cats? (e-mail reference)

A: Cyclamen contain toxic saponins, although the number of serious exposures is very low. The plant was investigated for toxic and pharmacologic properties in the 1950s and ’60s. However, there has not been much research since then that I can find.

Apparently, the highly toxic part of the plant is the rhizomatous tuber, which the cat is unlikely to get into. However, I would do my best to keep the kitty away from the plant if possible.

Q: I have an anglewing begonia that lives in my greenhouse. Its leaves began curling up in tight curls from the sides toward the middle and then turning brown. What do I need to do to treat this problem? My croton lost all of its leaves. I live in Florida and have it planted outside. When we got a cold spell, I covered the plant, but I guess it couldn’t take it, and all the leaves turned brown and fell off. How do I know if it is still alive? (e-mail reference)

A: I’m relatively sure it is still alive. The stems should be green under the bark. If not, the crown should have life left in it. I’m willing to bet that with the arrival of warm, spring weather in your part of the country, it will begin to releaf for you. At the very least, it should send up some new growth from the crown.

Q: I have an anglewing begonia that lives in my greenhouse. Its leaves began curling up in tight curls from the sides toward the middle and then turning brown. What do I need to do to treat this problem? We travel a lot in the Arizona area during different times of the year. We see many beautiful cottonwood trees in the sandy valleys. However, why do we only see mature, very large trees and no new young trees? It’s as if the trees are not reproducing. (e-mail reference)

A: I only have some guesses. Conditions are not satisfactory for the seedlings to become established. What you are seeing are males, because the females have been removed to prevent the annoying seedlings from coming up everywhere. What seed that is produced is consumed by the wildlife immediately.

Keep in mind that the desert is a stark place for abundant food, so anything that can be consumed is before it has a chance to establish. The next time you visit that part of the country, ask someone with the Arizona Extension Service the same question for a more cogent answer.

Q: I have an anglewing begonia that lives in my greenhouse. Its leaves began curling up in tight curls from the sides toward the middle and then turning brown. What do I need to do to treat this problem? Is it possible for an African violet to display stress because of workers suffering from colds or flu in an office setting? I have had two plants on my desk for quite some time, but have not had problems until now.

Prior to my office, they did very well in my home. Yesterday, both looked just fine. When I came in this morning, I noticed that the larger one had developed three droopy lower stems.

Nothing has been changed in their routine during the past eight months. The leaves and stems look fine, just droopy. They haven’t bloomed since last fall and don’t appear to show any signs of developing budded stems. Prior to this, they bloomed just fine. I water from the bottom once a week when needed. I use filtered water that is diluted with Peters African Violet Food. (e-mail reference)

A: How nice it would be to get a sympathetic acknowledgment from our houseplants when we are not feeling well. Unfortunately, this is not true. What has likely happened is that up to this point, the plants were silently suffering some kind of cumulative stressors, such as temperature, light, water, drafts, insects or disease, but didn’t show any symptoms until now. It is somewhat like going somewhere where you get into unsanitary conditions, but the symptoms don’t show up until a few days later, so you can’t make sense of what it is that ails you.

As a sweeping statement (I’ve said this many times before), the majority of houseplant problems are from two sources: overwatering and/or underlighting. I think the problem may be too little light intensity. In an office setting, the fluorescent lighting degrades through time. The problem is little noticed by the human eye, but is picked up by the energy preceptors in the plant’s chlorophyll mitochondria as it fades in intensity. This is why changing the fluorescent lights on a yearly basis is recommended for optimal plant health and vigor. Our vision will notice the duller light intensity about a year or two later, so get the bulbs changed to make it easier on our eyes. Unless the plants in the office are tolerant to low-light conditions, such as the sansiveria or Chinese evergreen, they will react much sooner than the human eye can make the detection. The fact they haven’t bloomed since last fall gives me a hint the problem may be the lighting.

Q: I have an anglewing begonia that lives in my greenhouse. Its leaves began curling up in tight curls from the sides toward the middle and then turning brown. What do I need to do to treat this problem? My sweet gum tree is starting to bud, which raised a question in my mind. Are the physiological changes (shedding of leaves or new buds) prompted by external factors such as too cold or warm, too much sunlight or not enough and moisture conditions? On the other hand, is the shedding of leaves or new buds brought on by some internal clock that couldn’t care less about any external conditions?

The reason I ask is the sweet gum has been dormant here in southern California since November (it dropped its leaves then). However, now it is sprouting buds although the weather is cold and rainy. Why is it coming to life now? (e-mail reference)

A: Woody plants are affected by all the factors you mentioned. One of the biggest triggers is the changing day length. As daylight hours shorten, the abscission layer begins forming. Depending on all the external and other factors involved, the leaves eventually senesce and drop off. The reverse happens in the spring. The buds pick up the lengthening daylight and begin to break out. Bud breakout is accelerated or held back by external factors, such as temperature and rainfall.

To our rational minds, we’d like to think that the plants would break bud when everything is perfect for them to do so, but it sometimes doesn’t work that way, which can lead to problems I won’t bother you with at this time.

Q: I have an anglewing begonia that lives in my greenhouse. Its leaves began curling up in tight curls from the sides toward the middle and then turning brown. What do I need to do to treat this problem? I have a five-year-old cherry tree. It has a few blooms, but never produces any cherries. I was told I needed a male tree to help produce fruit. Is this true and how do I tell a male cherry tree from a female? (e-mail reference)

A: No such tree exists. What you need to do is get another species of cherry tree (even a flowering cherry) that blooms at the same time as yours. What happens is that pollinating insects move between the trees and inadvertently carrying pollen with them. This causes fertilization to take place, which usually results in a very good fruit set.

Q: I have an anglewing begonia that lives in my greenhouse. Its leaves began curling up in tight curls from the sides toward the middle and then turning brown. What do I need to do to treat this problem? Last fall you had cautioned me against fertilizing the sweet gum while it was dormant, so I didn’t. Does the new budding indicate it would like some food (fertilizer) now? (e-mail reference)

A: I really wouldn’t fertilize now. I’m a big believer in responding to visible needs that show up rather than just providing nutrients in abundance when they are not needed. This can result in phenomenal growth, which is nice to think about and see, but it makes the plant more vulnerable to insect and disease problems. If the resulting growth appears to be sluggish, then I would consider giving the plant a little boost. Most of the time, fertilization at this stage of life is not needed.

Q: I have an anglewing begonia that lives in my greenhouse. Its leaves began curling up in tight curls from the sides toward the middle and then turning brown. What do I need to do to treat this problem? I received a ficus for Christmas. It is doing well, but it is in the original nursery bucket, so I want to transplant to a nicer pot. However, this is not the problem. I want to plant some queen’s tears around the bottom of the tree for the visual aspect and to keep my cats from using it as a potty box. Will these plants be compatible? Is there another type of companion plant that I can plant around the bottom of my ficus? (e-mail reference)

A: The queen’s tears, also known as a friendship plant, should be a good companion for the ficus. However, keep in mind that it is a drought-tolerant, tough, low-maintenance plant, so don’t overwater and you should be fine.

Q: I have an anglewing begonia that lives in my greenhouse. Its leaves began curling up in tight curls from the sides toward the middle and then turning brown. What do I need to do to treat this problem? Could you please give me a little advice on a Hansen’s cherry bush? I have had it for three or four years. It produced some fruit for me when it was young.

Last year, it had hundreds of cherry blossoms all over it. However, in just a few days, all the blooms fell off. I live in Illinois. Can you tell me what may have gone wrong and what I can do to prevent this? I have had two people tell me two different things. One told me I need to get a bloom booster, while another said maybe the wind blew them off the bush. (e-mail reference)

A: I think what you are calling the Hansen cherry is a Prunus besseyi, also known as the western sand cherry. It is used a lot in shelterbelts and small wooded areas to attract small wildlife because of its very edible fruit. I don’t know why you had a sudden loss of flowers, unless a cold snap occurred that caused them to abort. I suggest you try to be a little patient this spring to see what happens. If the blooms aren’t nipped by cold temperatures, then it should produce a mass of colorful fruit for you, until the birds find it!

Q: I have an anglewing begonia that lives in my greenhouse. Its leaves began curling up in tight curls from the sides toward the middle and then turning brown. What do I need to do to treat this problem? My wife and I are planning to plant a row of arborvitae for privacy. Our property slopes down to the area where we intend to plant the arborvitae. At the site, water collects from the natural flow of rainwater from other properties as it works its way to the sewer system. At times, the surface of the lawn is like walking on a wet sponge. Is the land too wet to plant the tree? If so, is there a tree that survives in a wet environment? (Tinley Park, Ill.)

A: If you plant the arborvitae, you’ll have to raise the bed to keep the roots from sitting in water for any length of time. About the only plant I can think of you might want to plant is the upright bald cyprus. The species is a beautiful, stately tree that would be too big for your intentions, but perhaps the upright form can work. It is a deciduous conifer, which means it drops foliage with winter’s arrival, but leafs out beautifully every spring. It would give you summer privacy at least. If you want to stay with arborvitae, the other suggestion I would make is to do some drain tile installation before planting to carry off the accumulated water. A good landscape design or contracting firm should be able to do that for you.

Q: I have an anglewing begonia that lives in my greenhouse. Its leaves began curling up in tight curls from the sides toward the middle and then turning brown. What do I need to do to treat this problem? Can I “top off” my river birches? How should it be done? Is July the best time? I live in New Jersey. (e-mail reference)

A: Topping a birch or any tree is the second worst thing you can do to it. The worst is to trim it at ground level. Birches are subject to a quick decline from topping, so please don’t do it! Hire someone who is a registered member of the International Society of Arboriculture. Go to http://www.njarboristsisa.com/ for additional information and help with locating someone who will do justice to your tree, but not murder it. In your part of the country, prune anytime after the leaves fully open, but don’t wait until August to do it because the pruning wounds might not heal in time before winter sets in.

Q: I have an anglewing begonia that lives in my greenhouse. Its leaves began curling up in tight curls from the sides toward the middle and then turning brown. What do I need to do to treat this problem? I have a devil’s ivy that I took from my mom, so it’s more than a few years old. I was wondering if there’s a possibility of reducing the size of the roots.

I’d like to cut one-third of the roots off and then repot. The plant is healthy (a bit spindly), but is on the brink of outgrowing its large pot. I really want to add some new growth clippings to the root-crowded pot. (e-mail reference)

A: There is no reason why your devil’s ivy shouldn’t be able to tolerate a root pruning. Root reduction often is done to keep plants from going into larger and larger pots, which at some point can be a physical challenge to handle.

Gardening or houseplant questions can be directed to: Hortiscope, Box 6050, NDSU Dept. 7670, Fargo, ND 58108-6050 or [email protected]

Note to e-mail correspondents: please identify your location (city and state) for most accurate recommendations

You’ve kept some plants alive for several months now. Feeling more confident, you bought up big at a recent plant sale. The next challenge is to keep the growing indoor garden happy and healthy.

If you’ve been watching your plants over time, you’ve probably realised they aren’t static; new leaves appear, plants droop if ignored, and the leaves might even change colour.

Like a new parent trying to understand the cries of a newborn, you need to learn to interpret the signs plants give to understand what your plant is experiencing.

Here are few common symptoms and what they may mean:

  • Wilting leaves
  • Plant/soil not holding water
  • Yellowing leaves
  • Roots at the surface or coming through drainage holes
  • Tips/edges of leaves turning brown
  • Flower buds form then drop off before opening, or shrivel soon after opening
  • Brown, burnt-looking spots on the top of leaves
  • Dropping leaves
  • Black dots on leaves, or brown marks with a yellow ring
  • Changing leaf colour

Wilting leaves

Loading…

We’ll start with a common but confusing one. If your plant’s leaves are drooping down, you first need to check how dry the soil is to get a bit more information; stick in a finger to the first knuckle to test it. If the soil is dry, the solution is simple — your plant needs water. However, if the soil is still wet, then your plant may have root rot, which is a fungal infection of the roots caused by overwatering.

Other symptoms include yellowing leaves, sudden dieback of part of the plant (or all of it!), and the plant becoming loose in the soil.

To check, remove the plant from the pot and look at the roots — they should be white or light brown. If they’re falling apart when you touch them, are soggy or brittle and are going dark brown, these are signs of rot.

Wash off the and trim off the affected parts; you’ll also need to trim off some leaves to keep it in balance.

If enough roots remain, dip the roots in a fungicide — such as a 3 per cent hydrogen peroxide solution — then repot it, using a clean pot and fresh potting mix. Water the plant in well, but then leave it alone until the top of the soil is dry when tested with your finger. Wash and disinfect the old pot before using it again.

If the plant’s roots are OK, it could be suffering from low humidity; see below for solutions.

Plant/soil not holding water

There are two possible causes for this — either the plant is root-bound, or the soil has become hydrophobic.

To check, knock the plant gently out of its pot and have a look; if its roots are tightly packed (called ‘root-bound’ or ‘pot-bound’), you know the plant needs to be potted up to a bigger pot.

If there’s still lots of potting mix left, it may now be repelling water — hydrophobic — which happens when potting mix or sandy soils are dry for a long time. The giveaway sign is water beading on top of the potting mix instead of soaking in. To fix this, soak the pot in a bucket of water or very weak solution of seaweed extract.

You can also try watering it with a solution of wetting agent, which reduces the surface tension of the water and allows it to penetrate the mix, but be aware most wetting agents aren’t classed as organic. You can make your own mix using agar agar; add one sachet to 5 litres of water.

Yellowing leaves

These yellowing leaves could be due to under- or over-watering, too much sun or cold daughts.(ABC Life: Juliette Steen)

Older leaves may yellow and fall off as part of a natural ageing process but if it’s happening too much — or to younger leaves — you know you have a problem.

This can be caused by too much sun so, if you think that applies, try moving your plant to a shadier area. Also check your plant isn’t in a cold draught from an open window, door or air-con unit.

Alternatively, yellowing can be caused by either over- or under-watering, so check for that, too.

Roots at surface of soil or coming through drainage holes

Got a root-bound plant? Don’t stress — upsize and repot.(ABC Life: Juliette Steen)

The chances are this plant is root-bound and so it will need a larger pot.

Gently remove it from its pot to check the roots. If they’ve started forming circles at the bottom of the pot or there are more roots that soil down the side of the pot, it needs a new home.

See here for potting up directions.

Tips/edges of leaves turning brown

If you’ve recently fertilised your plant, this could be a sign you’ve applied too much.

It can also be caused by softened water, which is often high in sodium or potassium.

Another cause is dry air. Many indoor plants are originally from rainforests, so have adapted to high levels of humidity. Without this, they can wither and brown, even when the roots have adequate moisture. Give them a spray every so often and remember to wipe down the leaves with a damp cloth to remove dust.

Plants with hairy leaves, such as African Violets or Rex Begonias, don’t like wet leaves so instead group plants together, or place them on a tray filled with small pebbles and a small amount of water. Another option is to move the plant to a naturally humid area, such as the bathroom or kitchen, if the light and temperatures there will suit your plant.

Flower buds form then drop before opening, or shrivel soon after opening

This could also be caused by low humidity; for solutions, see above.

Brown, burnt-looking spots on the top of leaves

Just like us humans, plants can get sunburnt too.(ABC Life: Juliette Steen)

If these marks correspond to where the light hits your plant through a window then you have your culprit — sunburn! Simply move the plant out of direct light and it should be fine.

It’s worth remembering that the sun in late summer and early autumn is still fierce but is lower in the sky in cooler months, so it will reach further into north and west-facing windows, which you might not notice during the week when you’re at work.

Dropping leaves

Weeping figs (ficus) and Bougainvillea have a habit of dropping leaves when they are moved and feeling stressed — usually they settle down to the new conditions.

But a more common cause is cold air or overwatering; other signs of overwatering include brown or yellowing patches on the leaves, dying leaf tips and, of course, wet soil.

Black dots on leaves, or brown marks with a yellow ring

Various fungal and bacterial diseases can cause this, and it spreads rapidly between plants when they are overcrowded.

Pick off infected leaves and put them in the bin, not the compost.

Mulch the surface with light stones to avoid fungal spores in the potting mix splashing on to new leaves, and ensure the plant has good airflow (not a full-on draught, just a gentle flow), with space between plants. Also avoid getting water on the leaves.

ABC Life in your inbox

Get our newsletter for the best of ABC Life each week

Changing leaf colour

If none of the above applies and your plant is generally healthy but just looking a bit pale and unwell, it could be experiencing a lack of nutrients. Apply a weak solution of liquid fertiliser for a quick boost.

In winter this may be enough, but in the warmer growing season you could follow up with a pinch or two of slow-release plant food, but don’t overdo it — twice a year is enough, and check the packaging for application rates.

Also keep an eye on light levels — plants that suddenly look a lot more lanky and “leggy” can be reaching out for more light, and this can make leaves change colour, too.

Leave a Reply

Your email address will not be published. Required fields are marked *