Questions tagged [diseases]

For questions related to plant diseases.

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6
votes
3answers
2k views

What are these white streaks on my tomato plant?

I've also seen similar streaks on my basil's leaves but not as pronounced.
18
votes
4answers
4k views

What else besides calcium deficiency could be causing tomato blossom end rot?

I've been using "Tomato Maker" (4-2-6) fertilizer, which supposedly has enough calcium to prevent blossom end rot, but I'm still getting blossom end rot on my super marzano tomatoes (no BER problems ...
29
votes
7answers
105k views

What are these hard white/brown spots growing on my houseplant?

A little more then an year ago I got six palm trees (two vases). It was the Californian equivalent of an Areca palm (the guy in the nursery suggested this one after I asked for an Areca for its air ...
15
votes
4answers
35k views

Sudden Outbreak of Yellow Leaves on Tomato (and Other) Plants

My mother was in a panic this morning. She called me over to help her with her garden because many of her tomato plants had suddenly developed yellow leaves, many of which (but not all) also have ...
17
votes
6answers
44k views

What is happening to my chilli plant? How can I help it?

Some white spots appeared recently on my Twilight chilli plant (indoors), on some leaves brown spots start appearing in the middle. First I thought - aphids, but it doesn't quite look like insects. Or ...
12
votes
2answers
3k views

What is this brown, shell-like thing growing on the stalk of my avocado plant?

Could you please help identifying this brown shell-like thing growing on the stalk of my avocado plant? There are several of these. It looks like a little shell (with the appearance of a woodlouse's ...
11
votes
2answers
1k views

What is the problem/disease that causes bobbly peach tree leaves?

What is the likely cause of the bobbly forms on the leaves of a peach tree? Does it matter or is it just some natural anomaly that doesn't affect the tree's health? If is it a concern how can it be ...
14
votes
3answers
5k views

Why have my tomato leaves started yellowing at the base?

One of my tomato plants (Better Boys if that matters) has a few leaves that have started yellowing on the lower branches. Not sure if they aren't getting enough water, or if they are diseased or what. ...
7
votes
1answer
28k views

My Areca Palm is dying

I bought a 5ft areca palm about a month ago. About two weeks after I purchased it, I noticed some leaves had spots and others were turning brown. Initially I thought it was normal but more leaves seem ...
4
votes
1answer
2k views

What is wrong with my lemon tree? [duplicate]

Below is a picture of my lemon tree, which now have some sticky web infection. See left corner on the first picture. On the second picture is a close up of something that is being spread from the ...
6
votes
2answers
376 views

Is powdery mildew spreading through my garden?

I noticed this white fungus a few weeks ago on some flowers in my garden which I ignored. But now it's appearing on my zucchini leaves. I was under the impression the fungi are plant specific, but ...
6
votes
1answer
383 views

What's affecting this tomato plant? [duplicate]

Can anyone tell what's wrong with this tomato plant? Is it disease or deficiency? My areas been having issues with late blight the last few years. One spot seems to have a concentric circle around it ...
5
votes
3answers
1k views

What's wrong with my tomato plant?

This is a Great White plant, planted about 30 days ago. It has yellowing leaves with black spots, all tge leaves are drooping, and there are very few flower buds. I'm afraid I might need to dispose of ...
5
votes
1answer
15k views

What is the white, powdery, substance on my hibiscus?

We live in Southwest Florida. About a month ago, or maybe a little longer, I trimmed back our hibiscus plants. Today, I just noticed this mass of white, almost powdery, substance on the branches and ...
14
votes
1answer
2k views

What are these brown, cap-shaped mushrooms on my birch tree?

I live in Massachusetts and have several birch trees in my yard. One of them has brown, cap-shaped mushrooms growing in groups up and down the trunk. As you can see, the tree has a big crack in the ...
4
votes
1answer
122 views

How to heal this needled plant?

This little guy is suffering and I'm not sure how to help him out. Any ideas?
9
votes
2answers
8k views

What is happening to the leaves of my avocado?

I have an avocado plant in my outdoors balcony. It's been growing nicely, but there are small brown dots/holes in the leaves for some time now. I don't see anything in the underside of the leaves, and ...
12
votes
5answers
150k views

What causes cucumber leaves to turn yellow, brown, wilt, die, and the plants to stop producing?

Every year it seems my cukes will go gang busters then suddenly the leaves turn yellow (starting with yellow spots), then turn brown, wilt and slowly die off. This all happens from the root crown and ...
11
votes
3answers
42k views

Why does my blueberry bush have brown/scorched leaves?

I recently purchased a dwarf Northsky blueberry bush from a mail order company. When I recieved it, roughly 15-20% of its leaves had the appearance of being burned or scorched; the bad leaves were ...
10
votes
1answer
1k views

Why do my tomato leaves look powdery?

I have a threesome of tomato plants planted in on my porch. All three have some leaves that seem to be a bit white and powdery. One of the leaves has even started to turn a bit brown. I don't think ...
7
votes
1answer
7k views

Kentia palm dying. Advice? :(

I bought a kentia palm some months ago, and during the last week one stem/group of steams is turning out yellow. Also there are some big white stains on the leaves. Some leaves also have small white ...
5
votes
1answer
488 views

What is wrong with my Mango plant?

I planted a mango seed this spring. And it went good. But growth stagnated after a while and totally stopped. Then I noticed some bulgy excrescence on the top, with a very dark almost black color. I ...
5
votes
2answers
803 views

Need help with identifying the disease on my mango tree and a possible cure

It started with me seeing dark spots appearing on the leaves of my mango tree, which grows in my apartment. When I looked underneath the leaves I saw something white growing there. Now it has spread ...
4
votes
1answer
4k views

Dry brown patches on cayenne chilli plant leaves, leaves starting to curl, tiny black spots

Note: I have posted a previous question regarding my chilli plants, its details may help in diagnosing this new issue. You can see it here: White, fur like strands and spots on underside of chilli ...
4
votes
1answer
22k views

Young avocado plant has brown spots spreading on leaves

I have been growing in my flat an Avocado plant sprouted from a seed in December. It developed well, up until about a month ago, but then brown dots started forming on the leaves, the oldest leaves ...
3
votes
0answers
100 views

White map-like tomato leaves (hydroponic) manifesting [duplicate]

I am growing cherry tomato using kratky hydroponic method and ive seen these map-like lines manifesting on a number of leaves. I had to remove the infected leaves to control the infection if you will. ...
3
votes
1answer
22 views

Can I do anything about horse chestnut leaf miner?

I have a young horse chestnut tree in the garden, about twelve feet tall. Most of the leaves are discoloured by leaf miner. Can I do anything? I am in London UK.
10
votes
2answers
5k views

How do I treat rhubarb rust?

I have a small rhubarb plant and one of the stems has gotten some rust on it. What should I do? (there are only 3 small stems on the plant)
9
votes
1answer
18k views

What is causing the bark on my crabapple to crack and peel off?

I have a flowering crabapple in my yard whose bark has several large areas where it cracks and curls away from the wood underneath: Hover over any image for description / click for full size I don't ...
9
votes
4answers
18k views

Beet plant - leaves turning yellow-brown

I have a beet plant that I grew from seeds. They started off great and healthy. In fact I plucked some leaves to use in a salad. After that some of the leaves are turning yellow and drying up. What ...
8
votes
2answers
1k views

Brown spots around the veins on a hot pepper plant's leaves

I noticed this on some on my Carolina Reaper plants. A lot of the leaves have this kind of spots surrounding the midrib and the veins. The plants grow indoors in 5l pots but I kept them in the garden ...
8
votes
1answer
3k views

Is something wrong with my zucchini plant?

I have three large zucchini plants in my garden, and all three have been producing nice fruits for a few weeks. The last couple days, one of them has started to turn yellow and sickly: I've never ...
7
votes
1answer
6k views

White, fur like strands and spots on underside of chilli plant leaves

I am growing scotch bonnet, jalapeno and cayenne pepper plants indoors from seed. The scotch bonnet plants have what looks like white fur growing around the veins on the underside of their leaves. ...
7
votes
1answer
5k views

Grapes leaves too dry - is that normal?

Recently I noticed my green grapes leaves don't look too good. There's nothing like scales or ants or any other sign of parasites. Only older leaves are affected, new ones are fine as you can see on ...
6
votes
1answer
2k views

What is this disease on my Basil?

I've planted Basil (from a pot) outside and it's been very wet in the last few weeks. The plant has now got these grey spots on it. What is wrong with it?
5
votes
1answer
5k views

Why are the lower leaves of my tropical Guava yellowing and dropping?

I had a Century Guava (世紀芭樂) shipped over from Taiwan to zone 9 California. It is nearly 6 feet tall. I planted it in the biggest container that IKEA sold, 20 inches wide, 2 feet deep. I drilled many ...
5
votes
3answers
804 views

What's wrong with this Photinia fraseri tree?

I've got three Photinia fraseri trees in my yard in Tucson, Arizona. They were planted last May (2013) and now in September (2014), one of them is turning entirely brown and losing all its leaves (...
5
votes
1answer
5k views

Dracaena Massangeana: Leaf spots on new growth

Over the course of the past week I noticed spots developing on some of the new leaves. These start as faint yellow halos and seem to develop a brown core quickly over the course of a few days. The ...
5
votes
1answer
378 views

Should I remove brown, cap-shaped Birch Polypore mushrooms from my tree?

I learned from this question that my birch tree is infested with Birch Polypore mushrooms. For two reasons, I'm wondering if I should remove them. First, even though they grow because the tree is ...
5
votes
1answer
611 views

What are these black spots on white splotches appearing on my tomato seedling?

Here are pictures of the infected leaves. I cut them off the plant as soon as I saw them today. Click for full size Here are close-ups of the most infected leaf: Click for full size What can I do ...
5
votes
1answer
4k views

Tomatoes…what is the difference between early blight and late blight?

What are the differences in early and late blight of tomatoes? Can you cut off affected areas of one or both to prolong the life of the plant? What can one do to prevent this disease, what can one do ...
4
votes
1answer
213 views

White stripy things on trunk are killing my plant

Something is killing my plant. The leaves are loosing their colour. On the branches, there is a white, stripy discharge that's slowly taking over the entire plant. Can someone identify this and tell ...
4
votes
2answers
296 views

How to tackle this disease on an apricot tree

We live in Vienna, Austria, very near the Danube river. We planted this apricot tree back in spring of 2015 as a small tree bought from a local nursery. It has been growing very quickly and was ...
4
votes
1answer
1k views

Why are the leaves on my capsicum plant curling and turning brown?

Does anyone have any idea what's happening to my capsicum plant and what I should do about it? There are no visible bugs on the leaves.
4
votes
1answer
123 views

Home-made Solution for White-Spotted Curley Leaves on Pepper Leaves

I had bought 10 pots of peppers a while back. Not all of them seemed healthy, but since they had the fruits, I thought I can use the fruits and bin the pots if I can't keep them. I was keeping them in ...
4
votes
2answers
9k views

Monstera Deliciosa plant with brown crud on the leaves

I have a pot plant with Swiss cheese kind of foliage that has got some problem possibly some sort of parasite or fungal infection, I have no idea. It's like red-brown rust that brushes off fairly ...
3
votes
1answer
3k views

What is wrong with this tomato plant with yellow and black spotted leaves? [picture]

What is wrong with this tomato plant? The yellow with black spots has been spreading through the plant. I am hoping someone knows exactly what this is and how I can treat it or prevent it.
3
votes
1answer
1k views

Is this spotting on my schefflera houseplant caused by alternaria?

I've had a medium-sized schefflera or 'umbrella' houseplant for about five years now, and it might have been as old when I first got it. Lately, I have noticed black spotting on some of its lower ...
3
votes
1answer
16k views

Kentia palm leaves turn brown

I have bought a 7 foot Kenia Palm about 6 weeks ago and keep it indoors in spot with indirect light. The palm gets 1/2 gallon of water once a week and I added half a tablespoon of 20-20-20 all ...
3
votes
1answer
3k views

Cucumber with bacterial wilt, what to do to save other plants?

On Saturday, my cucumbers looked perfectly healthy. On Sunday, half of one of my cucumbers had very wilty leaves. On Monday, the other half of the cucumber's leaves were all wilty. I have seen ...