Questions tagged [diseases]

For questions related to plant diseases.

153 questions with no upvoted or accepted answers
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7
votes
1answer
306 views

Pinus sylvestris yellowing problem

I'm pretty new to gardening and I recently (~2 weeks ago) got a Pinus sylvestris 'Fastigiata' plant and I noticed that some needles started to yellow. Here are a few pics:- The yellowing is mostly on ...
5
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0answers
41 views

Cucumber disease/ pest identification

Can anyone tell me what is happening with this cucumber plant?
5
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0answers
131 views

What is wrong with my Hydrangeas

My hydrangeas were looking beautiful until a couple weeks ago. Then I started noticing that some of their leaves had these gray powdery looing spots on them, their blooms started having brown spots ...
5
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0answers
547 views

What disease is affecting my Dypsis lutescens?

I received this Dypsis lutescens (palm) plant as a gift last spring, it had only two leaves and it was potted in nursery soil with sand. Recently I have noticed that the outer leaf started to form a ...
5
votes
1answer
2k views

What is happening to our potato plants? (going black, wilting)

We have a row of 3 different heirloom potato varieties, 50 originally, of which we've lost about 15 to a problem we'd like to identify. The following photos show the start of the issue, through to a ...
5
votes
1answer
116 views

What is the powdery mildew and why are my cucumbers not growing beyond 1 inch?

I have a healthy cucumber plant to all appearances. There is some powdery mildew which I am trying to contain with a spray for that disease. However, I have lots of buds which turn into tiny ...
4
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0answers
28 views

What's wrong with my fairy castle cactus?

My cactus used to be really thick and dark green but now it's so much skinnier and starting to shrivel up. Some of the arms are turning a dusty kind of brown and they're all leaning away from the stem ...
4
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0answers
15 views

How to get rid of the White fly

I noticed I got once again the white fly in my herbs and vegetables. I tried to get rid of it by planting Basil close to them, and it worked for some time but now is back again. I heard trying vinegar ...
4
votes
1answer
83 views

What are these white things on new leaves?

I have roselle planted. But I see these on the leaves. What are these? Edit: Added closeups
4
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1answer
1k views

Hibiscus buds turning brown before opening

My Hibiscus is loaded with buds, however they turn dark brown and never open. The leaves did have some signs of disease but we have sprayed the plant and it is looking better, however the buds are ...
4
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0answers
61 views

What is this foliar/fruit disease on our pear trees?

This year both of our pear trees (especially our dwarf Bartlett) have a new foliar disease that I've never seen before. It looks a lot like edema with the bumps, but with a lot more discoloration and ...
4
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0answers
782 views

What are these barely visible white spots and brown edges on my citrus plant?

I have a citrus plant and something else growing in a pot. The something else had some barely visible white mold-like spots for a few months, and now its and the nearby citrus plant's leaves are ...
4
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0answers
247 views

Globe Willow keeps going into shock

I live in Northern Arizona and globe willows do really well around here. However, I am having the opposite problem. Mine has went into shock twice this year. The first time I trimmed the dead branches ...
3
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0answers
21 views

What are these gall like growths on my spuds?

I noticed a volunteer potato plant in the garden a month or so ago which I thought was cool. It's just now at the tail end of winter in the southern hemisphere. Today I noticed that it had gall like ...
3
votes
3answers
52 views

What is damaging my tree Aloe?

I've had a Aloe plant for many years, mostly indoors. I finally repotted it a couple of months ago and split most of the pups off. All of the plants seem to have some sort of disease since then, ...
3
votes
2answers
110 views

Lilac Tree Branches Suddenly Dying

I have a Japanese Lilac Tree that was fine 2 weeks ago now there is 2 dead branches and 1 that is starting to die. They are not isolated and are random, with the first near the base of the canopy one ...
3
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0answers
18 views

Squash vine stopped growing?

I've seen this on several squash plants, where the vine seems to stop growing but the growth tip is still trying to produce fruit. Not sure what this is called - internode shortening or something? ...
3
votes
1answer
81 views

Young mango tree leaves get blackish and fall off

I have planted a mango seed and it was growing fine until a few days ago I noticed that one of the leaves had started going blackish. When I touched it, it fell. Yesterday I noticed that another one ...
3
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0answers
64 views

What wrong with my cactus

Ive had this cactus which i think is a Pachycereus Schotti/Monstrosus since years and its been growing fabulous. Ive just recently noticed it acquired some brown scales (non Insect) and looks like ...
3
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0answers
56 views

No leaves on tree tops. What’s wrong?

I’ve got two trees that didn’t get leaves on their tops. Should I be concerned? One is a twisted baby locust and the other is a scarlet oak tree. It did get really warm here and then freeze in the ...
3
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0answers
181 views

How to diagnose brown spots on dogwood leaves

We have a pink dogwood that was planted two years ago. Its leaves all have brown spots, and some leaves are quite covered with brown. It is more pronounced this year than last year. From research ...
3
votes
1answer
218 views

Pale green areas in new leaves of Draceana fragrans, disease?

Does anyone know whats wrong with my draceana? All the new leaves have those "pale green" areas, they have it already in the beginning. I´m familiar with the common pests and they are not the cause. ...
3
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0answers
54 views

What is wrong with my hibiscus?

enter image description here The growth on this little tree seems much slower than it's sibling. The leaves appear to be growing very misshapen and start to curl under. It's almost as if it's being ...
3
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0answers
162 views

What are these spots on my new bamboo palm?

Hi all! I’m new to gardening and want to know what’s going on with this palm I just bought from the Home Depot. There are white spots near the roots that look like fungus to me, brown spots higher up ...
3
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0answers
39 views

Buxus sempervirens - Deformed leaves

Can anyone help me? Suddenly my Buxus sempervirens appeared with the new shoots with deformed leaves. I'm in zone 9. It has not been cold though, and yes, it's a lot humidity every night.
3
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0answers
48 views

Why aren't my year-old apple seedlings thriving?

I planted a variety of seeds from apples from a local orchard. They have been growing for almost a year. They are about 8" and have suffered aphids and a white powdery fungus. I have sprayed plants ...
3
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0answers
604 views

Why are my potted outdoor Plumeria leaves turning yellow and brown?

All the leaves are yellow, with red around the edges and then eventually start turning brown?
3
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0answers
76 views

Black spot on leaf of cardboard cycad (zamia furfuracea)

I live in Korea. I think that my precious cardboard cycad has some problem. Where the plant came from? I purchased cardboard cycad on the internet. It was delivered in 36hr. When it was delivered, ...
3
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0answers
38 views

Pineapple leaf discoloration?

Can some tell me what’s going on with my plant? I have not done anything different and this started when we moved it inside.
3
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0answers
20 views

Magnolia not flowering well

My Magnolia ‘Vulcan’ flowers are not looking right. Attached photos are all new growth (in Australia, just entering Spring). Any thoughts as to the issue?
3
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0answers
193 views

Can someone identify Desert Rose Leaf problem?

I bought this Desert Rose from a big box store on clearance about a month ago. The leaves had this trailing/patchy lighter discoloration on the leaves when I purchased. Thought I could re-pot it and ...
3
votes
0answers
62 views

How come my majestic palm has patchy dried out spots?

This is an indoor pot plant. We have quite a bit of natural light thanks to a skylight, but not much direct sunlight unfortunately. The dry patches have been there for a while and I’ve tried various ...
3
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0answers
2k views

What are the white and black spots on the under side of my chilli leaves?

I am a newbie to gardening and was so chuffed to see my chilli (the plants are Chile guajilo and Chile chipotle) plants grow up. However, I have noticed leaves starting to fall. These leaves have, on ...
3
votes
0answers
39 views

How effective is a phosphonate treatment for phytophthora dieback?

I found on the Internet that the fungal disease phytophthora dieback can be treated with phosphonates. I am asking how effective this treatment is. If it's not very effective, is there any other ...
3
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0answers
879 views

What causes dark brown spots on guava fruit?

I am from India and I see that young guava fruits have dark black/brown spots on them. I grow them at my home. I have attached photos of the fruits. Could someone help in identifying the disease and ...
3
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0answers
274 views

Is this bay tree dying?

This tree has just recently got these marks on all the leaves and there's no new growth this year. I'm afraid it's dying but is there anything I can do?
3
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0answers
500 views

What is this substance that looks like red sap on my cucumbers?

I have this weird red sap on a few of my cucumbers. I was wondering if anyone has seen this before? These cucumbers were grown in our conservatory in the back garden (facing south) in pots, grown up ...
3
votes
1answer
198 views

What's wrong with my plants

I've recently bought Cestrum nocturnum from local nursery and transplant it in pot with 40% sand soil, 40% organic compost and 20% coco peat. But I don't know why its leafs are falling continuously. ...
2
votes
0answers
20 views

Unknown discoloration on tomato plant: how serious is this?

One of the tomato plants in our garden has discoloration both on the upper leaves and on one or two of the fruit, as here: How serious is this, and how should I address it? Is the plant salvageable? ...
2
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0answers
38 views

Can I save my lucky bamboo by replanting its leaves?

My lucky bamboo is turning yellow from the middle outwards, most likely because of microbes which entered through a wound. I have already cut off a small green top of the bamboo, disinfected the wound ...
2
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0answers
48 views

What's this white stuff on my petunias?

Any idea what is happening here and how do I fix it???
2
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0answers
23 views

What are these yellow spots on my Melocactus concinnus?

I purchased this Melocactus concinnus online a couple of months ago. I don't remember seeing those yellow spots on the bottom half of the cactus. It's possible, however, that I just didn't pay close ...
2
votes
0answers
21 views

What is this disease on my Christmas Palm, and how do I treat it?

I bought this Christmas Palm 10 weeks ago, and it was healthy and full, with no signs of disease. I'm in Ft. Lauderdale, zone 10. I placed the palm on my sometimes windy, south-facing balcony. I ...
2
votes
0answers
66 views

White coating on bottom side of pepper leaves

I just noticed this white coating on the bottom side of a few leaves of my pepper plant. I can not wipe it off. Is this some kind of fungal disease or some pest? Edit: I made some more images using a ...
2
votes
0answers
69 views

Avocado plant white resin/wax like substance on back of leaves. What could it be?

I planted an avocado plant from seed about 2,5 years ago. The plant seemed to grow well, but I moved it alot, due to unproper conditions (lighting, temperature). For the last year, though, it stayed ...
2
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0answers
35 views

Purplish discoloration on the leaves of solanum torvum

Recently my Solanum torvum started developing purplish discoloration on the leaves It is visible primarily on the top surface of the leaf, and lower, older leaves are more affected than the top ones. ...
2
votes
0answers
35 views

Why is my passion fruit's leaves are yellow? Is it dying?

I've bought a plant of passion fruit. Recently I've changed the ground of it. Several days ago the leaves began to be yellow and curled up. The photos are below. Could you please give an advise how ...
2
votes
1answer
47 views

Gardening. Potted cucumber plants

My potted cucumber plants appear to have mosaic virus. How is an insect barrier created?
2
votes
0answers
37 views

Disease on Thuja Occidentalis

In our garden there are two northern white-cedars (thuja occidentalis) that have gotten a strange light-greenish area on the base of their stem (see the image enclosed). The infected species are in ...
2
votes
0answers
88 views

Do these watermelon plants show signs of mosaic virus?

I salvaged and planted three watermelon seedlings a few weeks ago after my, somewhat flimsy, greenhouse blew over in a wind storm. The seedlings seemed to be thriving in their new homes, but this past ...