The first thing to do when you notice a not so healthy looking plant is to find out exactly what is going on, so that you can begin you search for the cure. Below is a list of symptoms together with possible causes to get you going on your quest to grow the best possible tomatoes. Try doing a Google image search once you get an idea of what your tomato plants are trying to tell you, and see if it looks like what you’re seeing on your own tomato plant leaves.

Discolored leaves

Yellow

As you can see below, a yellow coloring of your tomato plant leaves can be caused by many different things. The color yellow either covers the entire leaf, is limited to patches or limited to just spots, depending on the cause:

• A lack of nitrogen affects the lower leaves. It spreads to the upper leaves.
• A lack of calcium affects the upper leaves
• A lack of manganese is rare, but will result in dead patches on the leaves, ringed in yellow
• Wilt diseases can cause a shortage of nutrients, which will then result in a discoloring of leaves
• Fusarium Wilt affects older leaves
• Verticillium (Verticillium dahliae)
• Leaf spots (Early Blight or Target Spot)
• Root rot
• Mosaic virus results in mottling
• Aphids
• Spider-mites can cause a white-yellow speckling

Light green

• Too much nitrogen
• A lack of manganese

White

• A lack of iron
• Powdery Mildew results in powdery patches

Black

• Fusarium Crown Rot

Curling leaves

• A lack of potassium affects older leaves
• A lack of iron
• A lack of copper is rare, but results in blue-green flappy leaves
• Curly Top virus affects upper leaves and results in a purple-like color

Spots on leaves

Brown

• Early Blight or Target Spot (Alternaria solani)
• Late Blight (Phytophthora infestans)

Dark

• Bacterial Speck (Pseudomonas syringae)
• Bacterial Spot (Xanthomonas campestris pv vesicatoria)

Purple

• Late Blight (Phytophthora infestans)
• Tomato Spotted Wilt/Impatiens Necrotic Spot Tospoviruses

Wilting leaves

• Fusarium (Fusarium oxysporum f.sp. lycopersici)
• Fusarium Wilt
• Fusarium Crown Rot
• Verticillium (Verticillium dahliae) can result in wilting at midday but recovery at night
• Bacterial wilt (Ralstonia solanacearum)
• Root rot
• Tomato Spotted Wilt/Impatiens Necrotic Spot Tospoviruses (TSWV or INSV)
• Nematodes causes the plant to wilt prematurely
• Walnut toxicity if the plants grow near a walnut tree

Drooping leaves

• Fusarium (Fusarium oxysporum f.sp. lycopersici)
• Fusarium Wilt
• Fusarium Crown Rot

Flies on leaves

• Whitefly (1 mm), more often seen in a greenhouse than out in the open
• Thrips (1 mm), onion thrips (Thrips tabaci) and flower thrips (Thrips obscuratus)
• Fruit fly

Removing some of the leaves

If the problem is that you have too many tomato plant leaves then here are some tips on removing some of the leaves to provide the plants with more sunlight and oxygen:

• Single vine variety: All ‘suckers’ can be removed and staking should first be done after the first flowers appear to create a strong plant.
• Multi-stemmed variety: All stems should have the same size. Any side stems below the first flower cluster can be removed to create a strong main stem.
• Determinate variety: ‘Suckers’ below the first flower cluster can be removed.
• Sterilize knife or scissors between plants, or use your fingers to pinch of unwanted leaves and branches
• Remove branches during dry days to avoid bacteria getting into the ‘wound’ because of rain
• Remove sick leaves and branches to reduce spreading of diseases
• You can reuse any clippings – they will grow into new plants if you stick them into the soil!

Cucumber leaves

I haven’t been able to find any evidence saying that tomato plants can’t rub leaves with cucumbers. I think it’s a myth and more a question about space. Cucumbers grow big leaves, and they could overshadow a tomato plant if the plants were standing close.

While it should be safe to grow cucumbers near tomatoes, there are some plants that are even recommended companion plants for tomatoes, like French marigolds (Tagetes patula), because they deter nematodes. Other plants that act as pest control are:

• Basil
• Chives
• Parsley
• Onions

Source:

How to Grow Juicy Tasty Tomatoes by Lucia Grimmer and Annette Welsford

You can propagate strawberries by dividing old plants or by taking care of the runners sent out by old plants. If you pinch off the flowers of a selected few old plants you’ll encourage more and stronger runners:

With a 10 cm (4 inch) pot buried beneath a runner it will soon send roots into the pot:

Provided with good potting soil the new strawberry plant will be off to a good start and it’ll be easy to replant since the roots will be intact when you remove the pot and replant elsewhere without the pot.

Cut the stem from the mother plant and replant at 40 cm (16 inches) between plants and 75 cm (30 inches) between rows. These new plants will provide you with healthy strawberries for three seasons before the yield drops and the bed should be replanted, preferably with another type of crop to avoid a build-up of diseases.

After each season most of the foliage should be removed to make room for berries next year. In the picture below in the bottom, three plants have been pruned and the original foliage mess is shown to the right:

Light and air can now reach the plants which in return will provide you with plenty of healthy strawberries in the coming season.

Luckily it seems that the leaves affected with blight just dries up and breaks off and don’t cause damage to the main stem of the tomato plant:

I removed the affected foliage and tomatoes and the plants are beginning to look healthy again:

Time will tell if they’ll survive long enough to produce mature tomatoes. As you can see in the picture above there are not many leaves left to do the work.

… which is exactly the problem with my broccoli and cauliflowers too – them caterpillars hungry!:

What I should have done was to grow these plants in a tunnel so that the mother of these caterpillars couldn’t have laid her eggs on the plants when they were small.

Oh well – I’m actually proud that the plants grew this big. Besides the damage done by caterpillars the plants look really healthy. Next year I’ll build a tunnel. And oh – we actually did harvest one broccoli, a real nice one too.

I have tried to rescue the rest of my corn plants that are still standing with poles hammered into the ground as a support structure:

As usual, the lazy man’s way to solve trellis problems in the garden – cable binders :

A better solution would have been using old seat belt – or even better: Protection against the wind.

My bean trellis was not strong enough either, as it collapsed when the pressure from the wind increased:

It’s difficult to imagine that this was once a bean trellis but check out this post to see the original structure: Building a Better Bean Trellis

Somehow I managed to rescue the trellis and you might even be able to find some beans in the picture:

Fortunately my tomato plants are well protected against the wind because they are close to the concrete wall, but then they were hit by blight – nobody said this would be easy . I have tried to do some damage control by removing most of the affected leaves and fruits. Now there’s not much foliage left to do the work but hopefully the plants will be able to cope anyway.

They remind me of my old tomato plants in my old garden. I didn’t prune them because of blight though, but because I wanted the sun to be able to reach the tomatoes. Now I’m not sure what’s more important – foliage or direct sunlight. I just know what we all want: Tasty juicy tomatoes, blight or not.

They’ll quickly grow too big for my garden. Maybe if I only had one tree it would fit in the garden, but since they have always been pruned the limited area was never a problem. Last year I pruned them really hard and removed all shoots so only the bare stems were left (thicker than 5 cm / 2 inch in diameter). That resulted in not a single apple being produced. Bad idea.

So this fall I’m leaving a single shoot per stem, hoping that apples will develop on those shoots next year, where they’ll be one year old:

I guess the lesson is that apples won’t develop on wood younger than 1 year.

The ideal situation for me would be to plant an apple tree in a place with lots of space around it, and then forget about it until I would go out and collect the apples. And then let it grow according to its own genes and chop it down once it stopped producing apples.

When you start pruning hard it’s like you can’t go back to free growth without letting the tree grow into a big mess. So I have to live with the decision of the former owners and learn how to prune properly, as I don’t want to chop the trees down, since that would force me to go to the supermarket instead.

I have five old apple trees in my backyard which are quite old. I would estimate the oldest to be about 25 years old, and it has a trunk diameter of 30 cm (12 inch):

The problem I have with these old trees is that they grow like crazy. They have really dug in through the years. I was told that the former owners of the property would cut away any shoots each year, but I had hoped that I could avoid this work, since I don’t like cutting trees.

Last year they just got too big for my backyard garden, so I cut the trees back to where they were used to be before I moved in. That left me with a lot of twigs but the garden looked nice again.

Then the trees start growing like crazy this spring, putting up 50 cm (20 inch) shoots (see the first picture) and worst of all – not a single flower or apple So no apples on this years shoots.

They have used all their energy for growth and nothing for reproduction (apples). So I guess I’ll select about 10 shoots on each tree and cut away the rest to see if they’ll produce apples next year. Last year I picked 19 kg (42 pounds) for eating, and the birds got much more out of it.

The party is clearly on the 1 year old top shoots, and not much is going on below on the older wood:

The numbers on the picture below is the age of the wood:

But what the heck – I bet the fruit is just as good if we can get to it before the birds.

And here was another one:

It was weird since the weather was beautiful and had been so for days. So I looked up thinking the gutter must be full of water and leaking. But no, they sky was blue and the gutter is brand new:

I starred at the gutter for a couple of minutes, scratching my head, before I figured out what was going on. Don’t mind the expensive new powder coated metal gutter – the vine is freaking bleeding!:

Oh dear… Just wanted to prevent the vine from ripping down the gutter a couple of days earlier, so I just cut off the ends of the vine, which had been growing in under the gutter and the roof. Bad timing:

Other cuts on the vine had been done in time before the vine started sucking up water and distributing it:

And another correctly timed cut:

So remember to cut or prune your vine when the leaves fall off before winter, or you’ll end up with blood on your hands. Or water. (And where the hell does all that water come from, it’s so dry now?… anyway)

I have this bamboo growing like crazy on a south facing wall. I cut it down every year, but it keeps coming. I thought about removing it completely, but it turns out to be pretty useful:

I cut down all the shoots at the ground and cut them into smaller lengths. They’re perfect for marking your rows after sowing seeds, and for some reason they’ll  last several years. Bamboo sticks are quite expensive in our local supermarket, so I’ll leave the bamboo where it is for now.

Yes! The first tomatoes are finally ripe. They’re late because the ones I originally planted were cut down by killer slugs. That was a tough one since those original ones I sowed indoor where they germinated in my windowsill and grew up to become sound 20 cm (8 inch) plants. I’m not sure what to do to keep the killer slugs away from my small tomato plants next year, I’ll have to figure that out.

It was just before vacation I lost the original ones, but a friend looking after the garden in the meantime played a prank on me. He found some new plants at the supermarket which were even taller and planted them instead of the slaughtered ones. He didn’t say a word about it until weeks later after we got home from vacation, and I didn’t tell him that I knew what he did. But of course I knew, they were my small babies. So I don’t actually know what varieties I’m growing, the ones you see in the picture I would like to try to save seeds from tomatoes but I don’t think I’ll do it this year since I don’t know what they are. But they’re healthy and the taste is okay. We only tasted the variety on the left so far, the one on the right is a beef tomato.

There are not many leaves left on the plants, because I have worked from the principle that if any leaves are casting shadows on any of the fruits, the leaves have to go so that the sunshine can reach the fruits. I’ve also pinched any shoots appearing between the main stem and the side branches to keep the fruit production high. Those shoots will not produce much fruit. Next year I’ll try and limit the plants to having only one main stem per plant. They are sensitive to the wind as they are now, so I hope that they will be more stable with only one stem.

I’m using a growing bag which I’m sure is filled with all kinds of nutrients. It works well but in the long run I would like to use my own compost just to live a little more self-sufficient. Besides, I’ve read that tomatoes should be able to grow in almost anything, so I think it should be possible to do.

The self-watering box I use below the growing bag is very good at providing the soil with the right amount of water at all times. I’m considering buying two more and digging holes for them in the ground, so that they are out of sight. The cats are using the box like a scratching pole which is not a pretty sight and it won’t last long either.