I think every gardener has lovingly checked on their plants only to find a weird brown spot or something looking 'off'. The first thing I usually do is spend 3 hours searching google only to find out that my beloved tomato plant is dying of some incurable, viral disease and is going to infect the rest of Washington State if I don't remove it from the garden in 10 minutes. Then I go out and order 5 different fungicides and a lifetime supply of Neem Oil.
I've personally 'diagnosed' the plants in my garden with every known virus or issue known to man, even if those don't actually exist in Washington State - it's just so easy to go down that path. I'd say 99% of the time it's really not going to be that worst case scenario, and the 1% of the time it is, it will be fairly obvious something is really wrong and it isn't just a few leaves or fruit abnormalities. In fact, out of the probably 500 tomato plants I've grown I've only discarded maybe a dozen due to disease concerns, most of the time early on (and probably not a real reason for concern), and I've only dug up 1 fully mature tomato plant due to disease. The rest I've been able to successfully manage through basic pruning.
It's actually pretty funny today that I cut back my mojito mint plant (sorry guys it might be a few weeks until the bar is back open), because it had a bunch of brown spots, was wilting, and some clear signs of pest damage. If it were one of my tomato or pepper plants I would have been panicking, but I know that it will find a way to survive and just trimmed it back half way and gave it a healthy dose of fertilizer. Mint is basically a weed, but so are tomatoes.
The goal of this blog is to share some of the pictures of issues my plants have had and survived (and yours probably will too), and ones where they didn't. I have no education or training in identifying plant illnesses, but I can share my ideas as to what it may or may not be and give you hope that your plants will probably be just fine too 😊
First let's start out with things your plants will survive 🥳
Blossom End Rot
This one looks scarier than it is, but it is just a disappointment more than anything. There is nothing terminally wrong with your plant, but it does need either more (or consistent) water or more calcium - for me it is usually the former. I've also noticed that sometimes the first tomato or two of the season for the plant (for whatever reason) has blossom end rot and the rest are fine after that 🤷♀. I mentioned this in an earlier blog post, but I've had a hell of a time with San Marzano, and plum tomatoes in general, with blossom end rot. I feel like I tried everything, and it still impacts probably 1/3 of the fruit. A lot of other people have had similar experiences, maybe its the weather here? Or maybe we are just too neglectful? Anyways, find tomatoes that work for you, your environment, and your lifestyle. If you find these on your plant just cut off the impacted fruit and discard as soon as you notice it - no point in letting the plant use its precious energy to continue growing and ripening fruit with blossom end rot. Then try either watering it more consistently or applying more calcium (like CalMag)
Above: blossom end rot on a few Garden Peach tomatoes. This tomato is in a 10 gal container and I noticed one day it 'drooping' during in the afternoon - watering inconsistency is likely the culprit here, but I treated it with some CalMag just in case
Early Blight
This is a pretty common disease and usually occurs in cold, wet/humid weather. This year I have a couple of tomatoes that seem to be showing symptoms of this. To avoid spreading this disease you should avoid overhead watering (all of these are watered through soaker hoses) and practice crop rotation (which I don't always do a good job of). You can also spray with copper fungicide to help prevent this disease from taking hold in your garden. This can be fatal if it attacks your seedlings or the bottom stem, but I find it is usually just limited to foliage.
So what do you do if your plant is already showing signs? If it's on the foliage, you can just prune off any infected leaves and discard them in the trash. I also recommend keeping no foliage in the bottom 6-12 inches of the plant. You can also spray your plant with neem oil or do a neem oil soak - this may reduce further spread. Keep a close an eye on the plant, and if even after careful pruning and neem application it is spreading significantly, then I would just go ahead and pull the plant. The following year you may want to consider rotating some plants outside of the nightshade family into that location.
Flea Beetles
This is my #1 garden issue (besides deer of course), but your tomatoes will survive it. It all started for me last year, when I began to notice some tiny holes on the lower tomato leaves on a couple of my plants. It quickly escalated to many tiny holes on almost of my plants. I sprayed neem oil like it was my job, scattered diatomaceous earth so it looked like it was snowing around the plants, and almost no change. They just kept coming. This fall and spring I completely turned over all of the soil in my raised beds and pots and cleared all leaves and debris within the garden area (plus spent a lot of time googling what to do). And then June rolls around, and more tiny holes and flea beetles. This year I gave up a little, and have been spraying neem oil and removed all foliage about 1 ft up from the ground, but they are pretty crafty and agile pests. Fortunately, they are more of just a nuisance to see and don't materially impact the tomato plants (remember tomato plants are weeds and will find a way to survive). They can though spread disease, which should be your biggest concern if you have other tomatoes in the garden exhibiting signs of a disease - which makes it that more important to remove any diseased plants.
Being eaten by a deer Good job keeping the deer fed! Don't you feel warm and fuzzy inside about giving back to nature?! Kidding - this sucks. Ideas for stopping them: put up a fence, use deer spray (this only really works for so long), add netting around your plants, get motion sensing sprinklers, or get a dog that likes to chase deer. I recommend always picking your fruit right as soon as it starts to ripen - as soon as you see a color - get it before it is gone. There is some debate on whether or not fruit that is allowed to fully ripen on the vine tastes better than fruit that is picked before it is fully ripened, but obviously those people don't have deer and I'd rather have fruit than nothing at all.
Unfortunately, if a deer eats the top off the plant itself while it is still a seedling, it may be easier to just replace the plant if it is early in the growing season. I had the deer top off 3 tomato plants this year in early July (mid-maturity) and decided to leave them in, and they have since regrown and are putting out fruit. So while the plant will most likely survive if the stem is attacked, it may make more sense to just replace it if it is early enough.
Being eaten by a caterpillar
You can pick off caterpillars as you see them and discard of them somewhere away from your precious plants. I don't have a great picture of a caterpillar hole in a tomato saved, but will be sure to post one once I do. I no doubt will have at least one this year. They make almost a perfectly circular hole through your tomato, it is hard to confuse it with another critter.
Being eaten by a rodent or squirrel
Good luck keeping these buggers out! Luckily they aren't as devastating to crops as deer are, but they have a tendency to just take a bit out and ruin it before moving onto their next bite. Super infuriating! You can see in this picture they took a few bites to test for ripeness, and left a strawberry top nearby. Obviously the tomato's ripeness wasn't up to their standards so they moved on 😭
Nutrient Deficiency
This one is a bit tough to identify what the cause actually is. Could be nutrient deficiency caused by over/under watering, having too much of a nutrient, over/under fertilizing, etc. Usually if I see this I think through how frequently and recently I've fertilized them and which fertilizer I used, depending on how much time has passed I may reapply fertilizer or just leave it be. I have found it much more difficult to manage nutrients in containers than in the ground. So if you have the space, it will probably save you some headache to just plant the tomatoes in the ground.
Things you should maybe worry about😓
Tomato Spotted Wilt Virus
This was a wild one and nothing I'd seen before. I had a Paul Robeson plant begin showing these circular shapes on the fruit itself and ripening really oddly. There were large blotches and circles of unripe tomato on each fruit - even when left to ripen for extended periods of time. I eventually pulled the plant and tossed it and the fruit. Sadly, I didn't take as many pictures as I should have, but below you can kind of see the spotting on one of the first ones I harvested. The others had significantly more spotting than this one, and it killed my soul to throw away dozens of fully formed beefsteaks and to throw away a fully mature plant, but it is better to sacrifice one than your entire crop.
Sorry in advance for the early 2000's pixelation 😂
Stem Cankers
I'm not sure if this is Alternaria Stem Canker, Early Blight, or if they are something else entirely. The top 3 pictures are from 2022 and are tomato seedlings prior to transplant; I believe one was Azoychka and the other Black Sea Man (both heirlooms). The spring was exceptionally cold and rainy, and all of starts really struggled when they moved outside, even though they were in a covered greenhouse. These 2 plants were the only ones out of ~30 I had that exhibited these symptoms and the rest were healthy and happy the remainder of the season. I discarded these two after noticing the cankers and seeing them extend.
The bottom 3 pictures are from a German Gold tomato that is fully mature and has full-sized fruit. The canker extended from the main stem to a branch and I removed the branch which is pictured below. The plant isn't showing any signs of wilting at this time, and I sprayed the canker with neem oil to see if it will reduce it from expanding further. What is interesting, is that it hadn't rained for a month prior to this canker becoming visible and the bed is watered via soaker hoses, so it is not clear how it would have spread to this part of the stem - unless maybe it is the dew? It is really difficult mentally to remove a mature plant this late in the season, so I am giving it some time to see if the spreading stops and/or if there are any additional symptoms.
Late Blight
I haven't forgotten about you, Late Blight, I just don't have any pictures. This is a very common issue experience in the PacNW and is usually towards the end of the growing season. You will often see water soaked lesions on the foliage and the browning/blackening of stems. I'd go ahead and just harvest whatever is remaining and discard the plant. Fortunately, as long as you correctly dispose of the plant this shouldn't overwinter in your garden.
Conclusion
It can be nerve wrecking to see your tomato-child develop blemishes or show signs of disease, but most of the time it is nothing serious and can easily be managed through consistent watering, fertilizer application, and removing any yellow or blemished foliage. In the rare case something is truly wrong, you will likely notice multiple different symptoms and the plant itself will likely be struggling to thrive in comparison to the rest of your plants. I recommend monitoring the plant before you make to bold decision to remove it, but there comes a point in time you may need to sacrifice it for the good of the rest of the garden.
If you have pictures of concerning symptoms feel free to share and we can see if we can visually diagnose them together 😊
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