Why didn’t my tomato plants produce fruit this year?

August 12, 2020 9:34 AM

It’s mid-August and I’ve yet to see a single blossom on my tomato plants, so I think it’s safe to say that they’re not going to produce anything. What went wrong?

I’m growing two plants in containers on my balcony. I bought them as seedlings back in April, and they’re an indeterminate variety so I knew they weren’t ideal for container growing, but I went ahead anyway because I had limited options due to most nurseries being closed due to the pandemic.

The plants themselves seem to have flourished — they’re almost 4 feet tall at this point — but they haven’t blossomed at all. I fertilized with a bit of nitrogen fertilizer right after I planted them, but none since then. They’re near/under a large tree so only get a few hours of direct sunlight a day — could that be the issue? FWIW I have a friend who bought the same plants at the same time and hers also have not bloomed. Or is it possible they’re just a very very late-blooming variety? Unfortunately I don’t remember the variety and didn’t save any tags.

posted by mekily to Home & Garden (23 answers total)

We see this as well on the northwest WA coast. We think lack of bees or the right bees.
posted by Freedomboy at 9:36 AM on August 12, 2020

Best answer: If your plant isn't even blossoming, pollination is not the problem. I would suggest that there is insufficient light. I'd be looking for 6-8 hours of continuous/full sun, not "a few hours".
posted by saeculorum at 9:40 AM on August 12, 2020 [11 favorites]

I'm in eastern WA and am having the same issue this year. My plants normally flourish so I'm at a loss too. I'm just chalking it up to another curse of 2020.
posted by OkTwigs at 9:44 AM on August 12, 2020 [1 favorite]

Nitrogen is good for green growth and bad for blossoms/fruit. If the soil was already nitrogen-rich before you fertilized it, that may be the main problem.
posted by showbiz_liz at 9:48 AM on August 12, 2020 [9 favorites]

Best answer: I've had this problem with tomatoes and low light in the past. If they get enough water and fertiliser they don't get terribly upset about pot size - I've read about various semi-hydroponic ways you can grow tomatoes - but light seems to be critical.

A 4 foot run on an indeterminate plant is not actually all that big, which also rings true with light being your problem.
posted by How much is that froggie in the window at 9:49 AM on August 12, 2020 [2 favorites]

Best answer: Tomatoes need a fair amount of sun. Nitrogen encourages growth and makes plants green. For flowering you also need phosphorus. Try a fertilizer brand with a higher phosphorus level. Fertilizer packaging indicates its NPK - nitrogen (N), phosphorus (P) and potassium (K) - levels.
posted by shoesietart at 9:50 AM on August 12, 2020 [2 favorites]

Best answer: I vote lack of light as the issue. I have both a determinate and an indeterminate tomato plant growing in containers on my full sun balcony, and they’re both happy and fruiting. I had an extra indeterminate tomato seedling that found a home in a smaller container in the shade, and it’s about 1/3 the height and the first blossoms showed up 4-6 weeks later than the full sun one. I don’t think that one is going to fruit at all.
posted by A Blue Moon at 9:53 AM on August 12, 2020

You might also try trimming your indeterminate plants to discourage excessive leave and branch growth and encourage fruit development.
posted by shoesietart at 9:59 AM on August 12, 2020 [4 favorites]

Best answer: I'd guess it's either too much nitrogen or not enough light. Any variety of tomato, even a very late one, should have produced at least some flowers by now. If "a few hours" is less than 6, that's not a good spot for tomatoes.
posted by Redstart at 10:14 AM on August 12, 2020 [1 favorite]

Agreed on the trimming. I had two indeterminate seedlings bought at the same time and planted in the same raised bed. One flowered and fruited; the other grew very tall and was healthy and green but didn't do anything. I found information on trimming and within a week had tomatoes forming.
posted by BlueBear at 10:15 AM on August 12, 2020

nthing sunlight, but i'd also ask - has it been especially hot? if daytime temps stay consistently over 95 and night time over 75 they won't be happy or set fruit.
posted by squiddish at 10:58 AM on August 12, 2020 [1 favorite]

Is the growth leggy or bushy? If it's bushy, lack of light is not the problem.
posted by SaltySalticid at 10:59 AM on August 12, 2020 [2 favorites]

Also varieties matter. I bought three plants because the COVID situation meant I had to grab whatever was left on the shelf and that's all there was. They're all potted in the same potting soil, in the same excellent light conditions, and one of them - some sort of "purple" heirloom variety - is aggressively leafy but with almost no fruit at all.

also the San Marzanos are all rotten, turns out you can't do those in a pot at all. Thanks COVID for leaving me with crap tomato plants.
posted by fingersandtoes at 11:50 AM on August 12, 2020

I had exactly this problem a few years ago when I used a nitrogen-rich fertilizer. I omitted it the next year and had decent results. My site isn't the greatest for tomatoes, but the nitrogen fertilizer pushed it over into producing all kinds of foliage and no fruit whatsoever.
posted by tellumo at 12:00 PM on August 12, 2020 [2 favorites]

Best answer: Some random thoughts:
How often do you water? - They like a good soak at least once a day, I usually water mine in the evening.
Are the containers mulched to keep the moisture in?
Is your balcony windy (that can dry them out)?
How big are the containers?
Also (contrary to some advice) I find that they like to be crowded together.
And yes they need a lot of sunlight.
Do you have a photo or two?
posted by carter at 1:44 PM on August 12, 2020

The biggest problem in pots is often uneven watering. While the "not enough sun" comments above are probably right, it could also be because the plants are too wet, or too dry, or if they veer between the two. A well maintained tomato in a pot at this time of year- with enough sun, water and fertilizer- can easily be 8 or 10' tall even if the pot they are in is pretty small.

If you posted a few pictures it would be a lot easier to help you. One look and an experienced grower can tell you if it's a sun issue or a fertilizer issue. Water issues are harder to figure out.
posted by Patapsco Mike at 4:05 PM on August 12, 2020 [1 favorite]

I'm another note for temperature being a problem. Too cold or too hot can keep plants from producing.Total lack of flowers would make me think it's maybe been unusually hot in your area?
posted by WalkerWestridge at 4:05 PM on August 12, 2020 [1 favorite]

A few years ago I had a tomato on a 2nd floor south-facing balcony, so it was always really warm. No flowers appeared, and when I went on vacation in late August, I gave it to my friend who put the container in his yard. Then it finally made a bunch of delicious (I'm told) tomatoes.
posted by Standard Orange at 4:38 PM on August 12, 2020

You could try adding some potassium and phosphorus rich fertilizer and see if you can get some flowers going. And move them to a sunnier spot if you can. Otherwise, try again next year. (cherry tomatoes are often more forgiving of imperfect spaces/climates).
posted by kjs4 at 6:32 PM on August 12, 2020

How deep are your containers? Tomatoes can need some significant downward space for roots.
posted by bile and syntax at 7:17 AM on August 13, 2020

Best answer: I get tomatoes well into September, so don’t give up yet.

My theory is too much nitrogen exacerbated by not enough sunlight. Tomatoes need 6+ hours of direct sunlight a day to set fruit properly. Can you move them?
posted by lydhre at 12:16 PM on August 13, 2020

Best answer: Where are you? Which direction does your balcony face? I agree that too much nitrogen and too little sun can be a big part of the problem, but in addition to that tomatoes won't bloom if it's too hot or cold at night. If your balcony is primarily north (northern hemisphere) or east facing you don't get the benefit of reflected heat from nearby walls which can really help if nights are a bit too cold. Also soil temperatures need to remain above 65 degrees, which can be a problem for potted plants on a cool or windy balcony.
posted by oneirodynia at 10:56 PM on August 14, 2020

Response by poster: For everyone following along at home -- it was indeed the lack of direct sunlight! A few weeks ago I moved them to my back balcony which gets a bit more sun, and they've started to produce a few blossoms. Might be too late in the season to get any fruit, but we'll see! Thanks for all the help.
posted by mekily at 8:34 AM on September 9, 2020 [2 favorites]