What am I doing wrong?

MarinaRussian · June 21, 2012

I have noticed on several tomato plants, that some fruits set and then they won't enlarge. They're just stuck at the "tiny lump" stage. What could be causing this and what can I do to make these babies grow?

zipcode · June 21, 2012

The plants are too weak. They do not have enough leaves to feed all the tomatoes, or maybe not enough fertilizer, water, whoknowswhat . The ones at the end of the trusses will just stay like that for a month or 2 until others ripen, and then start to grow. I always have this on the first trusses which are disproportionate in number of flowers (15-25 for medium or large tomatoes).

amideutch · June 21, 2012

Marina, a little more information on how you are growing and what you are growing your plants in might help in determing your problem. Ami

MarinaRussian · June 21, 2012

My tomatoes are in a greenhouse. They were planted on May 15th, I put about 1/2 a cup of last year's rabbit manure in each hole and I haven't fertilized them since. I water the plants once a week. Have sprayed them twice this month with a copper fungicide. I removed the lower leaves and pruning heavily, leaving mostly 2 stems, some 3 stems.

Until last week our weather was awful. Cold night temps (8-10C) and heavy rain every day. Now it's about 28C during the day and 15C at nightime. I leave the GH open for the night, otherwise it gets too humid inside.

feldon30 · June 21, 2012

Is there enough airflow in your greenhouse, or are you using fans to circulate the air? Otherwise, you may have incomplete pollination of the tomatoes.

You may want to use an electric toothbrush to touch the stems near each flower to encourage self-pollination.

MarinaRussian · June 22, 2012

Feldon, I have 2 doors open at both ends of the GH all of the time. The plants by the entrance get the most breeze and they're still acting up.

feldon30 · June 22, 2012

Then I'm going to chock it up to the cold temperatures you have had recently. Hopefully the next cycle of flowers will pollinate.

amideutch · June 22, 2012

Marina, when the sun is out during the day leave the doors open. In the evening close the doors especially if you are having cool nights. Once the temperatures have stabilized then leave the door open all the time. Ami

bower · June 22, 2012

Marina, I had exactly the same problem earlier this season. Several plants had set lots of little 'fruit buds' but they didn't grow. This also happened last year on Black Cherry, and never did turn into fruit - on Black Sea Man, the small ones started growing when the first ripe fruit were removed. I decided to try some nutrition - first a spoonful of molasses dissolved in a gallon of water for extra potassium (I put a cup of bone meal in each planting hole at transplant, so potassium is the nutrient most likely to be short.) Then I gave each plant a couple of scoops of compost as a top dressing.

I also did a bit of pruning, pinching the suckers and topping the plants that were getting too tall. This is supposed to encourage the plant to put energy into maturing the fruit already set.

Finally the sun came out, after two weeks of very cold wet weather (I am growing in a greenhouse, like you, in a cold wet climate). And indeed those little fruit began to grow, much to my relief! So it was not a pollination issue for most of the plants, but a shortage of resources. I also noticed that the different varieties responded a bit differently - nutrient boost was enough for some, others needed sunshine and higher temperatures as well. Anna Russian, especially, had beautiful big clusters of flowers that just turned into empty nests... until the sun came out. Now she's loaded with growing fruit.

I also read that providing support for the fruit encourages them to grow, so I am doing that as well now, making sure a support is present as soon as fruit starts to set.

The one that is doing poorly and setting only a few fruit in spite of the treatments is Vorlon, and there are signs this is really a pollination issue, maybe due to the humid conditions which it doesn't tolerate as well. A couple of the fruit are clearly lopsided, which shows it was only partly pollinated. A number of the little 'fruit buds' have also turned brown - a sure sign they're done for, not just waiting to grow. I think I should try hand pollinating this one instead...

MarinaRussian · June 24, 2012

Ami and Feldon, you're probably right about the cold temp, I close the door for the night, now.

Bower, so you actually now what I'm talking about. Now that I think about it, there might be a potassium deficiency, as well. I usually add ashes into the planting holes, which contains a lot of potassium, but this year I didn't have enough for all my plants. I used a P-50-K-32 foliar fertilizer a couple of days ago. This fertilizer is supposed to boost blooming and fruit set. Potassium Sulphate is next on my list.

Will let you know if all of this works, maybe this info will help someone else with the same problem.

June 21, 2012	#1
MarinaRussian Tomatovillian™ Join Date: Dec 2011 Location: Russia Posts: 176	What am I doing wrong? I have noticed on several tomato plants, that some fruits set and then they won't enlarge. They're just stuck at the "tiny lump" stage. What could be causing this and what can I do to make these babies grow? Last edited by MarinaRussian; June 21, 2012 at 03:06 AM.

June 21, 2012	#3
amideutch Tomatovillian™ Join Date: Feb 2006 Location: Germany 49°26"N 07°36"E Posts: 5,041	Marina, a little more information on how you are growing and what you are growing your plants in might help in determing your problem. Ami __________________ Life's journey is not to arrive at the grave safely in a well preserved body, but rather to skid in sideways, totally worn out, shouting ‘...Holy Crap .....What a ride!'

June 21, 2012	#5
feldon30 Tomatovillian™ Join Date: May 2006 Location: Rock Hill, SC Posts: 5,346	Is there enough airflow in your greenhouse, or are you using fans to circulate the air? Otherwise, you may have incomplete pollination of the tomatoes. You may want to use an electric toothbrush to touch the stems near each flower to encourage self-pollination. __________________ [SIZE="3"]I've relaunched my gardening website -- [B]TheUnconventionalTomato.com[/B][/SIZE] * [I][SIZE="1"]*I'm not allowed to post weblinks so you'll have to copy-paste it manually.[/SIZE][/I]

June 22, 2012	#7
feldon30 Tomatovillian™ Join Date: May 2006 Location: Rock Hill, SC Posts: 5,346	Then I'm going to chock it up to the cold temperatures you have had recently. Hopefully the next cycle of flowers will pollinate. __________________ [SIZE="3"]I've relaunched my gardening website -- [B]TheUnconventionalTomato.com[/B][/SIZE] * [I][SIZE="1"]*I'm not allowed to post weblinks so you'll have to copy-paste it manually.[/SIZE][/I]

June 22, 2012	#8
amideutch Tomatovillian™ Join Date: Feb 2006 Location: Germany 49°26"N 07°36"E Posts: 5,041	Marina, when the sun is out during the day leave the doors open. In the evening close the doors especially if you are having cool nights. Once the temperatures have stabilized then leave the door open all the time. Ami __________________ Life's journey is not to arrive at the grave safely in a well preserved body, but rather to skid in sideways, totally worn out, shouting ‘...Holy Crap .....What a ride!'

June 21, 2012	#2
zipcode Tomatovillian™ Join Date: Jun 2010 Location: Romania/Germany , z 4-6 Posts: 1,582	The plants are too weak. They do not have enough leaves to feed all the tomatoes, or maybe not enough fertilizer, water, whoknowswhat . The ones at the end of the trusses will just stay like that for a month or 2 until others ripen, and then start to grow. I always have this on the first trusses which are disproportionate in number of flowers (15-25 for medium or large tomatoes).

June 22, 2012	#9
bower Tomatovillian™ Join Date: Feb 2012 Location: Newfoundland, Canada Posts: 6,794	Marina, I had exactly the same problem earlier this season. Several plants had set lots of little 'fruit buds' but they didn't grow. This also happened last year on Black Cherry, and never did turn into fruit - on Black Sea Man, the small ones started growing when the first ripe fruit were removed. I decided to try some nutrition - first a spoonful of molasses dissolved in a gallon of water for extra potassium (I put a cup of bone meal in each planting hole at transplant, so potassium is the nutrient most likely to be short.) Then I gave each plant a couple of scoops of compost as a top dressing. I also did a bit of pruning, pinching the suckers and topping the plants that were getting too tall. This is supposed to encourage the plant to put energy into maturing the fruit already set. Finally the sun came out, after two weeks of very cold wet weather (I am growing in a greenhouse, like you, in a cold wet climate). And indeed those little fruit began to grow, much to my relief! So it was not a pollination issue for most of the plants, but a shortage of resources. I also noticed that the different varieties responded a bit differently - nutrient boost was enough for some, others needed sunshine and higher temperatures as well. Anna Russian, especially, had beautiful big clusters of flowers that just turned into empty nests... until the sun came out. Now she's loaded with growing fruit. I also read that providing support for the fruit encourages them to grow, so I am doing that as well now, making sure a support is present as soon as fruit starts to set. The one that is doing poorly and setting only a few fruit in spite of the treatments is Vorlon, and there are signs this is really a pollination issue, maybe due to the humid conditions which it doesn't tolerate as well. A couple of the fruit are clearly lopsided, which shows it was only partly pollinated. A number of the little 'fruit buds' have also turned brown - a sure sign they're done for, not just waiting to grow. I think I should try hand pollinating this one instead...

June 24, 2012	#10
MarinaRussian Tomatovillian™ Join Date: Dec 2011 Location: Russia Posts: 176	Ami and Feldon, you're probably right about the cold temp, I close the door for the night, now. Bower, so you actually now what I'm talking about. Now that I think about it, there might be a potassium deficiency, as well. I usually add ashes into the planting holes, which contains a lot of potassium, but this year I didn't have enough for all my plants. I used a P-50-K-32 foliar fertilizer a couple of days ago. This fertilizer is supposed to boost blooming and fruit set. Potassium Sulphate is next on my list. Will let you know if all of this works, maybe this info will help someone else with the same problem.