A Gardeners Forum Forums General Discussion The Food Garden Forum The Tomato Forum Tomato flowers falling off the stem?

I have two tomato plants planted next to each other, a grape and a beefmaster. The grape tomato plant is full of flowers and healthy tomatoes. The beefmaster plant gets large flowers on healthy green stems, but the flowers close and then the flower stem turns yellow then brown and falls off leaving no tomato, this has happened with all of the flowers so far on this plant. Why aren't the flowers on the beefmaster staying healthy? Both plants are green and healthy and show no sign of disease anywhere.

Keith,
You have blossom drop. That is where the flower(bloom) doesn't pollinate. Causes can be several. The smaller cherry types tend to set better and have less of it. But this year I haven't had as great of a set on my cherries as normal. I will list a few of the more common causes in my opinion. Weather conditions are the biggest factor I find. High humidity causes clumping. High heat stops set on most larger types. Low insect activity and no wind can also be a cause. We usually have enough wind here but have low pollinating insect population. I can notice a difference when the wind doesn't blow. So I go by and shake the cages every morning and take something and either shake or brush the sprawlers good. This helps. When I said pollinating insects what I mean is insects that tend to stir the pollen up in some fashion. Whether it is the buzzing of their wings or brushing on it and stirring it up. They need to actually touch each part. Some people use a cordless toothbrush and go to each bloom and give it a little brushing. With 80 plants that would take a lot of time for me. If you plants are diseased which your aren't the blooms will turn yellow and die off before opening sometimes. Hope this helps some. Jay

I always thought tomatoes self pollinate? If I do need to pollinate, do I need to open the flower the day before it would normally open and rub it against another flower, or do I just let the flower open up on it's own and rub it against another flower? There are a good amount of flowers almost touching each other so not sure how they never pollinated?

Heat could be the next best possibility they do get a lot of direct sunlight.

Here's another thought. Check for aphids. Awash in a sea of tomato vines, you may not even notice or think that they're a problem, but even minor infestations (<12) on flower stems can kill the flowers. I've been doing some casual observation about this for about 3 years, and I can't for the life of me figure out why some tomato varieties are susceptible to this aphid damage, while the vines of other varieties-- mingled in-- are not.

Your description of the flower stems sounds exactly like what I noticed on my early girls today. They & the cherry tomatoes are climbing all over each other. Aphids on early girl flowers, none on cherry flowers.

Could be wrong but it's worth checking out.

I didn't make myself clear. Not the best at describing things. The best way I've heard it stated is that tomatoes are self fertile and self pollinate when conditions are ideal. If they aren't then for good bloom set they need a little help. I will attach a link that describes it fairly well. Jay

Keith,

In addition what Jay and Marica said, the other reason why blossoms fall off are related to temperatures [night below 55*F, day above 90*F] during the blossoming period or excess nitrogen fertilizer or your tomatoes are shaded.

Your tomato plant might benefit in fertilizer with a lower nitrogen content like Fish Emulsion [one teaspoon diluted in one gal. of water, or as per label directions]. Keep soil moderately moist. The tomato plants should be in full sun. Tapping the blossom stems during midday when the flowers are open may also help set fruits.