Q.
Hi, my tomatoes have developed rot at the bottom of the fruit. My other plants appear to be okay. Can you please advise how to stop it affecting my tomatoes? Matt.
A.
The problem is blossom end rot which commonly affects tomatoes, capsicums and courgettes. It is not a disease but a physiological disorder and can't be spread from plant to plant or from fruit to fruit.
See below for causes of blossom end rot and ways to help prevent it:
- Irregular, uneven watering. Water plants consistently and regulate the watering depending upon the weather conditions.
- Tomatoes growing in containers (or planter bags) have more chance of drying out - one big water a day is preferable to two light waterings. Take care not to wet the foliage too much. Use SaturAid for container grown tomatoes to ensure that water is evenly distributed through the pot and the potting mix remains moist between waterings.
- Tomatoes planted early in the season when temperatures are cool are more susceptible to blossom end rot. Early fruit may show signs but later developing fruit should be fine.
- Tomatoes can also develop blossom end rot due to a lack of calcium and magnesium. Use a fertiliser low in Nitrogen (N) and high in phosphorus (P).
- As tomatoes grow very rapidly over a short period of time, make sure you feed them regularly, if using a liquid feed do it every fortnight.
- If you are growing tomatoes in a glasshouse increase the ventilation as high humidity can also contribute to blossom end rot.
Tui Organic Seaweed Plant Tonic is a seaweed based tonic which is great for tomatoes.
The good news is if you get the fertiliser regime right and water consistently the blossom end rot will go away. Remove and affected fruit to encourage more fruit on the plant.
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How do I treat blossom end rot on my tomatoes? Comments
Every year our potatoes get a brown scale, wart like on them. Wondering why? H
Carol Glidden
Hi Carol, this is a very common problem, it is most likely potato scab, often this problem can build up in the soil and if you have it each season and they are planted in the same spot the problem will keep coming back. It can be limited by adding lime to the soil, as it prefers acidic soil. Potato fertiliser will help balance the soil. Try rotating the spot where you grow them if you can. Thanks, Tui Team.
jenna
how to stop blossom End rot
dennis
I switched fertiliser to one that had calcium in it but it didn’t fix the problem. The variety I had grown in the ground successfully (Black Krim) just didn’t like being grown in pots - even very big pots. A hot summers day in NZ means uneven watering and this means blossom rot. In the end I switched varieties (to Mortgage Lifter) and so far no problems.
Jeff Sole
Hi Dennis, check out the answer above. All the best, Tui Team
jenna
Hay matt.with your tomatos with blossom end rot....use some lime...and work it into your soil under your plants then water it in.it works well.scott
Scott Abbott
Thanks for this timely answer. Some of my tomatoes are ripening now and some have the rot at the bottom.
Daphne Carvalho
mix a thick slurry of water & lime and pour around plant away from stem, water this in over a few days.
Ray
I have always grown tomatoes in pots and always had problems with blossom end rot. I now cover the top of the planter mix with a layer of wood pallets or wood pallets cat litter and they hold more moisture. I don't get blossom end for any more, it really works.
Les
Thanks for sharing your tip Les!
Tui Team
I had tomatoes rot but i asked some friends of mine and they gave me copper to spray on them and they told me to put some copper wire cut into short pieces put them through the steams as the it help kill it as my tomatoes are doing well.
robert king
I have had a miniature apricot tree for 6 years and it won't produce any fruit. Has had about 2 blossom flowers in the last couple of years.
Gail
I have had a miniature apricot tree for 6 years and it won't produce any fruit. Has had about 2 blossom flowers in the last couple of years.
The Tui Team
Hi Gail, dwarf apricot trees are better suited to warmer climates with some winter chilling, which initiates the flower buds for fruiting, they don't do well in areas with heavy frosts or areas of high rainfall, especially in early spring. The trees are self fertile, but would benefit from a pollinator planted close by. Apricots flower and fruit on the previous seasons wood, so if you are regularly pruning your tree you will be removing the fruiting wood. Spurs fruit for 3-4 years.
Why am I only producing male zucchini blooms again this year?
Engelina
Lianne
Hi Engelina, usually the first flowers on immature plants are all male as it takes less energy for the plant to produce male flowers, female flowers take more nutrients and energy for the plant to produce them. There are several factors that cause only male flowers, such as poor soil, make sure plenty of organic matter is dug into the soil before planting and that the soil is free draining. Infrequent watering, if the plant dries out it becomes stressed, it may only produce male flowers until watering is adjusted, avoid wetting the foliage as this leads to powdery mildew on the leaves which reduces plant vigour. Make sure the plant is in full sun and gets plenty of sunlight, as well as having good air circulation around the plant. Feed the plant with a balanced fertiliser such as Tui Tomato food or Tui Seaweed & Fish fertiliser, for flowering plants need potassium (or potash), so a fertiliser rich in potassium is beneficial. Mulch around the plant to help conserve soil moisture in the growing season and to keep weeds down. If you are experiencing extremely hot weather, the plant will be stressed and so may only produce male flowers. This could be the case if the plant is in a glasshouse or tunnel house where temperatures are high, make sure there is good ventilation.