[Geordie]

Never had a problem with splitting tomatoes before but this year nearly every one of my plants has some tomatoes that are splitting.

Anyone know why?

[spuriousmonkey]

Too much water.

Caused by rain??

Or else overwatering.

[Baldy]

That tends to be the cause... though I've found this year that my Red Pears have seemed particularly prone to splitting, Tigerella have a bit and my Orange Paruche not at all. Guess smaller cherry toms might be more robust against splitting - perhaps different varieties are more prone.

Cheers,
Balders

[gypsy]

Some varieties are more prone to splitting than other. It can be due to over watering or over feeding once they are nearly ripe. May also be due to hot days and cold nights.

[mumofstig]

It happens when they get a good watering after they've been a bit dry for a while. The sudden uptake of water causes the swelling that splits the skins.

It is what we have to put up with, unless we want to grow thick-skinned varieties like they sell in the shops 

[Markw]

Yes I lost loads of cherry toms due to the heavy rain last week It is just one of those things.

[JayG]

Some varieties are definitely much more prone to splitting than others - my Red Alert and Inca plum toms almost never split under any circumstances, whereas Sungold almost always do no matter how hard I try. Sweet Million are somewhere in between the two.

Strangely though, a spare Sungold plant grown in the garden with very little in the way of care has produced very few split fruit, although it has to be said they have a habit of 'disappearing' when nearly ripe! 

[beesrus]

Definitely a water thing given the dry conditions this year. My outside tomatoes just didn't get enough water at all, and nearly all my gardeners delight have split like above. Those tomatoes in the greenhouse that were watered very regularly haven't suffered at all.
Apparently, according to my world wide grape picking friend, grapes suffer from the same splitting problem if a hot dry growing period is followed by late rains...

[Geordie]

Thanks for all the replies - I suspected it was the watering.

The varieties are moneymaker and ailsa craig and both are inside the greenhouse in 10" bottomless pots directly on the soil. I would say 10% are affected on each plant.

I water religiously every 2 days and vary the amount depending on the weather. The only variation they could have had was at the end of July when a family member was watering for me whilst on holiday!

I think I'll reduce watering to every 3 days from now on.

Cheers 

[brianbishop]

I am growing craigella, red pear, san marzano, and money maker in P/T direct in soil, have watered little and often, only craigella splitting!!!
Bish

[Headgardener22]

Once the tomatoes have "set" that is they have stopped growing and are ripening, overwatering will cause them to split because the skins lose their ability to grow any more.

Thinner skinned varieties are more likely to split (I find Black Cherry are particularly bad). I think its been particularly bad this year because of the hot period at the end of July.