Yellow patches on Tomato leaves?

[Smileyk]

My tomatoes have yellow patches on the leaves - any idea what it is?

I feed them once a week so assumed they weren't lacking in anything but something is wrong. I've had this before and ignored it and the tomatoes were fine (and plentiful) but I thought I should make an attempt to working out what is actually causing it!

Thanks!

[Fork]

Probably short of some trace element like magnesium.

[ChrisG]

Yeh you probably need to give them some magnesium.

I had too and just sprinkled some on the soil (in pots) and watered in.  Seems to have done the trick.

Tip - Boots the chemist has Epsom Salts (Magnesium) for £1.50 and you get quite a lot.

[laurieuk]

My tomatoes have yellow patches on the leaves - any idea what it is?

I feed them once a week so assumed they weren't lacking in anything but something is wrong. I've had this before and ignored it and the tomatoes were fine (and plentiful) but I thought I should make an attempt to working out what is actually causing it!

Thanks!

If it is just the lower/older leaves that are going yellow I would not worry.Leaves go yellow once they have served their purpose and younger ones are taking over,some people remove these older leaves but if you let too much sun in it can harden the skins. A lack of magnesium usually shows as yellow areas between the veins rather than all over the leaf.

[tim]

Smiley - does your feed have Magnesium in it - like most Tomato feeds?

(Another post for DISORDERS??)

[Smileyk]

Just checked and the tomato feed does have magnesium in it.  The yellow starts off like spots and then spreads out.  It's not on the very top leaves but it is on leaves from about 3/4 down.

Should I take a pic?

[valmarg]

Smileyk, you probably need to feed more often than once a week.

valmarg

[cleo]

I could be missing something but if they are going yellow towards the bottom of the plant I wouldn`t worry

[tim]

Spots don't sound like Mg deficiency?

[laurieuk]

It really does sound like age, mine are the same and I would not worry.

Just checked and the tomato feed does have magnesium in it.  The yellow starts off like spots and then spreads out.  It's not on the very top leaves but it is on leaves from about 3/4 down.

Should I take a pic?

[davyw1]

The main three dissorders for yellow spots on Tom,s are
Gray Leaf Spot  Spots with a yellow halo

Powdery Mildew

Spotted wilt

[petengade]

Mine are the same, could it possibly be the beginning of tomato mosaic virus?

[davyw1]

Add this to your favourites/Bookmarks.

http://aggie-horticulture.tamu.edu/tomatoproblemsolver/leaves/index.html

[Smileyk]

Great site that thanks!

Could be leaf mold.......

[laurieuk]

It is like reading a medical book,it gives you a lot of things to worry over.