Advice

[Cranford Steve]

I have noticed that my turnips get smaller towards the rear of the patch, there is a row of conifers the lenght of the garden, could this be the cause? They get sun for most of the day so the conifers dont block out the sun, could they be sucking moisture away from my veg. Nothing else is like this is happening to the other veg, just the turnips.

[Two_Sheds]

my turnips get smaller towards the ... row of conifers

Nail on head there

[Cranford Steve]

But all the other veg near them are ok?

[Two_Sheds]

The soil may be extra dry near the turnips, or they may just need more moisture than the other veg you have there

The conifers will certainly be hindering them though

[Nicos]

I have one massive conifer- it sucks the life out of the soil.
Nothing does well for me within 15 feet of the trunk.( apart from blackberries)
Lack of water and nutrients. (Also- the soil will be a tad more acidic due to needle fall)

Not a good combination.
Worth digging in lots of rotted leaves and other moisture retentive/nutrient rich material.

[solway cropper]

As Nicos has said, the soil will be more acidic near the conifer and turnips, along with other brassicas, prefer a slightly alkaline soil.