When to fertilize here in the uk

[palm789]

As the title explains it, when? 

my palms are light green and need them back to bottle green, I got told to fert them but the weather is bad just raining all the time but spring is trying to push through, I got slow release and liquid feed,also anything else I need for them to help them get their nice green colour back, I got windmills planted in nice draining soil a year ago. Any advice guys????? 

[Arecaceus]

I'm not in the UK but in Atlantic Western Europe and I usually fertilise in early March, sometimes mid march depending on the weather with a slow release fertiliser. It's working for me perfectly for years now. This way they get a good start into summer and access to nutrition as early as possible but not too early when plants can't take up all the fertiliser and it gets washed out by the last winter rains. As you mentioned your Trachies being planted in draining soil. How draining? And do you have massive amounts of rainfall? Because from what I know Trachies don't really need too much drainage. I'm saying this because I'm just hoping that nutrients are not getting washed out too much.

[palm789]

It drains faily good from above, it absorbs in right away within 5 seconds.

I gave up with my trachys in my back garden due to poor drainage, so transplanted to the front gardens, I thought hell with it so no soil amended and jyst planted in pure clay. 

[Foxpalms]

4 hours ago, palm789 said:

As the title explains it, when? 

my palms are light green and need them back to bottle green, I got told to fert them but the weather is bad just raining all the time but spring is trying to push through, I got slow release and liquid feed,also anything else I need for them to help them get their nice green colour back, I got windmills planted in nice draining soil a year ago. Any advice guys????? 

It depends on the temperature. Here in London it's been around 16-14c for the past week and whilst it has rained a few times, it's been more drizzle for only a few hours. I fertalized my queen palms and gave them a water because the soil was pretty dry. Trachycarpus are not as tropical as queen palms so they probably can uptake nutrients from the soil at cooler temperatures. It might be worth fertilizing them on a drier day if you are having excessive amounts of rainfall in Wales. 

[Arecaceus]

4 hours ago, palm789 said:

It drains faily good from above, it absorbs in right away within 5 seconds.

I gave up with my trachys in my back garden due to poor drainage, so transplanted to the front gardens, I thought hell with it so no soil amended and jyst planted in pure clay. 

Well sounds very draining but anyhow if you have deficiency you need to fertilise. Depending on the temperatures you have I would start using an immediate fluid fertiliser on a regular basis and also give it some slow release fertiliser for the summer. I'm not completely sure but I think they will only start take up nutrients at around 15°C. Maybe even a bit lower if the sun's out and you're using quick release fertiliser on the leaves.