Potatoes - which compost!

[JamesC]

I want to grow potatoes in containers and was wondering which is the best compost to use? John Innes No. 3 is what I have.

Thanks

[Alice]

Hello JamesC, I'm not an expert although some of the guys seem to be and maybe you'll get a different answer from them. I'm growing my potatoes in pots and using the compost from grow bags as that s what I had. I put a good layer of manure (the type bought from the garden centre) in the bottom. I don't really think it matters what type of compost you use but it is important to feed them and make sure they are adequately watered. If using big containers I put a tube down the middle to make sure water gets right down to the roots. Hope this is helpul. Good luck.

[SueA]

Hi JamesC,
I'm with Alice on the 'anything you've got' compost method. I normally just use multipurpose & anything leftover from old compost/grow bags. You can use compost from pots you've used before for other plants as long as it has no diseases in it as the seed tuber provides most of the nutrients the plant needs, it's just the watering that's important.

[JamesC]

Thanks for your replies.

I will give it a go then - seems that potatoes aren't that fussy!

One thing about watering - I tend to overwater things. Can you do this with potatoes? If they are in potato barrel say, do they need watering every day at this time of year? Just don't want to rot the tubers as I understand that's what can happen?

Thanks

[Nicos]

I would have thought once a week at this stage would be plenty (if that!)- it depends on where you are located? The soil should not be too wet as you will indeed rot them. As a rough guide - if you get a handful of the compost and squeeze a fistful of it and it sticks together then it's damp enough. It really depends on what sort of compost/soil they are in. The surface can look dry and 3" below will be nice and damp -just poke around in it every few days to check it out. Do make sure the barrel's drainage holes are working. Once the plants are in leaf, you will be able to tell if they are underwatered!! Once the weather hots up you'll be able to water more often!

[nick the grief]

If you over water them they'll rot off at this time of the year. I've got some pots under the staging in the greenhouse & I watered these when I'd planted them to settle the soil & they havn'e had any more yet. thats been about 2 weeks. The shoots are just coming thru. You can grow them in JI No3 if you want but I've just used multipurpose mixed with the compost from my old Chrysanth pots which was JI No3 but has probably had all the Nitrogen taken out of it. You don't want a lot of Hi Nitrogen feed as your looking for tubers not tops. What you could do is mix the JI with some growbag to make it go further. then just keep your eye on the potatoes & don't let them wilt once they are growing but don't flood them with water, you'll just wash out the nutrients. Then you can give them a couple of real good drinks to help them bulk up prior to harvesting.

[SueA]

Hi JamesC,
Like Nick I haven't watered my tubers since I planted them as we've had a few heavy bouts of rain, you shouldn't water them every day at this time of year as they will drown. It depends on the weather & where you have positioned them how often you have to water them when they start to grow. If you have them in full sun in a south facing garden you will probably need to water them every day during late spring/summer but if not just do it when they look a little dry.