[Lincolnshire Floyd]

throughout the year, and for everything - not just potatoes

Only newly sown or transplanted crops need watering, for a while.

Celery needs regular watering to prevent it from becoming bitter and tough and hardly good enough for anything.

Wild celery is a marsh plant and its modern cultivars need a plentiful and regular supply of water throughout the season.

[devonbarmygardener]

throughout the year, and for everything - not just potatoes

Only newly sown or transplanted crops need watering, for a while.

Celery needs regular watering to prevent it from becoming bitter and tough and hardly good enough for anything.

Wild celery is a marsh plant and its modern cultivars need a plentiful and regular supply of water throughout the season.

Another thirsty crop - celery and celeriac

[mumofstig]

I tend to just water everything every other day so maybe I'm wasting water. Which is a shame because I've been growing things for 7 years now 
I've often wonder if I water too much. Obviously I need to water the seed beds and things I've just transplanted everyday but what about the rest. Let's say we have a week of dry weather at 25 degrees (unlikely I know) how often would you water the following in that week?

Potatoes
Onions
Carrots
Lettuce
Sweetcorn
Courgette
Runner Beans
Cabbage

I would do the dig a small hole test as advised by the RHS (and me) personally I'd also water the lettuce to stop it tasting bitter.

on my soil I don't try to grow celery   

[devonbarmygardener]

Me neither mum - it's too fussy for me!
But I am trying celeriac again this year - so far so good.

[BicesterKev]

Really?

Is it a common misconception then?

But people are watering frantically, everywhere, everyday at the allotment......

If you water daily, you will always HAVE to water daily as the plants will only produce surface roots.
If you only water well, twice maybe 3 times a week, in really dry periods, the roots will develop deep down to find their own water and you will have stronger plants.

You can also wash a lot of nutrients from the soil by overdoing it

I've read quite a few books and none of them have mentioned what you say about the root system - which when you think about it what you are saying makes total sense. Thanks very much for that bit of info (Simon Watson also mentions it - thanks), you have probably saved me and god knows how many of the less experienced gardeners on here several hours a week of plot visits to do the watering every night.

[grendel]

I have 2 off 4" pipes 18" long half buried in my patch of tomatoes, every few days I fill them up with water, which is released 9" down, straight to the deep roots, same system my dad uses.
Grendel

[Lincolnshire Floyd]

I've read quite a few books and none of them have mentioned what you say about the root system - which when you think about it what you are saying makes total sense. Thanks very much for that bit of info (Simon Watson also mentions it - thanks), you have probably saved me and god knows how many of the less experienced gardeners on here several hours a week of plot visits to do the watering every night.

Some plants have shallow roots AND need watering when conditions are dry. If you don't water onions when they need a good drink then you won't get a decent crop, they just won't grow and firm up. A few years ago when we had that very dry summer the onion crop was abysmal right across Lincolnshire.

[Buddleja]

This was just the question I was planning on asking this evening!! Beat me to it. I was reading on the train about water shortages and it made me think about how much watering I'd need to do now that I've got an allotment. I'm glad to hear I won't need to go to the allotment every night -not that I'd be able to anyway.

And I don't plan to grow celery 

[ilan]

Its a case of knowing your crops But also giving the soil a good hoeing is as good as watering as it breaks the surface up reducing capillary evaporation. Then when you water give it twice as much so it gets deep down into the soil You want the roots to go deep to find any nutrients as well as water .

[snowdrops]

For crops that need plenty of water I sink in 2 litre plastic bottles with the bottom cut of,neck side down either next to the plant-courgettes/pumpkins/tomatoes or every other plant-runner beans or every four plants-sweetcorn l then fill the bottle with water if there has been no rain or when they are fruiting. This also delivers water to the roots & helps stop evaporation & run off in hot weather.

[Growster...]

Mumofstig is absolutely right about the spade depth test. Onion roots can go down way beyond a spit depth, which is where there will still be enough moisture to keep them going, as well as more nutrients as well!

I also try only to water with a measure of liquid feed, hopefully just before it rains, so that it all gets shoved further down the soil levels!

Celery is a notoriously difficult plant to maintain in a happy condition, and celeriac is just voracious and takes a long time to get to a reasonable size, even after all those four-course meals...

As my old chum Terry always said, 'Don't water unless it really is all dying off; just let the roots get down to where the grub is...'!

[Lincolnshire Floyd]

The valuable points made were know your soil and the ambient weather conditions.  Good advice for anybody getting to know their land. To be honest, I've never had to water celery or radishes.  Or potatoes or onions in the ground.  But, I grow on clay and get a fair bit of rainfall so, what I do doesn't necessarily fit those growing on more free draining soils etc and vice versa.

Watering is down to judging your own conditions. Making generalisations can be inappropriate in my view. Celery can take as much water as you can throw at it in any soil. It thrives sitting in water and I believe can be grown hydroponically commercially. That's why it's so tasteless when bought from supermarkets. If there is one vegetable that tastes totally different to shop bought stuff then celery is it and it needs water to avoid a strong bitter taste. Plenty of it.

[grendel]

I seem to recall Growster saying that like me he puts his onions in about 3-4" deep to start with, I must say that when I do this they never get extra watering and are an absolute pig to pull up, the roots go down at least a few more inches, so to at least 6" depth, I dont see any point in just popping stuff on the surface, too easy for the birds to uproot and steal.
Grendel

[devonbarmygardener]

I always plant onions at the bottom of the lower half of my plot or the bottom of the top half of my plot as the water drains down the slope to these 2 areas.
It is a gentle slope compared to the plots on the lower half of the site but onions seem to swell best in these places.

I will water them (rather, soak them) well if we have had no rain for 5 days as they do like a lot of water.

[Beetroot queen]

I water about once a week and occasionally give them a can if they look thirsty, or is that just so I have an excuse to stay longer