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I really want to grow asparagus. I know its going to be at least a couple of years before I will get anything, but that's ok. My question is to do with soil preparation. I've done some reading and it appears asparagus likes a well drained soil rich in organic matter. (I am open to correction at any point as I am a complete novice with this plant!) The problem is the allotment is on red Devon clay, fertile when well cultivated, but definitely very heavy and wet. I have thought about growing it in a raised bed, which should help the drainage, and maybe adding horticultural grit and / or sharp sand to help the drainage and garden compost and well rotted manure to increase the organic matter.

Would this help to give the asparagus the conditions it needs? Also. what kind of quantities of the various soil improvers would be needed? I have had a look at grit and sand and it appears to be sold in 25 kg bags. I have access to well rotted manure, and the composters are producing well. The bed would be approximately 1 metre by 2 metres in size. One final question, can anyone recommend a variety that is more tolerant of heavy soil? Sorry this is so long and detailed, but I would really value any advice anyone can give!

Thanking all the experts in anticipation!
KK

Get it from a specialist supplier, not a garden centre. I tried the latter twice, and had total failures. This year I sent to this site http://www.asparagus-in-kent.co.uk/growyourown.htm . I bought ten each of Ginjlim and Backlim; htey came at the end of March, and they're still coming up slowly. 18 out of the 20 have emerged, all looking really strong. I don't know whether they'd still deliver this late.

It's just a matter of planting in trenches, about six iinches down, give or take, and adding loads of organic material.

Buying sand and grit in 25kg bags is expensive - especially for what you're going to need. Buy both from a builders merchant in tonne bags - sharp sand is about £50 per tonne.
You don't say how many crowns you want to plant, which determines how big your bed will be. As you're not using washed horticultural sand you'll need to do the prep now - you've pretty much missed the planting window for this year anyway.
Assuming your bed is 1.2m wide (4ft) and say 3m long (10ft) a tonne bag will give you a covering of about 22.5cm (9"). for a bed this size you'd probably only need to dig about half this much in. Make sure you when you dig the bed you double dig it - were it me doing it I'd spread the sand then dig to ensure the sand was well worked in.
In the autumn you then need to dig in about the same again of well rotted manure. By the time all this has settled next spring you'd get a lift of about 5" in soil level. If you can get really old horse manure, at least 3 years so it like top soil then save enough of this to cover the crowns when planted to a depth of 3 inches.
Thankfully my asparagus is not going on the plot on clay but on a heavy loam which is less prone to water logging, but I'm putting it in a raised bed anyway.

Thank you for the advice and the link. It's a fairly long term project, so I am not in any immediate rush to plant! I am planning to get the bed (s) prepared over the summer / autumn while the weather is reasonable to make life easier for me and order the crowns when the catalogues come out, so I guess I won't be planting anything until next spring. That;s ok, I'd rather get everything prpepared, to give them the best possible start. For once in my life I am trying to be organised and plan a bit rather than acting on impulse and making expensive mistakes. The heavy rain this week has helped me identify a couple of possible sites on the plot that are better drained than the rest, and I am planning to start raised bed construction soon!
KK

Hi,

I have had Asparagus going for three years now and it hasn't done very much. Pretty much covered in Buttercups, despite my hard wedding and when the Spears do eventually come up, they are really struggling with the clay. So i decided to lift them today and they were virtually sitting in water, all very soggy thick clay.

Now that i have lifted them, should i replant in pots for now while i prepare a new bed? or just start again with year old crowns ?

Thanks for your help!

AC xx

As long as they're reasonably healthy they should be OK, but if it's that soggy you probably need a raised bed. Buttercups (assuming they're the creeping variety I have) will succumb to ruthlessness and heavy mulching to smother them.

thanks for your reply!
So with the tubes I have jsut dug up, if i plant them in a sandy compost raised bed, we should be doing ok?

Asparagus don't like sandy soil. They like well drained soil with a lot of humus. If you're going to pot them up mix bagged topsoil with multi-purpose compost 50/50. If you're worried about drainage add a little grit or coarse perlite.

Ours are on bog standard clay... well worked and with a 2" layer of well rotted manure over winter...  ;D

ok excellent, thanks!!