What to fill a deep veg bed with? 7 July 2020 at 5:43AM in Greenfingered MoneySaving 10 replies 4.6K views

dllive

Hi
Ive just bought a big 14 inch raised veg bed. Ideally I would have gone for a shallower bed, but thats all they had. I suppose it means I can grow carrots and parsnips which is good.
Do I have to fill it all with soil? (This is a lot of soil!). Or - because my veg roots probably wont reach that far down - can I put in a couple of inches of gravel and other garden detritus to take up a bit of space at the bottom?
Also, as its 14 inches deep, do I need to worry about weeds coming up, or should I put weed preventive material in bottom of bed?
Thanks

greenbee

I’ve built a couple of deep raised beds recently. I’ve put down weed suppressing membrane both times, put a layer of rubble (of which I have lots) in the bottom to help with drainage, then a layer of part-rotted compost (I needed to empty the compost bins) and then a mix of topsoil (the stuff from the garden centre has fewer weeds than the stuff from my garden, which is sieved soil removed from making beds elsewhere and left for a year or so) and commercial compost. I also buried seeper hose A couple of inches under the surface which connects to water butts. I’m now trying to get timers working ...

dllive

greenbee said:

 I also buried seeper hose A couple of inches under the surface which connects to water butts. I’m now trying to get timers working ...

Wow, thats some pretty advanced stuff! 

greenbee

dllive said:

greenbee said:

 I also buried seeper hose A couple of inches under the surface which connects to water butts. I’m now trying to get timers working ...

Wow, thats some pretty advanced stuff! 

I need to make sure they are usable long term - like the greenhouse (where I also need to get a watering system set up) they need to survive holidays and work travel unsupervised! Seeper hose is relatively inexpensive. You need a plug one end and hose connector at the other (plus double ended male connector). And now is the time to put it in - doing it later (as I’ve done elsewhere using the remnants) is much harder work!

dllive

How deep do potato/carrot/parsnips need? 
I need to allow a couple of inches for mulch; and if I have a couple of inches of drainage rubble (of which I also have a plentiful amount! ), Ill probably actually only have about 10 inches of soil. Is that enough do you think?

-taff

Personally, I wouldnt put draininage in unless it's sitting on concrete because raised beds dry out quite quickly unless they're plenty deep and have a large area. For filling, if it's weedy, lay down a membrane, if not, a layer or two of cardboard, along with whatever [clean i.e. not weedy] grass clippings, and compost, any soil, manure, small twigs etc anything that is organic in nature [ not necessarily organic as in no weedkiller IYSWIM] . 10 inches is good enough for carrots, parsnips possibly not, they have a very long taproot, potatoes yes and earth them up obviousy. You can put what you like in but it also depends on when you're planning on planting it up. If you want to plant it now, then you'll need topsoil and compost. If you want to leave it till next year, as I suggested above and you could grow lettuce, radish, kohlrabi, fennel, spinach, etc in that now.

nosuperwoman

I plan to use the Hugelkultur method that Huw Edwards talks about in his book Grow Food For Free. Lay newspaper or cardboard on the ground and the sticks cut to size, then barkchips then organic matter/compostables then garden compost and topsoil . These are the things I dream of now 💭😀

berjou

Not compulsory to fill to the top with soil, but on our (not quite as deep as yours) raised beds we put down a (one that would let water through) membrane to stop weeds, an inch or so of "gravel" to aid drainage, a good quality soil/compost mix and had good results. Use the finest quality soil you can for carrots - if they hit an obstruction (stone ..) they divert all over the place, and we got the bestest tasting ones at 3-5" long. Parsnips similar, but with 12" + to play with i would be looking at spuds too. P.S. membrane might stop weeds growing up, but won't stop weed seeds from dropping on top.Happy Harvest ....

josieberry

Recently watched an Aussie Youtuber suggesting you fill the bottom up with dead wood. It introduces nutrients and microorganisms from the bottom of the bed for great soil health.

-taff

I've given hugelkultur a go in one bed at an old address. Didn't work particularly well, but that might have been me expecting too much. Once it was throughly and irrevocably soaked over the winter, the next year wasnt too bad, it did hold onto moisture a lot better.

philsu

Hi, have a look at some Charles Dowding videos on YouTube to get ideas on what to do, we have built quite a lot of raised beds on really weedy area, we put thick layer of cardboard down first on top of grass & weeds and haven't had a problem with weeds growing through. We had some compost we had made and then bought a bulk bag but remember that you don't really have to fill it completely all in one go to could start planting and top up as and when you can get more compost. If you have an area of grass or soil that you can use elsewhere in the garden dig up the grass in squares and put face down on the cardboard then put some of your garden soil on top then good compost on top of that, I wouldn't put weed membrane down, we did mix a bit of gravel in the bottom layer of one where it was on wet, boggy area but it will dry out quickly if use too much.