Newbie raised veg bed

[esamuel08]

Hi there,

I live in N. London and I am about to start a 8x4 ft / 12” deep vegetable raised bed in my back garden and just want to make sure my rough step by step plan is ok and confirm a few areas I’m not to clear on. Any help would be rally useful!

So firstly sowing indoors soil I have ordered a mix of seed compost with vermiculite and Shamrock Moss Peat (as well as some extra louse vermiculite to add as well). Will this be OK for just indoor sowing? Anything else I should add that is not to expensive?

After the seeds have sprouted and i get some light on them are normal fluorescent 50w fixtures for example ok? Can they be any type of fluorescents/blubs? What will be enough watts for the standard vegetables? What is a good average temperature for vegetables & strawberries?

Once their true leaves have grown some I should transfer them to larger separate pots and keep them under light?

After awhile start to introduce them to outside for hardening.

Now, the thing that I am finding hard to be clear on is the actual soil in the raised bed. For a soil mix is this ok:

All in liters for a rough total of 900liters excluding some parts like newspaper.

- 200lt Vermiculite
- 300lt “Sandy loam top soil”
- 300lt Mushroom Compost (The topsoil and compost comes alrady mixed in a 50:50 ratio.
- 100lt Moss Peat
- Fertilizer – How much (in KGs) do I need and what are good types? Again not to costly.

Anything else I should add to this?

The plan is to find a grass section and cut a small trim so the wooden bed fits nicely into it. Then dug up some thin layers of grass lawn close by and put that in the bed grass side down. Put a thin layer of newspaper over than then fill with some mulch or just put the soil mix strait on it. Then cover that with a bit of mulch. – I will be planting in this probably within the month. Will that be too soon?

Thanks in advance, E

[Bigmallly]

Welcome to the vine Esamuel. Wow! a lot of questions so I'll throw a few back to you.
What exactly are you planning on sowing as different veg like different conditions, I am just starting to wind down the use of lights with the longer days fast approaching. The mix you have show looks similar to the mix used in square foot gardening, is this what you are planning for your bed?

[Bill HH]

It seems to me you have done a lot of homework and are already pretty clued up. On a raised bed of that depth you could save on costs by putting lots of cardboard and newspapers in the bottom layer, it hold moisture, supresses weeds and encourages worms. Most of us dont use fancy mixes for seeds just normal MPC. As for fertiliser if you can get some manure on top of the cardboard and paper then in the upper layers some blood fish and bone meal it will be appreciated. However it depends on what your growing, carrots for instance dont do well in very fertile ground it encourages them to split. In a 12 inch deep bed you could put up to six inches of cardboard/ paper because once wet it sinks right down. The turf you're adding will also save money on expensive filler. Start a compost bin to top up the bed next year, Keep us posted on your progress.

[Kristen]

After the seeds have sprouted and i get some light on them are normal fluorescent 50w fixtures for example ok?

I have a lighting rig with fluorescent T5 tubes. There is about 1" between the tubes, and the "rig" has to be only an inch or two above the seedlings. Its a lot of bright light, more than perhaps you are anticipating?, and its proximity to the plants is important ("inverse square rule" means that light "power" reduces very significantly the further away the tubes are).

If you need to use artificial lighting then I recommend that you have a look for a hydroponic shop that sells lighting rigs. Tubes (or perhaps LED rigs) best suited to seedlings, whereas Metal Halide is better for tall plants where the light needs to penetrate the canopy (don't put Metal Halide close to the plants they will cook the leaves! I also have Metal Halide and they are a good 2 feet away from the plants)

Once their true leaves have grown some I should transfer them to larger separate pots and keep them under light?

If you put a small seedling into a large-ish pot of compost then there is, relatively speaking, a lot of "soil" compared to the size of plant. You water it, the plant then takes several days to drink that much, meantime the water in the "soil" is preventing air getting in and there is risk of rot. When the plant is bigger it will drink more, the water is thus absorbed more quickly, and air gets into the "soil", and plant is happy

One solution is to, first, transplant the seedlings into small modules - the type that are about 1" square. When the roots start poking out of the bottom then push them out and only then transfer them to pots. (I would suggest 9cm pots at that stage). If you are going to grow the plants on then progressively increase the size of pots once you see roots coming out of the bottom of the pot - i.e. the plant's roots are starting to fill the pot. This way you are much less likely to over water the plants. BY potting-on and because the pot size is "tight" relative to the plant, the plant will form a dense root-ball in each new sized pot you transplant it into. Whereas if you put a small plant straight into a large pot then the roots will tend to grow straight to the outsides, and the circle round, rather than forming a dense root-ball in the middle.

If they are staying in for the Summer (i.e. you will be growing them on in pots) then pot-on, increasing diameter about 1" to 2" each time, until you get to final pot size. If you are going to plant them outside then acclimatise them to the outside (out during the day on nice days, in at night, for a week) and then plant out. I raise my plants and pot-on until they get to 9cm pots and then plant out. Many people use modules which are about 2" square.

The plan is to find a grass section and cut a small trim so the wooden bed fits nicely into it. Then dug up some thin layers of grass lawn close by and put that in the bed grass side down.

If you dig the soil under the raised bed, first, then the vegetable roots can go down through the soil in the raised bed and into the soil below and then perhaps you won't need anything like as much as 12" of raised bed? (and then you will need a lot less material to "fill" the raised beds). Another alternative is to dig out the paths, and put that soil on the beds, so simultaneously you raise the beds more by also lowering the paths. This is a good way of increasing drainage - e.g. on clay soils (which is often why raised beds are used) - without having to buy in lots of soil to build up the raised beds

I will be planting in this probably within the month. Will that be too soon?

It may be a bit early for any "tender" plants that don't like frost, but there are plenty of vegetables that are rock hardy that you can plant at that time (or sooner even)

[veggiechicken]

Hello ESamuel and welcome. I can't add to any of the advice you've been given except to say that I doubt that you will need lights at this time of the year. If you tell us what you want to grow we will be able to be more specific.

[MJA54]

Hi esamuel,

I agree with much of the other replies you have had. You certainly have done your homework!

I did exactly the same thing as you a year ago, same size raised bed on what was grass.

You wont need as much compost/moss peat etc as you think thus bringing your costs down I was surprised at how much volume the lifted turf takes up when you put it back in the raised bed. I tore mine up a bit to encourage it to break down a little quicker underground and to make it easier for the roots of your veggies to get through. Also I agree with the previous reply - definitely you should fork over the soil under where the grass previously was. Again I was surprised at how much extra volume this gives you - and therefore less added material required. This is especially important if your soil is poor draining - which is maybe what led to a raised bed? Our soil here is typical new-build rubbish soil - builders clay, bricks, all heavily compacted If your soil is like ours then maybe worth investing in a bag of horticultural grit, which is pretty cheap and certainly helped open up the soil.

The other thrifty tip is to use any old spent compost from last year - eg old tomato grow bags, MPC from bulbs in containers etc. Although not rich in nutrients it adds loads of organic material which will aid moisture retention.

Finally, and this will not cost you any more than your original suggested mix of products, consider some mulch. I used Strulch, which is composted, mineralised straw which is lovely to handle, reasonably priced, will raise the level of your bed further and is amazing at suppressing weeds. I literally didnt have to do any weeding all season Although I am not too smug for this year, as in the first year everything is pretty sterile as mostly bought in fresh.

I would also say it is worth not filling your raised bed to the brim - which is what I think your suggested quantities of material might do. I have a gap of say 4 inches to the top of the raised bed. You will want to add further mulch/manure etc in future years so leave some space for this.

All in all, I think I used c.250l of bought topsoil which is pretty sandy but also contains fertiliser, the same amount of horse manure, a couple of old growbags and a 100l bag of strulch. And, incidentally, I grew carrots last year with no forking. And had bumper crops of everything else. Although I think Mother Nature played more of a role than me

Good luck and let us know how you get on.

[Bill HH]

You need to be aware that using lights is not commom practice, it is more an advanced technique to get earlier crops or for show purposes. If you're starting out in growing veg you are probably best to leave lights until you feel a real need for them. Most of us are prepared to let mother nature provide the heat and light in her own time. A much more cost effective way of getting an early crop is to buy plants that someone else has raised in a nursery. An example would be tomatoes, they need an early start because they take a while to fruit and may not ripen before the frosts mow them down. But just starting them on a window cill can get over this. The days are already getting longer and is enough now to plant most things. I would probably try lights if i had the room and the money but it is by no means essential and you are implying you don't want costs to escalate.

[MJA54]

I agree with Bill, dont worry about the lights. There is enough daylight

[Kristen]

I agree that lights is not really a thing for newbies ... I got carried away answering the question, rather than questioning it! That said, I think lights are a good substitute for a heated greenhouse. Lights in the house is far cheaper than trying to heat a greenhouse, and is loads better than using a windowsill - which makes plants leggy, and leaning to one side - and can cook them on sunny days e.g. on a south facing windowsill - and a couple of lighting rigs is a lot cheaper than a greenhouse and that's assuming folk have space for a greenhouse.

But watering under lights is tricky - they have a significant drying effect, and seedlings need very little water, so balance between Rot and Right is delicate.

Also lights make for Summertime conditions, and Aphids etc. love them, so bugs are more of a problem growing under lights than just "growing indoors".

[CurlyGreen]

You asked if planting within the month was a bit soon. I believe some things are more suitable for a new bed than others. Potatoes are traditionally good, a lot of my beds had them in their first year. They are supposed to break down the soil.

The new bed we made last year had runner beans at one end, French at the other with a few courgette, patty-pans and winter squash. They all did well. My feeling is for best success you want to plant out strong plants that are already well established plants in pots.

I'm only growing strawberries from seed for the first time this year. I sowed them about a month ago and they are still tiny. I don't think they would cope well with a new bed for a while. Any more experienced people have a view? Would it be better to grow them in pots and plant out in autumn or even next year?

[Two_Sheds]

What will be enough watts for the standard vegetables? What is a good average temperature for vegetables & strawberries?

That's what you need, not grow lights

[Bill HH]

Regarding the original question this bed is not huge and you will need to chooose the right plants, courgettes for instance would take up a significant area. If you cram too much in they all suffer. You will soon be building a couple more beds if you have the space.

[esamuel08]

Cheers for the replies.

What exactly are you planning on sowing

Il be sowing, Strawberries, Bell peppers, Tomatoes, Carrots, Parsnips, Spring onion, Red onion (that are apparently sling as well), leek, Cauliflower (romanesco), potato, lettuce & a few herbs, oregano, thyme, basil and rosemary. - First time so I thought I would try a bit of everything. Yes it will be square ft gardening.

As for fertiliser if you can get some manure on top of the cardboard and paper then in the upper layers some blood fish and bone meal it will be appreciated.

Ok that should be easy to get, thanks.

If you need to use artificial lighting then I recommend that you have a look for a hydroponic shop that sells lighting rigs.

say that I doubt that you will need lights at this time of the year

You need to be aware that using lights is not commom practice

Thats the thing I didn't want to buy an expensive grow light. I heard that its not good to put seedlings by a window as it causes the stems to grow at an angle which isn't good. I understand that its worse in winder with a lower sun. well you guys seem pretty adamant that they won't be necessary now so maybe il give them miss. Although, I can get a my hands on 5x 3ft fluorescent fittings for like £30 (T5 fitting I think) so would it be worth getting them anyway while there going? I have a whole extra room so space is ok.

If you put a small seedling into a large-ish pot of compost then there is, relatively speaking, a lot of "soil" compared to the size of plant.

Excellent, thanks for this. I have ordered some small proporgator trays, like 2x2" to start them off in for the roots to fill out, then transfer once more to fairly larger like you said. I think 1 or 2 transfers is enough deepening on the plant.

which is maybe what led to a raised bed?

As for the raised bed il probably make a decision when i bed the bed not he weekend. it seems like the soil around my yard is more clay than soft loam so il be sure to break it up like MJA said, and yes that is the reason for the bed I will check out Strulch as yeah, id rather not be weeding as well if i can help it. Thanks for all that guys its made it a lot clearer.

plenty of vegetables that are rock hardy

Once i get the bed up and soil down this weekend and give it a week and then start the outside sow for the hardy plants.



Appreciate all the replies guys thank so much,
E

[Bigmallly]

Peppers & Toms will benefit from being grown in a greenhouse, you can get outdoor variety Toms, not sure about Peppers. Avoid growing Parsnips & Carrots where there has been manure, they may grow distorted. I personally would grow Potatoes in either a separate bed of containers as you will disturb the other squares come harvest time. Everything else should be ok in Sq Ft Beds.

[Kristen]

I can get a my hands on 5x 3ft fluorescent fittings for like £30 (T5 fitting I think) so would it be worth getting them anyway while there going?

In January and February it can make a huge difference (but plants you sow then will be huge by the time they can be safely planted out).

Now? No, windowsill has plenty of light.

Put a piece of white card / polystyrene (better reflectors than Kitchen Foil) behind the plants, on the room side, to reflect light and if necessary turn them every day to counteract the "lean" that they may develop.