Blocking Up – experimenting with peat-free soil blocks

I can’t quite remember where I first came across the idea of soil blocks for seed sowing, but they’re a rather neat idea. Compacted cubes of growing medium are used instead of pots or modules, freestanding seed trays with narrow air gaps between the blocks.

Big claims are made about the benefits of soil blocks for raising young plants in terms of reduced root disturbance and how ‘air-pruning’ of the roots prevents root binding of seedlings, all of which may well be true – I haven’t really got the horticultural background to say! But actually the thing that really attracted me to soil blocks was practicality.

Sowing seeds into soil blocks

I really don’t like module trays – they’re a pain to wash and re-use, if nothing else, they tend to degrade badly and crack up so that they only last two or three seasons, and are expensive and enormously wasteful if you’re using them only once. While it makes sense  to start certain seeds directly into 3″ pots, that takes up an awful lot of window sill space – something that’s definitely at a premium in my house at this time of year. And as we’re aiming to be completely peat free in the new garden, those little peat jiffy pots are right out (and the cost adds up quickly). A useful compromise has been home-made newspaper pots, but there’s quite a lot of effort involved in making these and I don’t always have time (also, my paper potter tool seems to have gone astray in the house move)! I’d more or less settled to using plain seed trays and pricking out seedlings at a small size, but that’s quite a lot of work and it can be rather traumatising for the seedlings, and has to be done at just the right time when inevitably I have too much else to do. So, no perfect solution.

Half trays of soil blocks in heated propagatorSoil blocks combine the convenience of the plain seed tray with the ‘modularisation’ provided by plastic module trays or individual paper pots – so could they be the best of both worlds?

Despite a real lack of cash just now, I decided to dig deep and find the twenty pounds for a four-block two inch cube soil block maker, which I bought from GreenGardener.co.uk. Only after diving in feet first with the purchase did I stop to consider the peat free problem; almost everything I read suggested that a peat-based seed compost was essential for making functional soil blocks. So had I just wasted my money?

Unwilling to compromise on our principles, I set about mining websites and gardening forums in search of a peat free recipe for soil blocks. None was quite right but some themes kept recurring. A base of peat free compost (fine textured seed compost ideally), something to help drainage (sand, perlite and vermiculite were variously mentioned) and loam or topsoil to help bind the mixture.

I’ve mentioned that money is a bit tight; going shopping for extra growing media is not on the cards, but I have a reasonable supply of New Horizon peat free organic multi-purpose compost and a rather soggy old bag of vermiculite (I generally use the New Horizon compost mixed 3:1 with vermiculite as my seed mix). We also have an almost inexhaustible supply of molehills, as the efforts of Mr Mole to create a ‘des-res’ for Mrs Mole are in full swing on our paddock!

So with a ‘make-do and mend’ attitude I did a few experiments and have come up with the following mix that seems, so far, to be working well for me. It will be the basis of my soil blocks for this season, while I get a handle on how things go germination-wise, and consists of –

  • Dry soil block mixture4 parts peat free multipurpose compost (you could sieve this to take out the biggest bits – but I’m fundamentally lazy and don’t own a garden sieve)
  • 1 part vermiculite, and
  • 1 part molehill (you should ideally sterilise this to get rid of weed seeds, I suppose, though it seems like faff) or substitute with bought topsoil (being careful it’s not been mixed with peat compost, as it often is!)

Wetted soil block mixMix the components thoroughly and then add water, a little at a time, until you reach a consistency that holds well together when you take a handful and give it a good squeeze. I find this is at the stage that you can just squeeze a tiny bit of water back out of the mix. Any wetter and the blocks slide straight out of the block maker – drier and the blocks tend to crumble. If you find you’ve over-wet the mix just add a bit more compost to dry it out again. A little trial and experimentation and you should get a good idea what you’re aiming for.

Filling the soil block makerTo make the blocks, level the wet compost mix about two and a half inches deep and as even as possible. Push the block maker down firmly into the compost until it hits the bottom, then push down on the handle without moving the press, to squeeze down on the blocks. You may squeeze a out a little water (if you’re seeing a lot, your mix is too wet). Then, release the handle and carefully pick up the block maker, tilting it on it’s side to reduce the risk of blocks falling out.

Making up soil blocks in seed trayPosition it where you want your blocks to go, and then press down on the handle again pulling the block maker up at the same time. If it’s all worked perfectly, you will have four even, neat little cubes each with a dimple in the middle. I find I can fit three rows of four blocks (12 blocks in total) into a half sized seed tray or seven rows of blocks (28 in all) in a full sized tray.

Half seed trays of soil blocksNow you’re ready to sow your seeds. Pop one seed into each dimple (or more than one if they’re small seeds and you plan to thin any extra seedlings) and cover loosely with a pinch of dry compost or vermiculite – or leave the seed uncovered if light is required for good germination. Then place the seed tray in your desired spot. I currently have two half trays of soil blocks in my heated propagator with tomato seeds in, and two full trays of salad leaves and brassicas in the unheated greenhouse.

Completed tray of soil blocksThe soil blocks are supposed to contain enough water to allow the seeds to germinate without further watering being required, but this depends on preventing excessive evaporation.

Covered seed trays in greenhouseI wrap the seed trays in the greenhouse with cling film (wetting the edge of the seed tray like a pie dish gives a good seal) and those in the heated propagator are under a closed lid. But if they do get a bit dry, don’t panic – mine held together fine when I watered them with a normal watering can and medium rose, just be gentle! Obviously you can’t use normal plant markers easily if you’re using cling film, so I label my trays using masking tape stuck to the seed tray. Keep your eyes open for signs of germination and remove the cling film before the seedlings reach it.

I’m waiting to see how things germinate in them now, and how they grow on, with no small degree of excitement!

Are you experimenting with soil blocks this year? How are you getting along?

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April Showers Bring May Flowers

It’s finally feeling like summer is coming. But a time of year that would normally see me full of excitement and plans for the garden and kitchen is instead leaving me feeling bereft!

It’s not something I’ve been talking about here, but for the last six months, Hubby and I have been negotiating the frequently infuriating, frustrating, and quite honestly heartbreaking process of surrendering our beautiful home to the Department for Transport so that their friends at HS2 can build a high speed railway line through it. In some respects our entire time here –  in this beautiful piece of rural England, in the cottage that we hoped might be our home for the rest of our lives – has been overshadowed by HS2, which was announced six months after we arrived, ironically on the very day that a huge box of bare-rooted saplings – the orchard I had always wanted – arrived in my kitchen.

So, this year, there have been no window sills full of seed trays. No greenhouse full of tomatoes and chillies (no greenhouse at all, any more – it has gone to live with a friend in the village). No cut flower patch. I’ve had to sit on my green fingers, and it’s been the worst kind of torture.

My poor potted orchard!The only thing we’ve done that could be considered to be ‘gardening’ has been the heartbreaking task of digging up my beloved orchard trees – which will otherwise end up under three metres of backfill – and transferring them into pots, and which felt like nothing more than an act of vandalism.

Of course, just to make me feel worse, everything has decided to blossom this year, most of them for the first time ever! I’m assuming this year’s fruit harvest is a write off, but hopefully my precious trees will survive the abuse, and go on to thrive in their new home.

In six weeks time (fates willing!) we – with the hens, and the trees, and Dave dog – should be just starting to find our feet in our new home in Cornwall. We decided to take the plunge, and make the move we’ve been talking about for years as ‘some day’, to make an opportunity out of what could so easily be a small personal tragedy.

Elderflower buds, just breakingFor now, though, the elder is starting to burst into flower, and yet another highlight of my culinary year is about to pass me by. I could cry!

While there will almost certainly be no elderflower champagne for me this year, there’s no reason you should miss out!

Zested citrus & elderflowersElderflower ‘champagne’ was a great favourite of my grandmother’s, and a few years ago, just after we moved to the cottage, I decided to explore it for myself. It’s been my gateway to a great adventure with all sorts of home-brewing, and is still one of my favourites. It’s so simple, everyone should give it a go!

However, there are two little ‘gotchas’ that I’ve come across with elderflower champagne. Firstly, this live-bottled brew can over-pressurise and create ‘bottle bombs’. Not something that has happened to me personally, thank goodness, but this is mostly because I absolutely insist on using only plastic soft-drinks bottles for this feisty little number. Secondly, if you make this brew with whole flowerheads (and I usually do – it’s a lot of hard work otherwise!), rather than hand-stripping the flowers first, it has a very short shelf life.

Ready to drink!While it’s still actively fermenting in the bottle, all is well, but after three or four weeks, as the brew is ‘fermented out’ and starts to drop clear in the bottle, the flavour begins to turn bitter. Insidiously at first, but pretty soon it will be undrinkably unpleasant. So don’t try to lay this stuff down – enjoy it at its fresh best, start drinking just as soon as you like, once the bottles have pressurised, and enjoy the batch as the sweetness diminishes (and the potency increases!) over the next couple of weeks.

Elderflower cordial, steepingElderflower cordial is another great favourite, and my larder will be the poorer for not getting a batch laid in this year. Again, home-made is the simplest of things. There are no gotchas here, and since I found out about using a little campden powder (wine-makers sulphite), I’m quite happy to lay it down in wine bottles in a cool dark place, where it keeps perfectly for at least a year. If you’d rather not use sulphites, then make a small batch and keep it in the fridge, or freeze a larger quantity using well washed plastic milk bottles or tetra-packs that have held fruit juice.

Diluted with sparkling water, with a handful of ice, it’s a wonderful refreshing drink on a hot day, and a taste of summer in the depths of winter. And the leftover citrus fruit makes a wonderful elderflower-infused marmalade, too!

Last year I made a small experimental batch of elderflower and lemon gin, and some elderflower vinegar. I can report that both of these were excellent – though the lemon gin would have benefited from having the rind removed after a couple of days, leaving just the elderflower to infuse for longer, as the citrus overwhelms the floral character a little.

The elderflower vinegar has amazed me (and the very small number of people I’ve shared it with!). It captures absolutely all of the beautiful sweet scent of the fresh elderflowers, without sugariness, and makes a quite remarkable simple floral vinaigrette! It’s so good that I may just try to make some this year, even if I can’t manage anything else with the house move imminent!

While I’m on the subject of flower vinegars, I absolutely must mention (and heartily recommend to you!) chive flower vinegar, since chive flower season is here or just around the corner. This is remarkable stuff – for a start, just look at the colour!

Chive flower vinegar

The flavour is great – all the fresh onioniness of chives, but without the ‘hot’ character that often comes from raw alliums. It is the simplest thing to make – even a jam jar quantity with a dozen or so chive flowers will be worth your effort – and keeps at least a year in a cool dark place (do beware light – the colour will degrade very quickly even if it’s not in direct sunlight!).

So there you go – May flowers; the figurative ones are hopefully just around the corner, and as for the real ones, they not just for looking at, but for eating too! So enjoy them! And while you do, spare a little thought for us poor up-rooted souls..?

More of this to come!This wonderful little cottage has been so good to us – we have learned so much from being here, and this blog undoubtedly owes its existence to our having made it our home. It’s going to be a real wrench to leave (and heartbreaking to think about what will happen to this little patch of heaven soon) but hopefully, for us, it’s a step on the way to another, bigger adventure!

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