Tuesday, May 3, 2011

Permacrop 3 - the Sea Captains box

Well today was a bit of work in planning more than anything else. Rather than shore foraging, it is easier to grow and have coastal edible veg close at hand. For that reason I decided to develop a salty box in the perennial bed.
Drainage foundation, free from the garden
I also see, watching programs like masterchief and in top restaurants like NOMA a trend to these delicious but forgotten culinary gems. I guess because they have a short shelf life, supermarkets don't like them, so they have gone out of fashion. They are now presented as exotic, but were once common from fishmongers, packed in casks of seawater for transportation.

There are three veg I want to grow in the box. They are all edible coastal plants, and are halophyte - that is they like, need and /or tolerate salt. In addition to that they all like sandy, well drained soil so that was the requirement.
Scurvygrass (Cochlearia officinalis) is a native Irish perennial and grows to about 20cm in height.
Kind of tastes like a cross between horseradish and cress. For use in salads or stir fries.
It is also of historical interest to me and that's mainly why I'm cultivating it.
In the old days, scurvy occurred on ships spending months at sea without fresh fruits or greens, leading to a deficiency of  vitamin C.
But if a captain stowed a supply of scurvy grass and other sources of vitamin C like lime juice or saurkraut / zuurkool (hence the nicknames limey and kraut) as the 18th-century English explorer Capt. James Cook did, the sailors were safe. He also collected another type in New Zealand called Nau which I hope to get someday.

If you like bacon, that juicy, salty, crispy texture and taste, you will love these next two.
Samphire (Cachrys maritima)  - perennial - grows to about 30cm-ish and can be found in Irish coastal regions, I've also had it in the southern Netherlands, very short shelf life so it's best to grow your own rather than face the expense of it because they have to rush it from the Zeeuws estuaries to the point of sale, but great as a garnish for oysters. 
Its succulent, crispy, salty. Great raw or snipped into salads or soups - almost like vegetable bacon.

Salsola (Salsola Soda) is native to the Med, it grows to about 70cm and is very popular in Italy. Barba Di Frate (or Friar's Beard) is what the Neapolitan's called it while I was there, again, collected fresh from salt marsh's. It is actually irrigated using sea water.
It was fantastic served with cavolo nero and pine nuts, but a word of warning, it is notoriously hard to germinate.
Seaweed, free fertilizer
All of these plants, as I said, live in a saline coastal environment. That means they like brackish water, something between the sea and fresh.
Sea water has a specific gravity of 1.025 - i.e. it contains 25 grams of salt per litre, fresh water has none.
For that reason, and erring on the side of caution I will irrigate twice a week and go with a specific gravity of 1.010 - and you don't need a hydrometer to work this out.
Simply add 10 grams of sea salt or kosher salt per litre. The reason for sea salt is it contains no iodine or anti caking agents. The average watering can holds about 8 litres - that's 80 grams of salt per can.

Obviously I don't want the salt leaching into other beds, so the bed had to be prepared differently to the normal set up, especially as I included it in the perennial bed.
This took a bit of thought as it had to be lined and drain in a way that would keep the salt away from other plants, and it had to be quite sandy.
Initial outline
I came up with this scheme, a plastic sleeve made up of old feed bags that would drain freely into the bedrock / glacial sand base that is in the garden and was a 2 ft transverse box in the perennial bed

The other consideration was orientation, this was done on the basis of height. The bed lies facing NE, so the transverse runs SE. Salsola grows to about 70cm, Salsify to 30cm and scurvygrass to 20cm max, so that settled the issue.

Apart from that its step by step.

1 ) Cut a transverse trench across the bed, getting down far enough that salty water wont affect other plants, beds or bed sections. By the time I was happy, I had gone down about 24 inches / 60cm below the base of the side retaining boards in the raised beds.
2 ) Put in and secure transverse retainer boards either side of the trench
3 ) Clear the trench to the drainage zone and put in rocks to improve water flow
4 ) Tack in the plastic sheeting (I used old feed bags) around the edge of the box, to separate the salt box from neighbouring sections. Turn the bottom of the sheets inward and line the rocks carefully to hold it down.
The trench width was 2 feet / 60 cm, the width of the drainage sink at the bottom was about 18 inches / 45cm.
5 ) Next step was a layer of sand roughly raked in to fill in between the rocks and provide a free draining base
6 ) After that, a layer of dried seaweed that I ran through the new garden shredder - made a nice tidy job of it.
7 ) Then the backfill of soil well mixed with beach sand, always aiming to have very well drained soil to replicate the littoral maritime environment. The side that the Salsola and Samphire were going into got a bit more earth as they are succulents and are more fond of water/mud than scurvygrass
8 ) After that it was planting the seeds, marking them up and giving a top dressing of seaweed for extra nutrients. I also started to put in a cap around the box to secure the plastic on tom and give a better look to the bed.
I hope, and think, the scheme will work - and it does fit in well with the overall bed.
I hope you enjoyed the post, and if you found it of help or have any comments please do take the time to leave a message here at the blog, I love the feedback


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  1. What a novel, original and fantastic idea. Living in Offaly, a sea-side salad box would be the only way we'd get fresh sea-greens! We've nothing in the plans for one at the moment, but we're very sorely tempted by this idea, and your wonderful instructions on how to prepare it - where did you get your stock from?. Interestingly, I think this is the thiird time I've heard Samphire mentioned in the last few days so clearly its becoming trendy!

  2. Looks a fine job. To busy in the garden at the moment to attempt a copy but hope have a go sometime

  3. Hi Offaly and Jim, thanks for the feedback.
    Salsola seed was bought on line, seed for scurvygrass and salsify foraged but can also be got online, realseeds.co.uk do a lot of stuff like this, and New Zealand Spinach is another useful addition
    With Samphire tricky to source, and 9.50 per kilo apparantly its probably worth a shot if you have space

  4. Excellent informative blog- a book in the making!

  5. Can you let us know in your honest opinion what are the best and most competitively priced polytunnels available in the republic?


Thanks for commenting - its cool that you took the time