Browsing Tag

nitrogen nodules

Vegetable Garden

Kale, Kale and Cabbage… we love our greens!

May 26, 2011

Life’s been pretty busy here in the Sewelly household with one thing and another and I’ve been aware that the planting in our own garden has been falling behind (apart from the polytunnel which is immaculate ☺)

So on Tuesday as I was working away at the computer, and knowing that my chances of visiting a local garden centre soon were slim, I ordered some winter cabbage and pea/bean seeds online.
I have a few favourite seed suppliers – see here for links  and one of those is  The Secret Garden Centre based in Newmarket, Cork. 
Brian and Sarah (owners of the centre) recently revamped their website and it’s a delight to visit. Packed full of colourful pictures and tempting gift ideas, the site and online shop are easy to navigate and hold just enough seed varieties to choose (organic, heritage and regular) without overwhelming.
I first came across The Secret Garden last year when I was searching for green manures, organic pest and disease controls and Bordeaux mixture, all of which they stock. If they weren’t so far away I’m sure the girls and I would be regular visitors, sampling some of their cake and watching the ducks and nesting birds.
I was delighted to find the seeds in the postbox this morning (just two days later), and as befitting the garden centre’s Irish Green Awards status, they were packed securely in a recycled jiffy bag.
I haven’t prepared the legume bed in our garden yet so tucked those packets away in the seed tin and immediately headed outside with my Cabbage Winnigstadt and Cabbage Holland Late Winter, both organic seeds from Suffolk Herbs.
This year two brassica beds have been put aside in the garden (we like our greens and could even go a third if we had the space). The first already has kohl rabi and swede at small seedling stage that were sown directly a couple of weeks ago and today I transplanted some Kale Kapitan, Black Russian Kale and Scarlet Curly Kale that had been started off undercover.
In previous years due to lack of space, windowsills and polytunnel I’ve sown all the brassica seeds directly into the soil. This year I’ve started as much as I can inside. This should benefit the seedlings in that they’ll be much more able to withstand attack from the dreaded slug and the worst of the weather.

The second brassica bed has had a green manure of field beans growing in it over the winter months. The nitrogen  fixing nodules will benefit the cabbage and cauliflower crops that are due to be housed there once I’ve dug the beans in and weeded it. So once again, I set too planting the tiny seeds into modules, bringing them on under the protection of the tunnel until a) they’re big enough to transplant and b) I’ve prepared the bed.

It still surprises me how much you can do in an hour. It never surprises me how much better I feel after some time pottering with the plants, and I now have the added bonus of that  feel-good factor when you know you can tick off a few more jobs from the seemingly never ending list.
Vegetable Garden

Pea and bean crops – do they contain enough nitrogen to benefit anything else?

April 4, 2011

Pea and bean crops - do they contain enough nitrogen to benefit anything else?I just thought I’d share this fabulous photo taken by one of the Goresbridge Community Gardeners, who captured a picture of nitrogen nodules on a field bean I took along to show the group last week.

Over the winter months I’ve been growing field beans in one of my veggie beds as a green manure. Green Manures are used as a means of adding organic matter back into the soil, and are particularly handy for people who’re growing veg and don’t have a ready supply of organic matter (compost or manure).

As members of the legume (pea and bean) family, they’re able to make their own nitrogen and are known as nitrogen fixers.  Legumes store it in little nodules (as can be seen here) and once the nodules have separated from the plant or the plant decomposes, the nitrogen is released and is available to other plants.  Plants from other vegetable families get their nitrogen from the soil, usually from plant debris (or from fertilisers).

Green manures from the legume family are therefore great to grow before anything from the brassica family (cabbages etc) as the big leafy green crops will relish the additional nitrogen and are unable to make it themselves.

*It might surprise many gardeners who are familiar with crop rotation that botanists now believe that the root nodules accumulate half of the total nitrogen and that it only becomes available to other plants when the nodules are removed from the plant.  This only happens when the plant is severely stressed from shade or drought or when the root dies.

Also, when the plant is young about 40% of the nitrogen is in the roots with the rest in the foliage and stems. Once the plant has flowered the reserves of nitrogen in the roots drop to 3-6% with 8-10% in the leaves and stems. The remaining 70-90% is stored in the seeds and seed pods.

What this means for most of us hobby gardeners is that the roots of the pea and bean crops that we have allowed to flower and fruit for the cooking pot are unlikely to be of any nutritional benefit to the veg following them in our crop rotations as is currently believed…. green manures are the key.

* Source Chris Beardshaw – How Does Your Garden Grow