Polyculture & seed endophytes
Do you rotate your crops or do you go in for a bit of vegetable freestyling and create interesting and productive polyculture beds? Plus the importance of endophytes for seeds
With the weather improving and slugs on the decline (I hope), I have been busy in the garden trying to plant out all my veg before it is too late. The potted squash are already looking a little yellow so they had a feed before going out in my hugelkultur-style raised bed where they should find plenty of nutrients to keep them nourished through summer.
I’ve also finished planting up my polyculture beds (so much later than last year!!). Those of you who have read my books know that I’m not a fan of crop rotation. It’s not that I haven’t rotated in the past - I grew up with a grandfather who always rotated his crops as recommended by Percy Thrower of Gardener’s World (and that’s a name from the dim and distant past, pre Geoff Hamilton no less). And all the gardening books of the time went into great detail about how you could grow crops on a 3,4,7+ year rotation. And of course in organic standards, you are expected to rotate your crops to build fertility and reduce pests and disease.
But the more I learn about soil and how people in other parts of the world grow vegetables, and listen to some of the more innovative farmers and growers, the less convinced I am for the need to rotate and I have moved away from a rigid crop rotation to something more fluid. Its something you will see in Kim’s garden too and Kim is an expert freestyler when it comes to her veg beds!
Most of my crops are intercropped, that’s growing small blocks or rows of crops between other crops. This makes it more difficult for pests to locate their host plants and disease to spread. Add to this mix a lot of ornamentals, and the vegetable area soon takes on a cottage garden look. For example, a bed may be mostly climbing peas and beans, but I plant courgettes underneath and squeeze in a few beets, celery leaf and tomatoes at the end of the bed. While in another bed I may have squares of spinach, celeriac, parsnips and beets with plenty of chives, nasturtiums, calendula, and French marigold.
When choosing what crops to put together, I think about root structure, leaf size, final height etc. I find beets, carrots, chard, celeriac, leeks, onions low growing legumes work well together, along with secondary crops of lettuce and radish.
I prefer to keep the potatoes and most of my squash in their own beds (except for those in the 3 sisters bed) because of their competitive nature and sprawling growth form. I put the larger brassicas in one bed as I grow them under butterfly nets to protect against the white butterflies and pigeons. So, while I have just one crop type in the bed, I’ll plant a mix of varieties rather than all the same kind, so I have plenty of genetic diversity.
Intercropping doesn’t usually affect your yields. In fact, the benefits of the ground cover and the different demands on the soil, mean that the overall yield is likely to be larger. As the secondary plants get larger, they will start competing and then you have to prioritise the main crop by thinning out or removing leaves, so more air can circulate and harvest early if necessary.
Transferring microbes from plant to seed
Last week, I discussed the John Kempf and Rick Clarke podcast in which they were discussing soil and the work of Christine Jones. There was something else that interested me and that was the transfer of microbes in seeds.
So I did a bit of reading. There has been a flurry of research in recent years and we now know that if you open a seed not only will you find the stored reserves, such as starch, but billions of endophytic microbes. Endophytes are microbes that live in a plant, and are mostly symbiotic.
Every plant species is known to carry endophytes, and in fact, depriving a plant of endophytes makes it more vulnerable to stress and disease. So seed borne endophytes are a really exciting area of research.
Why should seeds carry so many endophytes? Researchers have found that they will enable a seed to stay dormant in a healthy state in the ground and facilitate its germination. The exciting bit is that these endophytes are passed from generation to generation - it’s the parent plant’s way of making sure their offspring have the best chance of survival. Once germination has occurred, these microbes can establish a new endophyte community. Some will migrate to the roots where they stimulate the formation of root hairs and may get expelled from the root hairs into the soil where they take up nutrients and are taken up again by the roots (see last weeks post on rhizophagy).
So this shows how important it is to save your own seed, and may be swap seed so you bring in more endophyte dIversity. Does the surface sterilisation of treatment of commercial seed affect the endophytes? I don’t know but would be interesting to find out.
Coming up soon….
I’m off to RHS Hampton Court tomorrow and Kim is speaking on Saturday. So next week will be a Hampton Court special ….
Happy gardening
Sally
Events and talks
RHS Hampton Court If you are visiting the festival next week, come and listen to our talks, Sally is talking on Thursday 4 July and Kim is at the festival on Saturday 6 July
London Permaculture Festival, Sunday 7 July 11 am - 6pm
If you live in London or nearby, come along to the Festival - it really is a great day out with lots of speakers, stalls, Chelsea Green bookstall, and lots of activities for families. Sally is speaking on creating a resilient garden.
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