A Wonderful World of Weeds!
Just in case you think that only super perfect, weed free gardens appear on tv, we headed out to the Nano Nagle Centre to see what an acre of fertile ground in organic vegetables has to offer. Needless to say, there was plenty of weeds to peruse!
A weed is simply a plant growing in the wrong place. Weeds or wild plants growing in a field, hedgerow or forest are all part of the natural vegetation but if they are growing too close to your vegetables they will compete for water, nutrients and light. Potaotes can even be a weed if they rogueishly appear in your carrot drills! Competition leads to lower yields and if left unattended, weeds can take hold and strangle your crop completely. This is particularly prevalent to crops with sparse foliage such as carrots, onions and leeks. Weeds may also harbour pests and diseases which will in turn spread on to your crops, for example flea beetles living on charlock will spread to your other brassicas. Weeds may also cause a smothering effect and the lack of air circulation is the perfect breeding ground for fungal diseases such as mildew on onions. Some weeds such as stinging nettles and prickly thistles also make harvesting rather unpleasant. So it makes good garden sense to keep your crops weed free as it not only aids the aesthetics of your plot but it will also lead to more bountiful harvests.
Now weeds are not always our foe as many are medicinal and edible. Some are nutrient power houses, tasty in salads or cooked like spinach and grow absolutely free, without cultivation. Chickweed, hairy bittercress, dandelion leaves and fat hen are but a few and nettles are one of the best known Spring tonics for both humans and plants. Wild plants have always been used for cures and in traditional medicine. Make sure to check a reference book before adding any weeds that you are unsure of to your plate as some are poisonous such as groundsel, foxglove and nightshade.
There are plenty of ways of minimising weeds without nasty non-selective weedkillers. Rotations certainly help and also the stale seedbed technique of preparing your seedbeds several weeks before you plan to sow your crops so weeds can be knocked back before your growth starts. Green manures described below help and also the method of planting through ground cover such as mypex or using organic mulches like the straw I used on my edible hedge and onion bed.
It's best to keep on top of weeds when they are young and the golden rule is, 'ONE YEAR'S SEEDING, SEVEN YEARS WEEDING', so the message is don't let those weeds run to seed and spread their wares in multitudes and haunt your plot for years to come. Hoe, hoe, Hoe!!
We've all heard of farm yard manure, but what is a green manure you may ask? Well, it is simply a beneficial crop that you grow for a short while and dig into your soil before it gets a chance to set seed or fruit. If cultivated soil is left bare for more than a few weeks it will start to lose nutrients, be taken over by weeds, erode or become compressed due to rain and wind so green manures actually act as soil improvers and protectors.
It's a good idea to grow green manures over winter in beds that are empty. It will improve your soil, suppress weeds, and keep your garden going until you're ready to cultivate again in the spring. You don't have to restrict green manures to winter, though. They're also handy to give the soil a rest in between crops or as a first crop to break up the soil, increase its biomass, and get the soil life going.
Green manures are easy to sow, cheap to buy and make an excellent subsitute to animal manure, which is bulky and sometimes hard to find, especially if you are working an urban garden. Most good garden centres sell green manure seeds and they often come in mixes and will state whether they are suitable for summer or winter growth. They fall into three categories: nitrogen-fixing crops; quick growing leafy types and those with deep fibrous roots.
The nitrogen fixers which are the leguminosae family (Eg. Varieties of clover, common vetch, winter field beans and peas, fenugreek and lupins ) all have nodules on their roots which they use to take or fix nitrogen from the atmosphere into a form that plants can use. It's like magic and the good news is that your edible peas and beans do this also. So any pea or bean that you grow not only feeds you, but feeds your garden too by enriching the soil with nitrogen. Once you've harvested them, don't dig them up, but cut them off leaving the roots in the ground and as these rot down, they will release stored nitrogen into the ground for following crops.
The deep rooters (Eg. Grazing Rye, Phacelia ) improve soil structure by breaking up difficult soils and draw up nutrients from deep down which is dug back into the soil, adding nutrients and organic matter for following crops.
The quick growing leafy types (Eg. Mustards, Buckwheat) are useful between crops and many are up in days and are great for adding bulky matter to thin soils. These are mostly used in summer between crops.
Mustard and some other green manures, such as rape and fodder radish belong to the brassica family so make sure to watch your rotations and not to follow them on with any of your brassica vegetables.
Sowing My Green Manure
This week I cleared my broadbean bed so I wanted to sow a winter hardy green manure to keep the ground covered over winter. I chose a mix of grazing rye, phacelia and vetch. I left the bean roots in the ground and simply raked the soil around them, removing any weeds until I was happy with my seedbed. Then I broadcast (sprinkled) my seeds, covered them with the rake and voila my soil will be blanketed over winter until I need it for crops next Spring.
Incorporating Green Manures
The trick with cover crops is to dig them in before they flower or set seed. If you let them go too far the plant will have put all it’s energy into flower and seed production, depleting it’s value as a green manure and creating an even bigger weed problem for next year. The one exception I make is for phacelia as I always let a few go to flower as they’re blooms are so pretty and the bees and hoverflies just love them. Cut or strim your green manure growth next Spring, leaving it on your bed and then a few days after, dig it in to your soil. You should leave your green manure to decompose for about 3-4 weeks before sowing your crops as seed germination is inhibited by the crop’s decomposition.
August – Mid-October is the best time for sowing over-wintering manures. If you leave it too late, soil temperatures will have dropped, seeds won’t germinate and your soil will be left naked to the elements of winter!
Paddy (Parsley) Pesto!
Everyone’s familiar with basil pesto but alas without a polytunnel, it’s is not the easiest crop to grow in abundance in Ireland. But other herbs do and since pesto is basically a blend of oil, nuts, leafy greens, garlic (optional), parmesan and seasoning, it’s the perfect recipe for preserving and enhancing your nutrient dense greens for the months ahead. Wild garlic, coriander, rocket, kale, nettles, parsley – let your imagination and taste buds run free! Pesto is just delicious stirred into pasta, hot or cold, or with crackers and a good cheese, a dollop on roast veggies or a fish fillet – stop me now! I’m not a complete pesto puritan so I cheat and use a food processor instead of a mortar and pestle and I don’t follow any strict pesto recipe. Every batch has it’s own unique flavour depending on the ingredients I have in my kitchen, but it generally goes something like this:
2 cups tight-packed curly-leaf or flat-leaf parsley leaves. Remove the stems.
3/4 cup nuts (Pinenuts, almonds, walnuts, cashews – the choice is yours and toasting also gives yum flavour. You could use toasted sunflower or pumpkin seeds either.)
1/2 cup grated Parmesan cheese or a mature Irish cheddar (Optional)
2 large cloves garlic, crushed (Optional)
1 cup extra-virgin olive oil
Sea Salt & Black pepper to taste
Serve immediately or store in a jar in the fridge for a couple of weeks, ensuring it has a good covering of oil. Wipe the rim clean after each use and top up with oil. If you want to keep your pesto for a couple of months, you may prefer to freeze it in small plastic containers. If freezing, I do not add the cheese until I it is deforsted and ready to serve.
At this time of year, you might find yourself with piles of nutrient potent parsley that you would love to be enjoying all year round so why not whip up some pesto for you and your friends to enjoy!
A well known weather expert drops by with sad blueberry tales, expert grower Frank Bouchier will be giving me the low down on Seed Saving and of course, our gates and gardens are open from 10am on Friday 12th, so look forward to seeing you all here in Fota!