Friday, 27 May 2016

Understanding Soil Ecosystems

I've been doing a little research into soil ecosystems. After all, this is what my no-dig approach is all about - supporting those networks of life within the soil that help to keep it healthy and full of nutrients for my plants. And what I've found out has made me even more adamant that the no dig approach is the way forward. I've also learnt some very useful new tips about managing the soil in an appropriate manner for the type of plants I'm trying to grow.

My main source has been Jeff Lowenfels and Wayne Lewis's book 'Teaming With Microbes' and I would definitely recommend this book for anyone interested in finding out more about some of the science behind the no dig approach. The basic conclusions of their book are that it's important to look after the complex ecosystems in the soil as microorganisms in the soil readily provide all the nutrients our plants need to grow just as a by product of being alive. Different types of soil ecosystems exist for different types of plants and we can manage the soil carefully to encourage the system needed for whatever we're trying to grow.

Just think about it - no additions of man made fertiliser, synthetic or organically produced, are needed in an old growth forest. Thriving and abundantly healthy natural systems exist because of this soil based support system, which can only be found in undisturbed soil. Hence the no dig approach. As soon as you dig the soil, you smash up delicate networks of mycorrhizae, you throw deep soil micro organisms to the top and bury those that prefer to be at the surface. Whole hosts of organisms can't recover from this shock and are wiped out. Their complex interconnected networks have to be completely rebuilt. Additions of fertilisers, pesticides and fungicides are also lethal to this system. Intensively farmed soils are consequently all but dead.

But when they are left undisturbed, it's an amazing system and it's something that we can support through careful management practices.

The soil contains ecosystems every bit as complex as those in the rainforest, temperate woodland or coral reef, for example. All manner of beasts make homes alongside each other - predators and prey both visible to the naked eye and so tiny we can't perceive them without magnification. In a single handful of soil, there are more organisms than there are people on the planet. Think of the worlds of activity going on in a simple back yard with all that mini life hidden beneath the surface.

They're busy at it - living, thriving, hunting, scavenging, dying, eating, excreting, creating the basis of all live above their world - food for our plants.

The main organisms we're interested in are the smallest - the fungi and the bacteria. They consume the wastes of larger soil organisms and the wastes they produce are nitrogen based and form the bulk of soil-based plant foods. Fungi produce ammonium and bacteria produce nitrates. Both of these natural forms of nitrogen are in a plant-ready format and are more easily absorbed by plants than synthetic forms of nitrogen. Neither is washed out by rain water in the same way that synthetic fertilisers are, making more food available to plants.

And handily, the soils that fungi thrive the most in are those that support the types of plant that like ammonium based nitrogen - forest soils. Bacterially dominated soils - producing nitrates - support plants that are less woody and with typically shorter life spans- your vegetable garden or lawn, for example.

Here are a few top tips for encouraging the right kind of soil food web for your plants :

- for a bacterially dominated soil (eg the vegetable garden), use a home made compost with green plants as the main ingredient. Either incorporate this into the top layer of soil or use it as a mulch on top.

- for a fungally dominated soil (eg forest garden or shrub and perennial plant based flower bed), use a home made compost with brown materials as the main ingredient. A leaf mould is ideal. Apply as a mulch. Don't work into the soil. You can also simply add woody materials as a mulch- little piles or a mulch of prunings of twigs and small branches or even woodchips can all help tip the soil food web more towards a natural woodland type.

Monday, 27 April 2015

The Forest Garden Begins

At last, I feel I can say that we have a proper forest garden - albeit a very young one - and not just the little foresty bits around the edges that it's been for so long. We've been planning and working towards this for years, having started with an old yard covered in concrete. This winter, with soil preparations suitably advanced over part of the plot, it was finally time to get planting.

And now it's Spring, I'm enjoying watching them all wake up for their first year at Oak House.

So let me introduce you:

Walking along towards the forest garden from the house, we first come across the Medlar, welcoming us through onto the main pathway. This one is for David and I've promised to give it a try, but have to admit it sounds revolting - you apparently leave the fruit on the tree until they've putrified inside and then suck out the gooey middle. It apparently tastes a bit like caremel and David swears it's heavenly. I'll keep you posted!

The borders to the main path are yet to be planted, so we'll head along a little side path up onto the bank.

This is where the chop and drop soil improving plants have had a couple of years getting the soil ready for me and so this is where I've been busy planting out this winter. In the photo above you can see cocksfoot grass and red clover, both of which are fast growing and deep rooting, so help both break up my compacted soil and add lots of humus if I chop them back regularly. All the plants going in here are shade tolerant as this is the northern edge of the forest garden.

Next along this side path, we come across the Califonia Allspice - a suckering shrub whose bark can be used as a cinammon substitute. I can't wait to give this one a try!


This plant is normally dark red flowering, but I'm aiming for a more naturalistic woodland look, so went for a less exotic, green-white flowering variety called California Allspice 'Athens'. The flower buds are just forming now, as you can see above.

Along the path, I've planted several red currants - this is one of the best fruit bushes for shady areas, so planting it along the northern edge of my plot seemed a sensible idea.

In the background of the photo above, you can see one of my many broom plants. I have them scattered around, their main purpose being to fix nitrogen to feed all my growing plants. I also use them as a chop and drop mulch to improve the soil. Being a woody chop and drop, it's even better for helping to create a woodland type soil, feeding the kind of soil organisms you'd expect beneath trees.

Next to the redcurrant pictured above, I've planted a little aquelegia as an early perennial salad crop - the leaves are very good in a mixed salad in the early part of the year as the young ones are just emerging. It's also good for pollinating insects once it starts flowering in late spring. It's good here, as it tolerates part shade.


A little further along is an apple tree - Tom Putt - a good all rounder.

Travelling around the corner, past more red currant, we come to the lovely Lizzie Plum. Another one I can't wait for. I have to admit to being totally sold on the catalogue photo of the fruits of this one - big, juicy, dark red plums. Makes my mouth water just thinking about it! No flowers yet though, so I'll be waiting a while to try them.

This is underplanted with lupins for nitrogen fixing and pollinating insects.

Nearby is one of my honey berry bushes - these are a non climbing relation of honeysuckle, that produce blue fruits which apparently taste a little like blueberries, but with a honey aftertaste.

Last along the path is the Mulberry. I just had to have one of these as they are my all time favourite fruit. Like giant raspberries, but with way more flavour. Wonderfully juicy, a little tart and extremely more-ish.

Later this year, I hope to get a few more understorey plants in. I've not decided exactly what yet, but am looking forward to selecting a good mix of useful and edible plants. Comfrey, strawberries... Any suggestions are welcome!

Monday, 20 April 2015

Year round salads

One of the dreams I've been chasing in my garden over the last few years is to have year round salads without any effort at all. I'm quite a fan of a fresh green salad, but as a busy mum of two busy young kids, I struggle to keep a good succession of lettuce growing. Either the slugs get them, they go to seed before I find time to harvest them or I just don't find the time to get enough batches growing from seed to keep a regular supply going in the veg beds. So one of the goals of going perennial in the vegetable garden has been to sort this out. Latin names for all the plants listed are given at the end.

Having said I've been searching for year round perennial salad plants, two of my key players are actually annuals. Both of these plants self seed abundantly and between them, provide excellent supplies of lovely, mild tasting salad leaves year round.

For the autumn through winter, until early spring, I have Lamb's Lettuce.

And for the late spring, right through summer and to the early autumn, Mountain Spinach.

Right at the end of winter, my perennial rocket springs into life after its short winter sleep, so these plants give rocket leaves nearly all year round. After their first year, the plants reach a fantastic size, providing plenty of salad leaves for us from just one plant. Here is one of my plants, with just its early spring growth showing. By mid summer, this will be a sizeable bush.

Fresh, young Aquelegia leaves emerge around the same time. I initially put this plant in for its flowers, but it turns out the young leaves make a good addition to spring salads. This year I've planted some out in the forest garden. Here is one of the young plants getting settled in:

Primrose flowers, a lovely spring native, are another mild tasting and very pretty salad ingredient to brighten up those last wintry days in early spring.

Milky Bellflower sends up its leaves around April time and these can also be added to spring salads. The tall spires of large, bell shaped flowers that come later can make a pretty addition to summer salads, as well as looking great in the flower garden.

Sweet rocket (below) is used in the same way. This is a traditional cottage garden plant, which usually comes with heads of pink flowers, but here I have a white flowering variety.

Other edible flowers self seed around the place - we find plenty of calendula, the delicious nasturtiums and lovely, delicate tasting borage cropping up all over the the garden. I usually transplant them to a useful spot and weed the rest out.

And if that's not enough, I have various soft herbs that I often add for a little extra flavour. Two favourites are garlic chives for year round garlic flavour and sorrel, for a constant supply of zesty lemon tang.

If you're interested in any of these plants, here are their latin names, along with season of salading:

Lamb's Lettuce - Valerianella locusta - late autumn to early spring
Mountain Spinach - Atriplex hortensis - late spring to early autumn
Wild Rocket - Diplotaxis tenuifolia - late winter to late autumn
Columbine - Aquelegia vulgaris - spring
Primrose - Primula vulgaris - late winter - spring
Milky Bellflower - Campanula lactiflora - early spring and summer
Sweet Rocket - Hesperis matronalis - early spring to late summer
Marigold - Calendula officinalis - late spring to autumn (or through winter in mild years)
Nasturtiums -Tropaeolums - summer to mid autumn
Borage - Borago officinalis - summer to late autumn (or into winter in mild years)
Garlic chives - Allium tuberosum - year round
Sorrel - Rumex acetosa - year round

Monday, 13 April 2015

Minerals and plants

I've been doing some research into minerals and plants. I want to make sure the soil I've revealed from under all that concrete is now capable of being as productive as possible and I've found out a few things about how vitally important minerals are in keeping plants healthy.

Some key elements are calcium, magnesium, sulphur and silicon:

Calcium (Ca) - this element is linked to the pH of your soil, with higher pH soils usually containing more calcium. Calcium in plants is used in cell walls. Calcium deficiencies tend to be caused by a disruption in the supply, rather than a shortage in the soil. Causes can be a shortage of water (calcium is carried in the water the plant draws up) or excessive use of potassium or magnesium fertilisers. Calcium deficiencies cause blossom end rot in tomatoes and bitter pit in apples. They can cause die back or burn marks on young leaves and they lead to a loss of apical dominance.
Magnesium (Mg) - essential component of chlorophyll production and as a result is important in gaining high photosynthesis ability. High photosynthesis ability is key in increasing plant health and ability to resist pest and disease attack and also in increasing drought resistance. A deficiency of Mg shows up as green veined leaves with yellow between the veins. Found on older leaves first. Easy to confuse with virus attack and natural aging. Can be a problem caused by waterlogging, lack of water and compacted soils. Can also be caused by too much potassium being added to the soil or plant.
Sulphur (S)  - helps the plant to form important enzymes and plant proteins. Deficiencies cause yellowing of leaves, with oldest and highest leaves yellowing first. It is rare to find a sulphur deficiency.

Other trace elements include boron, iron, manganese, molybdenum, sodium, copper and silicon.

Boron (B) deficiency is one of the most widespread micronutrient deficiencies around the world. Boron is found in cell membranes. It affects the stability of cell walls as well as the ability of plants to take up other nutrients. It is particularly important in flower and fruit development. It is also important for photosynthesis as it affects the ability of plants to transport sugars away from the site of photosynthesis to where they are needed - for plant growth, fruit development, root growth and as root excretions. Sugars need to keep moving like this in order for photosynthesis to continue. Boron is also used in the development of root nodules in nitrogen fixing plants. It is also used in protein synthesis. Deficiencies in boron lead to poor plant growth and loss of fertility. Only very small amounts of boron are needed by plants. Too much is actually toxic, so efforts to increase boron need to be very careful about it.

I've been looking at different ways of increasing mineral availability to plants, including the use of mineral accumulators (or dynamic accumulators), foliar feeds and general soil mangement.

Mineral accumulators are plants that draw up minerals from the soil, accumulating them within their leaves - elements such as magnesium, copper and iron. These minerals can be made available to other plants by using the cut leaves as a mulch or by adding them to compost.

Here is a list of some plants and the elements they accumulate, with elements listed in order with higher concentrations first and with elements of significantly high concentrations compared to other plants listed in bold type.

Key plants:

Fat Hen (Chenopodium album) K, P, Ca, (also a little Fe and Na). Has extremely high levels of K. Has very high levels of P and Ca.
Amaranth (Amaranthus spp) K, Ca, P, Mg, Na, Fe (also a little Cu). Has pretty high concentrations off all these elements (except the Cu), especially Ca and K. Mg and Na are also present in relatively very high concentrations compared to a lot of other plants.
Stinging Nettle (Urtica dioica) P, S, Ca, N, K, Mg, Si Cu and Mo (also a little B). All the elements listed in bold are in higher concentrations than a lot of known mineral accumulators. Mg is also in relatively high concentrations compared to other plants.
Dandelion (Taraxacum officinale) K, Ca, Na, Fe, P, S, Mg, B, Mn (also Cu). Has much higher concentrations than a lot of other plants of B and Fe. Also high concentrations of Na, K, Ca and Mn.
Red Clover (Trifolium pratense) Mg, Mn (also B and Cu). Significantly high concentrations of Mg and Mn.
Lambs Lettuce (Valerianella locusta) K, Ca, Fe, Mg, B (also Na, Mn, Cu and Mo). Particularly high levels of B - one of the highest on record. Also very high levels of Fe and quite high levels of K.

Other useful plants:

Yarrow (Achillea millefolium) K, Ca, Mg (also a little Na, Mn and Si).
Borage (Borago officinalis) K, Ca
Feverfew (Chrysanthemum parthenium) K, Ca, Mg (also a little Mn, Na and Si)
Chicory (Cichorium intybus) K, Ca, Mg, Na (also Fe)

Sometimes minerals are readily available in the soil, but something is stopping plants from being able to access them. Careful management can stop this from being a problem. For example:
  • Improve heavy soils to make their rich nutrients more availble - add organic matter. Potentially add lime (or calcified seaweed) to encourage large particles to break down into smaller ones.
  • Shortage of water in the soil reduces mineral uptake - maintain a steady water supply and/or add organic matter to the soil and a mulch on top to retain water in the soil for longer.
  • Root damage by pests, diseases or waterlogging may make a plant unable to take up the food it needs. Add organic matter to the soil to improve drainage.
  • Too much fertiliser or lime can make some nutrients unavailable to plants. Be careful to only add food supplements if they are needed.

Tuesday, 7 April 2015

Spring Natives

I've got a bit of a native plant obsession going on at the moment. Actually, it's been building over the last couple of years, ever since watching Monty Don's around the world in 80 gardens and seeing the beautiful home garden by Chilean architect Juan Grimm, in which he uses native Chilean plants, planted just as they would grow in their natural environment - so it looks as though his house has been airlifted into a lovely, lush, wild and beautiful space.

So I've set myself the task of planting out my new back garden space entirely with native plants, to recreate the feel of our local native environment - those parts that are suited to a lawned back garden with a few trees and shrubs - country hedgerows with flower filled verges and the woodland edge. This area of the garden isn't very well developed yet, but nevertheless, this spring, there are all sorts of lovely native plants popping up and delighting me - one flowering now that I've only ever seen in photos before.

This is a wild tulip, native to the UK.

Having seen this flower open now for the first time, I can't believe I've not seen them around more often. I had to source the bulbs online as they aren't stocked in garden centres or in most plant nurseries. The flowers are beautiful right from the elegant flower bud stage. They're perhaps marginally more petite than cultivated tulips and the leaves are narrower. The flowers are flushed with green on the outside of the petals and are a rich spring yellow inside. Wonderful.

Elsewhere, I have some more familiar spring faces. Grape hyacinth pictured below, I have nestled beneath my silver birch tree.


Lungwort looks really bright planted here amongst the ivy

 Our native wood spurge is another good one for a shady spot. I'm looking forward to getting a decent spread of these - I love the colour combination of bright zesty green with the dark blue-green leaf.

Periwinkle is another shade lover and is great for ground cover. I found this lovely white flowering version in a local nursery and am trying to make more plants by allowing it to layer in to the ground, creating roots where it touches that can eventually be cut away to give me more plants. The stems can be used in basketry and I'm really keen to have a go once I've grown enough to spare a bit.

And I've planted loads of my all time favourite flower, the snakeshead fritillary.I just love the chequerboard pattern on the petals and the unusual, slightly boxy shape to those gently nodding heads. It comes in this pink colour and more rarely, it throws up white flowering versions with a white and off white chequerboard pattern. Very striking.


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