Thursday, 12 March 2020

Crop rotations: the basics for urban growers

My kitchen garden and forest garden border now. The raised beds currently have garlic,
broad beans and corn salad. Now it's warming up, I can start more seed sowing
and really get the season going.
When I published my post on my crop rotation plans for this year in January, I got a lot of interest, particularly from people on Mastodon, who asked me a number of questions. So I thought I'd write a post covering the basics as my contribution to Solarpunk Action Week. The focus is on urban growers, as that's from where my experience comes.

Why rotate your crops?
Or, do you have to rotate your crops, even in a small garden? Yes, yes, you do.

The key principle of crop rotation is that you rotate plants of the same botanical family, which are prone to the same soil-living pests and diseases, and should not be grown in the same spot every year. The aim is to prevent the build-up of soil borne problems, such as club root, white rot, and eelworms, which often have no means of control (1).

If you continue to grow the same few crops in your garden or allotment, you risk a build up of diseases in the soil that might take years to get back under control. Particular diseases include potato cyst eelworms which affects potatoes and tomatoes, and club root which affects brassicas. Of course, in smaller gardens, disease can spread to other soil areas. Best practice is to do what you can to reduce the chance of this happening.

The other key reasons to rotation your crops is for nutrient availability/soil fertility. Vegetables have different nutrient requirements, so moving them around the growing area helps to avoid nutrient depletion in the soil (and remember, you'll be adding compost and manure/green manure each year to also improve soil fertility). Furthermore, rotating crops with alternating deep- and shallow-rooting vegetables, improves soil structure.(2)
A wooden raised bed sitting on top of acid soil.
The raised bed is filled with compost, giving it an alkaline-neutral pH. 

Does soil type (pH) matter?
The pH in soil matters because crop rotations are needed for annual vegetables, which won't grow in acid soil. A pH of 7.0 is considered neutral. An acid soil has a pH value below 7.0 and above 7.0 the soil is alkaline.

When it comes to perennial vegetables, few will have much of a problem with a slightly acid soil (pH 6-7) and some will be ok in pH 5-6. Below pH 5, you can only grow acid loving fruit and vegetables, such as most fruit, including blueberries and strawberries, or acid tolerating perennials such as sorrel.

If you have heavy acid soil (pH 5 and below), as I do, then building raised beds is the way to get around this to grow annual vegetables. My raised beds are 40cms high or more, allowing me enough depth to grow any type of annual vegetable.

Basic crop rotations
Crop rotations are usually practiced on a 3- or 4-year plan. If you have the space, plant your crops on a 4-year plan. For smaller spaces, go for a 3-year plan as a minimum.

For a simple 3-year crop rotation, divide your space into 3 sections or beds, then plant:
  1. Root crops (including potatoes, carrots, beetroot, garlic, onions and parsnips). You could include tomatoes in this group to keep the solanum family (potatoes and tomatoes), together.
  2. Brassicas (including cauliflower, broccoli, kale, radish, kohl rabi and cabbage).
  3. Legumes (peas, broad beans and beans). You could add the cucubits (pumpkin and squash) and vegetables that don't really have a group, such as corn and lettuce, here.
For a simple 4 year rotation, you would use the above, but separate out potatoes and tomatoes into their own group.

The garlic grew in this raised bed last year. This year I have created sections within this, and it
will contain a mix of broad beans, climbing French beans, squash and courgette, parsnip and beetroot.

However, even a basic crop rotation doesn't stay quite this simple, because plants have different seasons in which they grow. You plant garlic and broad beans in autumn and they'll be in their spaces from November to the following July-August. For example, one bed might have the following 4 year rotation:

Year 1: Broad beans Spring and Summer, then winter salads and green manures in Autumn and Winter.
Year 2: Peas, courgette and squash (the peas grow up, the courgette and squash underneath) for Spring, Summer and into mid-Autumn. Then plant garlic from mid-October, which will be  that will be there from October to the following July.
Year 3: Garlic up until mid-Summer, then salads and green manures for Autumn and Winter.
Year 4: Potatoes from Spring until Autumn.

After year 4, you return to year 1 and start again.

This photo shows an overview of a previous garden in mid-summer, 2015, which ran on a 4-year schedule. You can see how much you can fit into a small urban garden. The raised beds have been divided into roughly a metre squared sections, with different annual vegetables growing in each. The same view looked different next year as the crops are rotated.

Below are the plans I have, using a 3-year crop rotation cycle. Visit my post on crop rotations for my garden to see more detail.

Detailed crop rotations
Here's an example of crop rotations for a larger amount of beds, from a previous garden. This also includes a larger amount of crops, including brassicas and solanums. The beds were a mix of 3 smaller beds (1-3), and two long beds (4-8 and 9-13). The long beds were broken up into sections in order to make it easier to plan for crop rotations. This meant I could go with a 4 year rotation plan.

This is another photo from 2015, more clearly showing the different vegetables growing in different sections. In this space is: garlic, potatoes, climbing French beans, broad beans, parsnips, and carrots under white netting.

Final thoughts
You don't even need to start of with making big crop rotation plans as I do (I'm a bit of a nerd in that area). As long as you keep a record of what you plant, and where, each year, you'll be fine. Crop rotations can be flexible, just keep botanical families together. You can mix botanical families, but move them around the beds/rotations, together.

* * * * *
My thanks to Alison from Backyard Larder for information regarding growing perennials in acid soil.

1. Growing fruit and vegetables on a bed system the organic way, Pauline Pears, 2004, p25.
2.  Encyclopedia of Organic Gardening, editor Pauline Pears, 2001, p301.

Friday, 28 February 2020

Florespondence: Helle-not-so-boring

Hellebores, they aren't so boring. I'm sure that's been said a lot, but look at them - such beauty! The yellow ones are in the front garden, and the pinks and purples in the back garden.

Helleborus x hybridus Harvington yellow

A slightly chewed Helleborus x hybridus Harvington double yellow.

Helleborus 'Painted Bunting'

Helleborus x hybridus 'Double Ellen Red'

Helleborus x hybridus Harvington dusky, the second with the sunlight behind it.

Monday, 27 January 2020

Planning the crop rotations for the kitchen garden

The raised beds that form the kitchen garden.

The new growing season is fast approaching. As of this year I have my full complement of raised beds for growing edibles in, so I thought I better work out a crop rotation plan.

This is the layout, where I have numbered each section or bed, to make it easy to plan in order to know what crop is where.

As I have a smaller garden, I've decided to go for a 3 year rotation plan instead of a 4 year plan. I'll be going into detail about this in a future post(1). Here are my 3 year rotation plans.(2)

For my garlic, the plan is to only grow a larger number which I can then share, every 3 years. I may also grow some extra food in pots as well, depending on energy levels etc.

I have allowed for sowing green manure at different points in the year, and I'll continue to add some well-rotted manure and compost to the beds, as needed.

I'm not growing anything from the Solanum family (potatoes and tomatoes), and the only thing from the Brassica family (i.e. cabbages, cauliflower, broccoli) will be Kohl Rabi. In general, the Solanum and Brassica families require a lot more work than I have the spoons to manage. I've grown Kohl Rabi in the past and found it wasn't overly impacted by the white cabbage moth, so hoping that will continue, given they aren't easily available in the shops.

The asparagus, being a perennial, isn't part of the crop rotations as since it will stay in that bed for the next 20 years or so.
Looking at the kitchen garden beds from a different angle.

I suspect I may end up amending my plans as I go along, depend on my health. But having the crop rotations worked out in general, makes it easier manage what to sow where. Now, I'm just waiting for Spring!

* * * * *
  1. I'm putting together a post sumarising crop rotations (the reasons for, etc) for Solarpunk Action Week  (8th - 14th March). If there is an issue you'd like to see included, leave your request in the comments below.
  2. If you would like to see these in more detail, I've uploaded them to Scribd.

Saturday, 18 January 2020

Gardening with ME: plans for the kitchen garden this coming season

I've been mulling over what to grow in my veg beds this coming season. I decided to focus on the following categories:

A) veg I love but cannot easily get hold of from our local supermarket,
B) veg I love but makes good sense to grow yourself, and
C) some veg I love and just want to grow my own.

This might seem like I'm not leaving much out, but I'm pretty much excluding most of the large Brassica family, as I find them just too much work. In particular, dealing with the depredations of the cabbage white moth, even when using protection such as agricultural mesh. I'm not bothering with Carrots as carrot fly can be quite a pest, again, even when using protection. Anything (except pumpkin/squash, see C below) that requires lots of heat, which you can never guarantee in and English summer, is being left out. So no aubergines, cucumbers or sweetcorn.

In category A fit veggies such as Kohl Rabi, Fennel bulbs, Peas, Tatsoi and Broad Beans. Whilst peas are common, fresh peas are not, and the same with Broad Beans. I adore Broad Beans, and sowed some this Autumn past, and because of the mild winter, they have already taken off.

Some Broad Beans picked last year

Kohl Rabi, is part of the Brassica family, but from previous experience I've learned that it didn't seem to be bothered by pests, in particularly, the cabbage white moth. I'm growing it because it tastes good (roasted in particular), and I mean, how can you not grow it. It's purple. It looks like an alien. It's purple!

Mmmmm, purple Kohl Rabi

Roasted Fennel bulbs are divine. They have a licorice flavour, and even my partner, who doesn't like licorice at all, adores roasted fennel bulbs. I'm going to try Tatsoi because I do love making stir fry and the only place I can buy it requires a car journey.

The main veg in category B is lettuce. Not only do I find a lot of lettuce from the supermarkets bland, more importantly, it's easy to grow, and mine won't be covered in plastic. Lettuce is also one of those veg where one packet of seeds can supply us in salads for months. I'll be growing a mix of salads, including 'Bronze Arrow', a excellent cultivar from the Heritage Seed Library. I'm going to try and grow enough to save some seeds from these.

I also find Climbing and Dwarf French beans easy to grow and fresh beans are so good. The bonus is, if I end up not picking them, I can let them go to seed and then use those in stews in winter.

A pumpkin grown a few years ago

Finally, the those I just love, category C, which include my beloved garlic, but also courgettes and pumpkin/winter squash. Yes, pumpkins need a good period of heat and decent autumn. So this year, I stopped myself from ordering some Queensland Blue seeds (a massive pumpkin), and instead I'm just going to try a couple of the smaller cultivars such as Blue Kuri.
Of course, there is a proviso on any plans, my health. You cannot plan for the daily, sometimes even hourly, fluctuations and impact of ME. But I can plan for best case scenario, with the understanding that all might fall apart if the ME symptoms get worse. And to be kind to myself about this, if this is the case.

I've purchased the seeds I didn't have, some from Real Seeds and Seed Co-op, plus this years Heritage Seed Library seed choices have arrived. Now it's just waiting for it to warm up enough to be worth making the first sowings.

Sunday, 5 January 2020

Forest garden border: reviewing the first season

The L-shaped forest garden border along the south (left) and west (right) facing fences,
in July, prior to the new kitchen garden beds being created in front.

My forest garden border was first planted out in March this year, and I thought it would be useful to review it's first season. It's an awkward border to photograph on whole, so I tend to do it in sections, South (the left side) and West (the right side), which I'll use to refer to when discussing specific plants. A full plant list is at the bottom of this post.
The L-shaped forest garden border along the south (left) and west (right) facing fences,
with the just finished (in August) new kitchen garden beds in front.

I'm pretty pleased with the results from the first season. For a start, the blueberries already started producing, in particularly, Vaccinium corymbosum 'Hortblue Petite' on the South side. This was enough to add to several breakfast muselis.
First blueberry harvest

I had put up temporary netting to protect the fruits from the depredations of birds. However, this isn't an easy way to harvest, at least from an ME perspective, as it uses up more energy than you might expect trying to negotiate the netting and access the berries. So I need to make up a better long term netting set-up. I'm thinking of sewing my own netting cage together, I just need to work out the proportions, based on the size the blueberry bushes will eventually reach (about 1m square). A job for winter/spring.
Temporary netting around one of the young blueberry bushes

The Sorrel bulked up quickly and produced plenty of leaves throughout the season, which I have used in curries and other dishes. And the Rhubarb supplied a couple of kilos of fruit. We added manure around the crown at the end of the season, and will add more in Spring, to feed the hungry roots.

The comfrey has provided it's first harvest and I now have a bucket brewing (right) over winter that will give me comfrey tea, a homemade liquid fertiliser, to feed both edible and ornamental plants plants this coming season. Comfrey is rich in Nitrogen, which supports leafy growth, and Potassium, which promotes strong stem growth, flowering and fruiting of both edible and ornamental plants. I decided I didn't need two comfrey plants, so one has been dug up, and an apple tree has been planted in its place.

The apple trees were finally added at the end of November, after I chose and ordered three varieties at the October Apple Day that I attended. The trees that are all 4-5 years old, and there is a slight chance I might get fruit as early as next season. Fingers crossed.

The apple trees I chose were the following: Newton Wonder - double cordon (west-facing border)

Lord Lambourne (left) and Egremont Russet (right) - both single cordons (south-facing border)

A damson has been added to another part of the kitchen garden area. So not in the forest garden per se, but very close by (like, a couple of metres), so I thought it was worth a mention. I suspect it will be 2 or more years before I get any fruit off this tree. And I have planted some crocuses and daffidols in the border, so I get some early season pretty and the bees will have some food.

Overall, I feel like I've harvested quite a lot for the first season of my forest garden border. I'm not expecting to make any further changes to the planting and layout, so now all the plants can settle in and get growing for this coming and future seasons. And maybe, just maybe, I'll get a couple of apples next autumn?!

 Overview of the south-facing border in December.

Overview of the west-facing border in December

If you are interested in seeing how I planned the forest garden border, see my post creating a mini forest garden border.

* * * * *
Plant List
I've updated the plant list for the whole border, to include the recent additions.

Canopy layer
Apple trees: Malus Newton Wonder, Malus Lord Lambourne, Malus Egremont Russet
Prunus domestica 'Golden Transparent' (greengage)

Just outside of the Forest Garden border are also:
Amelanchier x grandiflora 'Ballerina' and Prunus insititia 'Shropshire Damson'

Shrub layer
Azalea (variety unknown)
Cranberry (variety unknown)
Vaccinium corymbosum 'Bluecrop' (blueberry)
Vaccinium corymbosum 'Hortblue Petite' (blueberry)

Perennial layer - edible
Akebia quinata
Foeniculum vulgare 'Purpureum'
Origanum vulgare 'Aureum' (golden oregano)
Rhubarb (variety unknown)
Rumex acetosa (non-flowering sorrel)
Symphytum x uplandicum 'Bocking 14' (comfrey)

Perennial layer - ornamental
Knautia macedonica
Lychnis coronaria Atrosanguinea Group
Omphalodes cappadocica 'Cherry Ingram' (ornamental)

Ground cover (plants mixed all around the border)
Ajuga reptans 'atropurpurea'
Allium ursinum (wild garlic/ramsons)
Armeria pseudarmeria 'Ballerina Lilac'
Crocus Etruscus Zwanenburg
Crocus Orange Monarch
Crocus Sieberi Spring Beauty
Cyclamen hederifolium
Fragaria x ananassa 'Samba' (strawberry)
Galanthus 'Ophelia'
Narcissus Brackenhurst
Narcissus Minnow
Narcissus Mother Duck
Narcissus Rijnvelds Early Sensation
Phacelia tanacetifolia
Primula vulgaris
Pulmonaria 'Blue Ensign'
Viola odorata 'Queen Charlotte'