Saturday, 15 April 2017

Polyculture Study 2017 - Starting the Growing Season

After a long cold winter it's great to get started on the third year of our polyculture study and to welcome this year's team to the project.

Gabriele and Fergus are the first to join us, along with old friends Ute, Simon, Kartini, Marlene and Karl, who have purchased some land within an area we are working towards protecting. We've been pretty busy developing the new perennial polyculture garden, preparing the beds in the market garden and clearing plots for some new tree plantings.

Here's a review of what we've been up to in the market garden so far and in a future post I'll write about developments in the new trial gardens.

The Market Garden 

This year we'll be running three annual polycultures trials in the market garden, the usual Zeno, some changes to last year's Epictetus polyculture, and a variation on that theme called  Aurelius.

Produce from the gardens will be offered in veggie boxes from mid June - late November and we still have room for few more subscriptions. so if you are interested in a weekly fresh box of fruits and vegetables please send us an email.

Starting the Season - After the last harvest and end of season tidy up in November the market garden has been left to grow wild until the beginning of the new season in April. As you can see in the photo below a range of native plants establish on the beds providing some winter ground cover, excellent pollinator forage and a good supply of biomass that we chop and drop on the surface before applying the new mulch and plant out the crops.

The native plants on the edge of the beds are encouraged to grow throughout the year. They provide a partial buffer to the snails and slugs venturing in for our leafy crops, habitat to a range of ground dwelling invertebrates and a continual source of biomass as we mow them throughout the growing season and apply the trimmings to the surface.  

The annual beds have some excellent patches of native annuals providing early pollinator forage and habitat to a range of invertebrates.
Our first step of the new season is to take soil samples for lab analysis. It's encouraging to see Phosphorous (P) and Potassium (K) levels increasing and pH stable within the optimal range for vegetable production.  Even more encouraging is the jump in levels of P and K from the November analysis before any compost has been added to the beds and after harvesting over 330 kg of produce from the beds last year. See here for detailed report of last year's records.

Nitrogen mg/kgPhosphorous - Potassium mg/100g
March (before adding compost)pH (KCI)N03N NH4NP205K20
November (after final harvest)pH (KCI)N03N NH4NP205K20
Nitrogen mg/kgPhosphorous - Potassium mg/100g
March (before adding compost)pH (KCI)N03N NH4NP205K20

Soil analysis from March 2016 - March 2017  

A soil examination is used to assess observable properties of the soil. We use the Northern Rivers Soil Health card to do this and since records begun in 2015 we are seeing year on year improvements. See here for our records. The simple test looks at drainage, structure, soil biology, ground cover aggregate stability and more.

Gabriele and Fergus looking at the soil structure from one of 5 samples taken from the beds 

The next step is to get the beds ready for the incoming crops. First we apply a hand trowel (70-100 g) of wood ash (the remains of our winter fuel) per m2 of bed. You can read more about the benefits of wood ash in our previous blog post here. The beds are then lightly forked over to relieve compaction and remove any rhizomatous plants that may have established (such as nettles and mints) minimising the spreading of these plants in the cultivation zones. The rhizomatous plants go on a compost pile while all of the other local volunteer plants are cut at the base and applied as mulch to surface of the bed.

Forking over the beds to relieve compaction
Next we added compost to two of our beds, a wheelbarrow full is applied to the surface (approx 80L) of 3m2 of our beds i.e 26.5L /m2.

These beds will be used for two vegetable polycultures we are testing - Epictetus and Aurelius. The other four trial beds will host a polyculture we call Zeno. Two of the four beds will consist of the polyculture and two beds will be the same plants but planted in blocks (see below).

As there is still a thick mulch cover on the Zeno beds and the soil analysis shows high levels of  P and K, compost will be added to these beds when we plant out the crops as young transplants as opposed to blanket covering the entire beds with 20L per m2 as per usual.

We've had the tomato seedlings growing since late Feb inside the house under an LED grow lamp. It's good for keeping the seedlings upright indoors for initial stage before thinning and the 15 W lamp 50 cm by 50 cm can grow on 1000's of seedlings. The units cost around €25 each from ebay and has lasted 3 years so far without problems.

The first week of April we set up a hoop tunnel and transplanted the 4-6 cm high tomato seedlings. When they reach  15-20 cm in the hoop tunnel, around early May, we planned to plant them into their permanent positions. Unfortunately, I set the hoop tunnel up in the wrong place and an untimely wicked wind from the North flayed our plans and destroyed nearly all of the 450 or so tomato cultivars. So this year we'll be buying tomato transplants from the neighbours.  

Left - Right - Tomato seedlings under LED - Gabriele tilling the hoop tunnel bed before the seedlings go in - Fergus planting out the seedlings

The other crops such as beans and squash for the Zeno polyculture and control bed we'll grow in flats this year. In previous years we have sown in nests into the mulch but the cool and wet springs resulted in many of the Fabaceae (bean)  and Cucurbitaceae (squash) seeds (squash in particular don't tolerate heavy moisture) rotting in the ground, hence the change of plan.

Ute and Fergus filling the flats with a 50% compost 50% sand mix 
We're using flats with 28 cells of 70 x 70 x 80 mm per cell. Approximately 6 L of medium is needed to fill each tray. The medium we use is 50% compost 50% river sand which makes the trays quite heavy, but works really well for raising seeds and rearing on plants.

Many of our leafy crops were sown in a hoop tunnel in late March and will be planted into the beds when they reach 15-20 cm high. We're dense sowing a variety of salads directly into the beds for "cut and come again" greens and beetroots, swedes, parsnips and carrots as they don't appreciate transplanting.

Brassicacae hoop tunnel.

For a full list of annual crops we're growing in the gardens this years see below.

The Forest Garden 

The perennial plants are nearly all in leaf now and many are in flower. We've been topping up the mulch around the young trees including some new autumn plantings,  two Bulgarian cultivars of Apple 'Karastoyanka' and 'Aiviana' and two plum cultivars 'Angelino' and 'Santa Rosa'

A new nitrogen fixing element has been added to the forest garden Alnus cordata - Italian alder, that we'll be experimenting with on fast coppice cycles on one half of our irrigation swale.  Wild garlic has been planted into the Plum/Hazel thicket which hopefully will share the space with the existing Ivy, but provide a good spreading cover in the area during the spring in years to come.

Alnus cordata - Italian Alder 

The fruit trees in the gardens are all very busy reproducing and not at all shy about it either :)

Left to right - Peach - Plum - Crab Apple - Jap Quince and Pear 


Regenerative Landscape Design Course 

Annual Crop List for 2017

Latin name Common Name Familly
Tagetes erectaAfrican Marigold -AAsteraceae
Tagetes patula
French Marigold -A
Calendula officinalisPot Marigold Asteraceae
Helianthus anuussSunflowerAsteraceae
Lactuca sativaLettuceAsteraceae
Cucurbita pepoCourgette Zucchini
Cucurbita moschataSquash Waltham ButternutsCucurbitaceae
Cucurbita pepoSummer Squash
White Bush Scallop
Cucurbita pepoCourgette Zucchini
Black Beauty
Cucurbita pepoWinter Squash
Local Winter Squash
Phaseolus vulgarisFrench Climbing Bean
Cobra Beans
Phaseolus vulgarisFrench Climbing Bean
Hristo's Beans
Phaseolus coccineusRunner Bean
Phaseolus vulgarisDwarf Yellow Bean
Phaseolus vulgarisDwarf French Bean
Solanum lycopersicumRozava Magia Solanaceae
Solanum lycopersicumGolden Queen Solanaceae
Solanum lycopersicumBlack Krim Solanaceae
Solanum lycopersicumMixed Saved Solanaceae
Solanum lycopersicumBeaute Blanche Solanaceae
Solanum lycopersicumLocal Hierloom Solanaceae
Solanum lycopersicumTigerella Solanaceae
Solanum lycopersicumPaulina BG F1Solanaceae
Solanum lycopersicumMirabel -Yellow CherrySolanaceae
Capsicum frutescens ChilliSolanaceae
Ocimum basilciumSweet Genovese BasilLamiaceae
Pastinaca sativaParsnip
White Gem
Daucus carotaCarrots
Autumn King
Petroselinum crispumParsleyApiaceae
Anethum graveolensDillApiaceae
Apium graveolens var. rapaceumCeleriac
Giant Prague
Raphanus sativusRadishBrassicaceae
Raphanus sativusJapanese Radish
Mooli Minowase
Brassica napusKale - Borecole
Brassica napusKale - Borecole
Brassica oleracea Kohlrabi -
White Vienna
Brassica oleracea Kohlrabi
Purple Vienna
Brassica oleracea Broccoli
Romanesco Ottobrino
Brassica oleracea Broccoli
Eruca sativaRocket
Wild Rocket
Brassica junceaMustard
Red Giant
Brassica rapa subsp. rapaTurnip
Purple Top White Globe
Brassica rapa subsp. rapaTurnip
Milan White
Brassica napus subsp. rapiferaSwede
Beta vulgaris subsp. ciclaSwiss Chard
Rainbow Mix
Beta vulgarisBeetroot
Beta vulgarisBeetroot
Saved seed
Atriplex hortensisOrach
Saved seed
Allium cepaWhite Onion Amaryllidaceae
Allium sativumGarlic
Market Bulbs
Zea maysCorn
Zea maysCorn
Zea maysCorn
Popping Corn
Zea maysCorn

Our Annual Polycultures - Epictetus

Annual Polyculture - Epictetus

We tried this polyculture for the first time in 2016 (see here for results). It's basically a strip pattern of various vegetables from different plant families arranged to reduce pests and diseases, optimize space and nutrient share whilst respecting the individual plant needs for space and light.

Epictetus Polyculture in 2016

Epictetus Plant List - This year we have amended the plant combination slightly to allow more space for the plants. The following plants and cultivars will be grown in this polyculture. 

Lamiaceae - Epictetus
Dimensions - 23x1.2m
Area =27.6m2
QuantityRecount in JulyCropFamily Date Sown Date Planted
110Beetroot - Boltardy Amaranthaceae17/04/2017
71Dwarf Yellow Bean - "Rocquencourt"Fabaceae14/04/2017
35Kale - Borecole - 'Siberian' Brassicaceae28/03/2017
35Swiss Chard - 'Rainbow Mix' Amaranthaceae28/03/2017
220Parsnip White GemApiaceae07/04/2017

Our Annual Polycultures - Aurelius

Annual Polycultures - Aurelius 

This is first time we are trying this polyculture/  It's basically a strip pattern of various vegetables from different plant families arranged to reduce pests and diseases, optimize space and nutrient share whilst respecting the individual plant needs for space and light.

Solanaceae - Aurelius
Dimensions - 23x1.2m
Area =27.6m2
QuantityRecount in JULYCropFamily Date Sown Date Planted
220Parsnip White GemApiaceae07/04/2017
71Dwarf French Bean
Giant Prague
12French marigold
Tagetes patula

Friday, 24 February 2017

Soil Temperature and Seed Germination

A few days ago we sowed the tomato seeds for this season's market and home garden. It never ceases to amaze me what little indoor space you need to rear thousands of seedlings. We use two 50 cm x 30 cm x 15 cm trays to germinate approx 150 seedlings from 10 cultivars. When they get bigger we move them into two 1.3 x 8 m beds covered with polythene to rear them before they take their permanent positions in the gardens in early - mid April.

Tomato seedlings 

Many of the plants we grow I prefer to sow directly outside and one of the most important things to consider when sowing is that the temperature of the soil is high enough for the seed to germinate.

Other important considerations include:
  • whether the seed requires any pre-treatment before it will germinate, i.e stratification and scarification (mainly relevant for perennial plants particularly trees and shrubs).
  • how deep you sow the seed - too shallow is better than too deep. 
  • that the correct moisture levels are kept constant during the germination phase - not too wet, not too dry and with the ideal moisture levels similar to that of a wrung out cloth.

Elaeagnus commutata -  Epigeal germination 

This post we'll focus on soil temperature for germinating seeds. We'll look at why this is important, how to take soil temperature, and I've included a table showing the minimum and preferred soil temperatures for germination of some common plants.

Eruca sativa - Rocket germinating 

Often you will find a monthly guide on a seed pack indicating when to sow seeds and this generally works okay, but can be misleading. If you have a long cold winter and the soil is cold, germination will be delayed and in some cases the seeds may rot in the ground.  On the other hand, if the soil is unusually warm in the spring, it's possible to seed earlier. Being able to tell the soil temperature and being aware of the preferences of each plant will result in more or your seeds germinating.

Measuring Soil Temperature

You want to measure the temperature at seeding depth and this will differ for each seed you sow. The general rule is sow to a depth of no more than twice the diameter of the seed, but like I said above it's better to go too shallow than too deep.

Any thermometer that will measure temperature at a specific depth can be used to measure soil temperature. Insert the thermometer into the area where the seeds will be sown and wait a few minutes before you take a reading.

Bear in mind that each area of your garden will probably have a different temperature. The soil temperature is influenced by the following factors:
  • Bare soil warms much faster than mulched soil and vegetated soil.
  • Dry soil will be warmer than wet soils.
  • South facing soils will be warmer than north facing, and the amount of shade cast on the soil will affect the temperature considerably. 

Gingko biloba seedling 

Warming up the Soil

As the air temperature starts to warm up in early spring you may like to get a head start with your sowing and accelerate the warming of the soil. If you have a mulch on your soil for the winter you can temporarily remove the mulch. The dark coloured soil will absorb all wavelengths of light and convert them into heat, warming the soil much faster. Another alternative is to leave the mulch on and cover the bed with a plastic sheet or glass pane. On a sunny day this will provide considerable heat. Of course you can also remove the mulch and use the sheet or glass on the bare soil and this has the added benefit of germinating any seeds in the patch that can be pulled before you start sowing.

Here's a table providing the minimum and preferred soil temperature for a number of crop seeds and the estimated time it takes the seeds to germinate

 Minimum and Preferred Temperatures for Common Crops

Basil Seedlings

Would you like to join us for a course or event in 2017?