As the summer draws to a close and the autumn approaches harvest and processing is the order of the days. It’s cooled down somewhat here, but the dry heat continues and I’m really looking forward to a few days of cool rain so we can experience a final flush of flowering and growth before autumn decay and dormancy sets into the landscape. With few days of heavy rain it’s not uncommon here to experience something like a second spring in the final weeks of September.
We said goodbye to Jolanda and Paul last week who joined us for a few weeks and are returning back to the Netherlands to start a forest garden at their beautiful “eco” home that you can see here. Thank for all of your help in the gardens!
So… here’s what we’ve been up to this week.
Preserving and Processing
Aquatic Habitat Island for Rainwater Catchment Reservoirs – Katalepsis
Over at the crew house last week we finally got the rainwater guttering fixed (it has been detached since the spring) and now we just need some rain to fill the reservoir up. We have 2 down pipes from the roof draining into the pond on the east side of the house, and one 1000 L IBC tank on the west side with another down pipe diverting the water directly into the garden. Here you can see the reservoir on the east side of the crew house with the two down pipes diverting rainwater from the roof into the lined pit.
The roof catchment is approx. 58 m2 (one half of the roof) and our average annual rainfall is 538 mm. The clay tiles on the roof probably absorb light rainfall and brief summer rains so we take off 10% of the available rainfall in a given year when calculating the potential water harvest (catchment coefficient). According to the below rainwater harvesting calculation we can expect to receive 28m3 or 28,000L of water from rain collected from this roof .
|VOLUME (M3) = SURFACE AREA (M2) x AVERAGE ANNUAL RAINFALL (MM) x CATCHMENT COEFFICIENT (%)|
|SURFACE AREA (M2)||58|
|AVERAGE ANNUAL RAINFALL (MM)||538|
|CATCHMENT COEFFICIENT (%)||0.9|
|VOLUME (M3) =||28.0836|
The reservoir is almost empty now having been used to irrigate the garden crops for the past few months. Unlike the wildlife ponds we have built in most of our gardens, this reservoir is a basic rectangular shape in order to store as much water as possible in the space we had available. Rectangular water bodies do not provide the proper habitat for wildlife to flourish and can become breeding grounds for Mosquitoes due to the fact that frogs and fish that prey upon the mosquito larvae are unable to survive in such conditions.
So far we have placed a few logs in the water body for frogs to rest upon and added some floating plants but without banks and slopes and with the water level dropping drastically during the summer months (when we use the water and there is no rainfall to refill) there is no chance most aquatic plants and wildlife will survive. This being the case I thought we could build a small aquatic habitat island for the reservoir. Here’s how we did it.First we gathered the following materials:
- 1/2 a pallet
- 20 empty 1 L bottles with with sealed lids
- 20 m of 3 mm wire
- 22 aquatic plant divisions in 10 cm diameter x 10 cm deep pots (with holes in the bottom) – Plant species used were Sagittaria sagittifolia, Alisma sp. Carex sp. and Caltha palustris
- Saw to cut pallet
- Wire cutters
- Hose or rope to lower the pallet
The pallet with all of the bottles fixed. We also tied bottles in the gaps between the left and right planks of the pallet.
Before adding the plants we tested how well the pallet floated, lowering it in with a hose. It floated well, no need to add anymore bottles
We then pushed wire through the top of the pots and placed them in position. The wire threaded through the top of the plant pots will help secure them in place. The aquatic plants do not need the soil in the pots to survive as they will take their nutrients directly from the water, but for this to work it’s essential that the bottom of the plants pots are in the water. The soil should provide the extra weight needed to make sure the bottom of the pots are submerged. You could also use pebbles or sand.
With the plants in place we lowered the pallet back into water and the weight of the plants was enough that the bottom of the pots are underwater. We should have enough time left in the growing season to see the plants flourish and hopefully, if all goes well, the pallet below will be a mass of aquatic plants with frogs resting on the island and dragon fly larvae climbing the stems of the sedges to emerge as adults. The algae that will build up on the wood and bottles will also make good feeding for young carp. We’ll see.
Herb Rockery – Katalepsis
The team have been putting some love into Katalepsis, the garden over at the crew house, and have made a beautiful herb garden on the corner of the reservoir.
As all herb gardens should be, it’s located near at hand by the kitchen, and includes a number of perennial herbs as well as some annuals such as basil. The perennial herbs include the following:
In fact the garden was built last month by Shahara, Lea, Simon and Eva but I’ve not got around to taking photos until last week when we were building the aquatic habitat island. Thanks guys, it’s lovely.
Invertebrate Diversity Surveys – Aponia
The last five weeks we have been carrying out invertebrate surveys in Aponia (the market garden) looking at which of six habitat types host the highest diversity of insects, spiders etc. You can read more about how we carry out the surveys in our previous post here and I’ll be writing up a full report of these trials at the end of the season including the results, links to our record sheets, and copies of our protocol in case anyone would like to try the survey. Thanks again to Simon Leupi and Eva Goldmann for your help making the protocol for these surveys.
Here are some of the organisms from the pitfall traps and canopy observations. Thanks Jolanda for the photos.
We made 3 initial weeks of surveying to try out the method and develop the protocol that we are happy with for future use and started the official records 2 weeks ago. Based on the last two weeks of surveys it is very interesting to note the difference that 7 days without rain can have within nearly all of the habitats we looked at, with all but “late scrub” showing nearly 100 % more organisms with rain the day before compared to one week later without rain.
|Week 1 – 1 day after significant rainfall||Week 2 – 8 days after significant rainfall|
|Rank||Habitat||Number of Species||Rank||Habitat||Number of Species|
|1||Annual Polyculture||7.575||1||Annual Polyculture||3.775|
|2||Perennial Polyculture||6.5||2||Mixed Species
|5||Early Scrub||4.2||5||Mixed Species
|6||Late Scrub||1.85||6||Late Scrub||1.7|
Forest Garden Plants
Sambucus ebulus – Dwarf Elderberry fruit are ripe this time of year. This herbaceous species of elder, growing only to a height of 1.2 m grows well in full sun and in the partial shade of a woodland garden. It can also provide a good spreading drought tolerant ground cover and its clusters of pretty white flowers attract a wide variety of wildlife. The fruits and leaves are widely used in herbal medicine.
Lycopus europaeus – Gypsywort has found it’s way into the garden on the banks of our wildlife pond in Aponia. Unlike with humans, I absolutely love it when plants arrive unannounced. It is in flower from June to September and attracts a wide range of beneficial insects. The plant was used in the past to produce a black dye and is reputed to have medicinal qualities including use as a mild narcotic.