Brightening up the dark December days

As we monitor the progress of the broadleaf salads being grown under the LED lights we continue to be impressed. Despite the dismal, dark and dreary days we have been having in the South West, growing under the lights our salads continue to shine.

The rich, vibrant mixed leaves of the Mesclun tray above grown under the lights, is the same age as the one below, in texture the leaves are succulent, rather than paper thin of the conventional tray.

Seen up close, the difference is even more apparent. The same can be said for one of our green salad leaves, Catalogna Cerbiatta, (below), denser growth, fleshy leaves, which again rich and succulent.

Up close, they too don't disappoint, with the true leaf so much more advanced and glossy.

Although slower to grow, the Red Cos leaves grown under the lights are blood red compared to rather watery and anaemic leaves of those under natural light.

It is very rewarding to think that not only will the salads will now take less time to grow, meaning we won't need to sow as many trays and have to dedicate as much space to them, they will also taste great and look amazing on the a chef's plate - as after all many of us eat with our eyes!

Spot the difference

It is now a month since we started to grow the baby salad leaves in the new polytunnel and using the LED lights to supplement daylight hours and we are certainly starting to see the difference. To try to ensure that we are operating as efficiently as possible we are trialling the use of the lights when the light is insufficient for growing and to extend the day.

We are currently monitoring the daily light integral, which is the cumulative amount of light received by the plants during a 24-hour period. We have a number of data loggers that provide a reading every 4 seconds and so when we see the light levels drop below a certain reading we know to switch the lights on.

The results have been very encouraging, with the leaves not only growing faster, but in a way that we have never seen before. The trays are fuller, brighter, more vibrant in colour and the leaves are of an amazing quality.

When compared with trays of the same age, grown in the main polytunnel without the use of lights the results are unrecognisable.

Despite being grown at the same density the trays are much denser and the leaves far more erect. In the main polytunnel the plants are more leggy as they look for light (on the right below), whereas under the lights the plants (on the left below), are putting their effort into leaf growth rather than stretching for light.

The colours are intense in the trays under lights and the leaves are far more succulent, seen on the left below:

The rate of growth is also very different between the two growing conditions, with the leaves developing much faster under the lights.

And when you look closely the difference is very clear, with far more advanced leaf growth (above in the photo below).

As for taste - the leaves are succulent, fresh and crisp. Cut daily for some of our local eating establishments, such as The Sheppey Inn and The Bocabar, they provide a rather unique addition to a variety of dishes, from speciality salads to high-end burgers.

All the results so far have been observed on trays that are placed on the floor so 171cm beneath the lights, however through the simulations undertaken by GN UK the manufacturers, it is recommended that the trays should be 145cm from the lights.

As a result, we are experimenting with trays at different heights and monitoring their daily progress, once they reach maturity we can then establish at which height the staging to support the trays needs to be. 

We now wait and eagerly watch with keen interest and excitement.

Water, water everywhere...

And now in our new collection tanks!
Setting up a rainwater harvesting system has been at the top of our list for some time, with our ultimate aim to put a large tank in the barn which collects the rain water off the large barn roof.

However in the meantime this recent spell of wet weather that we have been having in the south west has prompted us to think on a smaller scale and to utilise in the interim the tanks we initially bought for the aquaponics.

In addition to the barn there are several other opportunities for the collection of water, which include the main polytunnel and shade house. Not only is this an opportunity for free water it also means that we are able to reduce the amount of lying water on the ground caused by run off.

To set this in motion, Melv installed a system of guttering along the length of the polytunnel, which captured the water off one half of the plastic and which is also able to receive the water off the adjacent shade tunnel roof.

The guttering feeds into a blue barrel, which houses a pump operated on a float switch.

When the water reaches a certain height in the barrel, causing the float to rise, the pump is automatically turned on which then transfers the water into the 3 main tanks.

A very simple system, utilising all the equipment we already had, in just 5 days we have already managed to harvest in the region of 7,000 litres / 7 cubic meters of rainwater.

So although we have had to put up with some inclement weather of late, it doesn't feel half as bad when you are putting the wet stuff to good use - as they say every cloud does have a silver lining!!

Living up to its' name

Typically asparagus needs 3 years to reach maturity before it is ready to be harvested for the plate. Over those 3 years the plants are left to grow and flower, which is then cut back. Our plants in the tunnel are now in year 3 and at this time of year the growth and flowers start to die back and are ready to be cut and removed, leaving the plants open and clear in preparation for the new shoots to emerge next year.

Dominated by dead vegetation the photograph above illustrates that the polytunnel plants are ready for all the dead material to be removed.

Equipped with loppers the stems were carefully removed and loaded on to our small trailer, which were destined for the compost heap.

What a difference - with a huge amount of tall material removed, it let an enormous of additional light in, which is particularly significant at this time of year when the sun sets early and never manages to get very high in the sky for long.

Alongside the bonus of additional light, it also gave us an insight into how this particularly variety of asparagus earnt its name - Connovers Colossal  - which produces large thick spears which are claimed to have exceptional flavour. The picture below certainly demonstrates the large thick spears, as for the flavour, that is one of the treats of being in the horticultural business, of which we look forward to reaping the rewards.

Large thick spears indeed and next spring, we will watch with great excitement and expectation, when the new shoots will start to appear and we wait readily with our sharp knife in preparation for harvesting!!

Turning the Christmas lights on

With the new salad polytunnel now installed, next was the very exciting task of making the inside fit for purpose ready to receive the salad trays. With the intention of trying to control the humidity we lined the floor with damp proof membrane in an attempt to try to restrict the moisture coming up from the ground.

This plastic sheeting will need protecting from damage which could be caused both from walking on it and also from the light and so we paid a visit to our local floor covering company for off-cuts of carpet.

With just enough, the backs of the carpets provided excellent protection and just what we had in mind. Next was for us to decide on the best orientation for the seed trays, both to maximise the space but also to provide the access we needed to move trays around and for watering.

This is the tunnel that is going to house our new LED grow lights, which are going to hang off the metal hoops in two strips, held by sections of wire rope attached along the length of the tunnel. Melv began to fix the brackets ready to hold the rope in position. This type of fixing arrangement would mean that we had maximum flexibility to position each light where needed.

Once the rope was in place it took no time at all to hang the first 6 lights, with easy fixings via carabiners and wire cord each one could be hung where desired along the length of the tunnel. 

Guided by a simulation undertaken by GN UK, the light manufacturers, the lights were positioned pretty much under each hoop. Next it was the electrics, but again as a plug and play system the installation was straight forward and we were ready for the first trial switch on in no time at all!!

The lights are dominantly a red spectrum, which is the most desirable range for polytunnels and for supplementing natural light. Although there will be a degree of experimentation and adaptation, our initial intention is to operate the lights either end of the day in an attempt to achieve the light hours we need for baby leaf salad growth. The pink spectrum certainly looked most impressive from the outside and the pink illumination from each light was very visible.

However as darkness fell it was like nothing we had seen - WOW - it'll be the talk of the village - a warm pink glow exuded from the tunnel, much to the fascination of one of our more adventurous hens!

Once our electrician had completed a permanent electrical connection to the tunnel we were ready for the installation of the trays and to safely switch on the second strip of lights .

Realising that the distance from the trays to the lights may be a little experimental, initially we positioned the trays on boards placed directly onto the ground. This would provide us with the option to try different heights depending on how the leaf growth responded. With a number of trays in place and the electrics safe, we seized the moment for the big December switch on.

Inside, the lights made the tunnel and trays look rather eerie, but from the outside...

they look amazing - now we will monitor their performance and eagerly await to see how the salads respond - the prefect Christmas present for any horticulturalist!!