Raising Seedlings Under Grow Lights and Garlic Update

Garlic Update

The garlic grew all throughout the Canberra winter, and it appears that the hardneck types enjoy the climate more so than the softnecks. The hardneck types are quite large and robust, and the softnecks are wimpy in comparison. The plants have not yet sent up their scape, and are a few months away from harvest. 

It looks like I will have a good number of bulbs in a few months, hopefully enough to last many months!

Growing Nicely

Hardneck vs Softneck Garlic

Raising Seedlings in Canberra's Winter

This year I am growing a number of warm season crops, that require extended periods of warmth to produce, in particular super hot chillis and okra. In order to get the best out of the season I have decided to start these seeds early in an electric propagator under grow lights. I started many of my seedlings in early August, and am continually producing more, as space allows.

To make this process as easy as possible I retrofitted an old cupboard into a seedlings nursery.

An old wardrobe I picked up for $40 and converted into a plant nursery

The Wardrobe When Closed

The wardrobe is particularly useful in our cold winters as it stays between 20-20o C when the ambient temperature is cold, and on a warm day such as today (24o C) the hottest chamber sits at about 30-35o C with the door cracked open. 

I found out the hard way that keeping the door totally closed on a warm day can send temperatures in one of the compartments up to 40o C, and I cooked one or two seedlings in a fiery inferno of death.

Lets take a closer look inside.

Left Hand Chambers

The left hand side has a 250W high pressure sodium lamp with a reflector attached to spread the light.  

The bulb is enclosed in a cool tube, which is ducted to allow cool air to be drawn over the bulb and straight out of the wardrobe, on the right hand side, preventing over heating. This currently works very well, and if anything, the left hand compartment is slightly cool, and I rest some plants on a cardboard box to put them closer to the light for additional heat. I suspect that I could add a 400W bulb without too many heat issues, although as the ambient temperature heats up cooling will become more important. A fan attached to the left hand side of the cool tube is orientated to push air over the cool tube, rather than suck air through.

The fan is powerful enough to suck air from holes drilled in the right hand wall, cooling the right hand chambers as well as the left. The left hand door of the cupboard will drift open if allowed to do its own thing, however the suction is strong enough to keep the door closed as long as the fan is running. On several occasions I have come to find the door has drifted open after the fan goes off, and when it resumes there is no cooling effect in the right hand chambers, and in these cases the temperature has raised to 40o C quite quickly.

This compartment is large enough to hold two medium sized tomato or chilli plants, or one large wide plant. There is approximately 150cm of growing height.

Left Hand Chamber with 250W HPS and Fan Venting Air

Right Hand Chambers

The right hand chambers are split into three compartments; a storage place for the ballast for the HPS as well as all the power boards to operate the heated propagators and compact fluorescent lights, and two growing areas for seedlings and young plants.

The growing areas each have two compact fluorescent growing lights each at 130W, some in a blue-white spectrum, and some in more of a red spectrum. These CFLs produce about 8000 lumens each. These are very bright and leave you with stars in your eyes after looking for too long!

Two Seedling Raising Compartments

Red CFL vs Blue/White CFL

Lights on the Bottom Compartment

In the germinating compartments I have all the seedlings initially started in seed trays on electric heated propagators. I leave the covers on until the first seedling emerges and then remove it. The young seedlings in the above picture are fatalii chillis. 

The top compartment has okra, capsicum, eggplant and tomato seedlings and usually stays at around 30-35oC, the bottom compartment stays slightly cooler at around 25oC (door had been open a while at the time I took this picture so temperature reads a little cooler).

Various Seedlings in a New Larger home 

You can also see throughout the wardrobe I have used reflective silver sheeting and silver tape to maximise the light output from the globes. The sheeting comes on a large roll and is dimpled to prevent the formation of local areas of heat, known as hotspots which can cause heat damage to plants. I attached the reflective sheeting with a combination of glue and reflective tape. 

Light Timers

The lights within the wardrobe are on timers, which leaves the lights on for approximately 18 hours a day, and dark for 6 hours. I have the heated propagators on a seperate timer, with the mats going on for about 2.5 hours and then off for about 1.5 hours. This is because one heating mat was getting too hot and cooking seeds with 24 hour operation.

Timers and Exhaust Ducting

Potting Up Seedlings

I potted up a tray of my seedlings today as I felt they were large enough to be re-homed from the seed-trays they were germinated in. I potted them up in small pots from bunnings, 50c per pot.

When transplanting seedlings it is important to be extremely careful, and to try your best not to disturb the roots if at all possible. These seedlings had not seen natural sunlight before, and had not been hardened off in any way, and in such situations it is important not to leave them sitting in the full sun and wind for hours, as it may do damage to the tender plants.

Before Potting Up

After Potting Up

When potting up or transplanting seedlings it is important to consider the growth habit of each plant as this can affect the way you transplant. For instance the okra in the above photo have a tap root which if damaged will significantly stunt the growth or even kill the plant. Tomatoes on the other hand are much more resilient, and will even sprout new roots from the stem (still be careful though!). 

Tomatoes can actually be planted to just below the depth of the first leaves and this will strengthen the plant as it will develop a more comprehensive root system, sprouting roots all along its stem. Other plants will damp off and rot away if you plant the seedling below the depth where it originally grew. 

The plants above have been placed in a mixture of seed raising mix, bagged compost, perlite and diatomaceous earth. I also water them with a dilute solution of water and seaweed to help with transplant shock.

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The Great Container Mix Experiment - Part 3 Coconut Husk Chip Mix

In the mail today, I had my coconut husk chips arrive from an online store. The husk chips come in a compressed block which expands as you pull it apart and add water.

The brand that I have found available in Australia is designed for use in orchid growing and has been pre-washed a number of times according to the product description. It is important to have washed coconut husks, as they may otherwise contain high level of salts.

Coconut Husk Chips

I have no set formula for this following mix, and in the past have made it up using whatever ingredients I had laying around and whatever needed to be used up at the time. I really like the texture and feel of the coconut husk chips, as the mixes always come out light and fluffy, and you can just imagine the pockets of air that sit throughout. Coconut husk chips also hold water extremely well.

In general though my mix contains mostly coconut husk chips, but also pine bark, perlite and compost. I always add a little composted bagged manure as well.

I have a number of plants potted in this mix, some of which have gone dormant throughout winter, and some that have put on slight growth. Weed seeds constantly germinate however, and from pulling these out, it becomes easy to see how the roots of plants seek out the husk chips, and their roots grow into the husks itself, a property that pine bark can't match.

Plant Roots Grow Right Through the Coconut Husks!

My logic might not be quite correct here, but I think that if plant roots can not only take up the vacant space within a container, but also through the media itself, surely this will allow more overall root growth?! At the end of this experiment I will upend all the plants and compare the root development of each.

Today I also received with my order a bag of diatomaceous earth, graded to a 5-8mm size. This product looks similar to perlite, or a white rock, and is in a similar size. It has quite a number of properties that make it suitable for container culture, such as its ability to exchange nutrients, buffer soils, hold water within its porous body and will not break down over time, so it suits itself towards long lasting potting mixes. Both coconut husk chips and pine bark also are long lived, and a media made from these substances can often last a number of years.

I decided to add equal amount of perlite and diatomaceous earth to this mix, something I have not tried before.

Making the Mix

As mentioned above, coconut husk chips come in a compressed block. It is quite light, and I prefer to break it up with my hands before soaking it. I used a whole block with this mix, which makes up about 60-70L pure coconut husk chips.

Compressed Coconut Husk Chips

With the Help of a Screwdriver it Took Only a Few Minutes to Break This Up

The coconut husk chips expand quite a bit more once wet, so I split it into two container to mix up in two batches.

Once Wet the Coconut Husk Chips Almost Filled the Wheelbarrow

Once I split the mix I added two pots worth of large composted pine bark pieces. These pine chips were rated at 15mm, and are double the size of most of the pieces used in the 5-1-1 mix.

Two 8L Pots Full of Chunky Composted Pine Bark 

After the pine bark I added one pots worth of perlite, and one pots worth of diatomaceous earth.

One 8L Pot Full of Perlite

One 8L Pot Full of Diatomaceous Earth

Diatomaceous Earth Looks Similar to Perlite, it is Made Up of The Fossilised Remains of Diatoms

Next I mixed everything up and then added one full pot of bagged compost, and half a pot full of bagged composted chicken manure. I also added one handful of dolomitic lime, a small handful of Osmocote and two handfuls of organic Dynamic Lifter, for comparison with the other mixes.

One 8L Pot Full of Compost

One Half 8L Pot of Composted Chicken Manure

This is the final ingredient for this mix, so I gave it a really good mix with the shovel, and added a bit more water to any dry bit of husk I saw. 

The Final Mix Looks Like This

Close-Up of the Final Mix- Very Porous and Light

I added the mix to my pots and lined them up ready for the experiment to begin!

In these pots, the closest three will all be grape tomatoes, the next closest fatalii chillis, the third closest basil or silverbeet (or whatever catches my fancy!), and finally banana chillis.

Previously I said I was going to germinate each seed in its respective pots, but due to the fact winter is not over yet, I have thought better and will germinate all seeds on a heat-mat in my greenhouse until they are of a size to transplant. This will mean that the pots will stay vacant for several weeks. In the meantime I will keep them damp, so that they don't become hydrophobic.

All My Pots Lined Up Ready to Begin!

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