Growing Your Seedlings
OK, you’ve got your best seeds selected and you’re ready to start planting. What comes next?
What To Grow Them In?
I’ll state up front that I don’t know anything about hydroponics, nor do I know anyone growing chillies using that technique. As a result it will not be covered here.
Now that we’ve got that out of the way, there are two main points to be covered under this topic and they are; the medium to plant the seeds in and the container to hold the medium.
With regard to the medium I absolutely recommend using a premium potting mix or seed raising mix.
This is because these products are specifically designed with the following features; large particles to avoid compacting of the media which in turn inhibits both root penetration and drainage and, a nutrient profile that promotes vigorous root expansion and foliage growth.
You will inevitably come across people that tell you that the seedling needs to start off in the soil that it will eventually grow. That’s absolute rubbish, and if it was true would mean that there is no plant nursery industry as no one would buy anything in pots to take home. The fact is that the nursery industry across Australia turns over several billion dollars a year. Your garden soil is suitable for chillies that are well on the way to growing up, but is normally of a density, or contains diseases, that can inhibit root growth, damage, or even kill your new seedlings.
Now, as to containers, there is an enormous range and what is best for you is going to depend a little bit on how many plants you intend to grow and a whole lot on personal choice. Containers range from the individual Jiffy pots or blocks through the plastic 6 cells to large clay or plastic pots. We’ll examine each of these in more detail.
Jiffy pots and blocks are made from compressed sphagnum peat moss and wood pulp and uncompress and swell up once they are immersed in water. The seed can then be pressed into this swollen mass and, if kept moist, will germinate into a perfectly acceptable medium.
A big advantage of these is that when the seedlings are hardy enough to be planted outside, you simply plant the pot into the garden soil. There’s no need top remove the seedling from one medium to the other thereby reducing the stress on the young plant. The downside is that at around AUD$0.20 each, if your going to be planting a lot of seeds, the cost will start to add up, and, of course, they are not re-useable.
Now, the plastic six-pack cells are another option. You simply fill them with your seed propagation or potting mix, moisten, and put your seeds in each one using a dibble stick. Alternatively, three-quarter fill them then put a seed on top of each one and then put more mix to fill the cells. Either way is fine. The advantages of these are that they are cheap and re-useable which helps keep your costs down.
On the downside however, because they are small it is likely that you will need to transplant the seedlings into a larger pot before they are ready to go outside. The reason they need to be transferred is that the seedlings will rapidly become root-bound in the small cells and if they do, this affects the later performance and heath of the plant. It also stresses the seedling twice going from cell to pot to garden. If you are able to plant from cell to garden (as you may in the tropics) or if the plant is going to stay in the pot it gets transferred to, then these negative factors are not an issue for you. Congrats.
Now I’ll quickly look at pots.
I’m not going to explore cost here as it obviously depends on your personal choice and there is an enormous range available. If you are intending to plant into cheap plastic pots and then transfer to the garden at a suitable age that’s a perfectly acceptable process. The only downside here is that if you live in the colder parts of the country, you will not be able to fit many pots on a heating mat as discussed below. However if you are able to keep the pots warm some other way (e.g. heated greenhouse, or keep them inside the house) then this is not an issue for you.
If you plant the seeds directly into the pot that you intend to grow them in that’s fine too – the negative issues are only those discussed in the previous two sentences. On the plus side, the seedling does not experience any of the stress of transplanting.
Finally, just for your information I’ll quickly go over the basics of what the commercial nurseries do. They use a more involved process where the seeds are germinated in large flat trays with no medium other than some water. After a couple of days, the delicate seedlings are transplanted into the six-pack cells that you are familiar with. This maximizes the usage and saleability of the six-packs as there are no empty cells as a result of seeds not germinating. You’ve all seen the six-packs at the nursery where one of the seedlings has died and they just do not sell. So for the nursery to be able to avoid non-germination is worth the hassle.
Where Do I Grow Them?
You’ve got your seeds, raising mix and your pots. So, we now need to discuss where you intend to grow and subsequently acclimatise your seedlings.
I will quickly cover what I do first and then go over a number of possibilities for you to be able to choose the approach that best suits you.
When I do grow from seeds, which is not that often these days, I start off using a simple mini-greenhouse (see picture), with a premium grade potting mix, to germinate the seeds in, making sure it’s kept moist. This sits outside during the day where it will get sufficient sunlight and comes in at night to avoid temperatures dropping to detrimental levels.
As the seedlings begin to touch the top of the clear plastic lid (about 5cm high)
I transfer them to larger pots and place the outdoors against a galvanised iron shed, facing north. In this location they get plenty of spring sunlight and warmth, which is also reflected back onto the plants by the shed. Very occasionally Perth will experience a cold night or two during this time in which case I will either move the plants inside for the night or to a sheltered area where the temperature drop will not be as extreme.
Once I am happy that the plants are acclimatised and ready to go out on their own, I transfer then to the raised garden beds up at the back of my yard. The time frame for this varies and is as much about the future likelihood of damaging cold spells as it is about the readiness of the plant. This is usually around 3-6 weeks.
I need to say here that I avoid planting seeds too early (i.e. before October) which negates my need for a glasshouse or coldframe as discussed below. I can do this because Perth has a long, warm Autumn which means I still get a extended harvest season that lasts well into April and frequently even May.
If you live north of Latitude 35 S there is a good chance you can grow your chillies all year round, particularly on near the coast. If you live more than 200km from the coast you will need to be careful of low temperatures during the winter/dry season.
If you live between Latitude 30 S and Latitude 35 S (approximately Perth, Durban, and Santiago) you can adopt my technique above, or start a little earlier and borrow from the advice below, which is for the colder regions.
Should you live south of Latitude 30 S then you will need to read the information below and should look at getting your seeds to germinate in July/August to ensure you get a long enough harvest season to make the effort worthwhile.
OK. First thing to consider is that you will most likely need some form of heating to provide the temperatures your seeds need to germinate. There are several options here that I will discuss.
First option is an electric heat mat which come in both pre-set and adjustable temperature models. You’ll pay AUD$50-60 for the former and about three times that for the adjustable models. In Australia you can get these at good nurseries and garden centres. The Bunnings store (in North America the equivalent would be Walmart) near me does not stock them however, you are also able to buy them online at retailers such as http://www.gardenexpress.com.au (please note that we have no association with gardenexpress.com.au and if you look around there are other websites with the same equipment).
Friends that have these mats thoroughly recommend them. They have asked me to remind you though that once the seeds have germinated the heating mat needs to be placed somewhere that the seedlings will receive sunlight.
Another option is one that is quite popular with keen gardeners and that is the coldframe. The are an endless number of variations on the above example and they all work on the principle of solar heating of the medium in which you are germinating your seeds. Depending on how cold the climate is you may choose to open the up during the day and close them at night to retain the heat, or simply leave them closed most of the time to provide maximum warmth.
If your climate is extremely cold there are further steps you can take to heat the contents of your cold frame. One is to dig below the base of the frame and pack this with moist manure and straw and then cover this with a layer of loam and then place your potting mix/raising mix/cells/pots on top of this. Extra heat will then be provided by the decomposition of the underlying manure and you may be surprised by just how much heat this generates. I recommend you keep a thermometer in the frame to make sure temperatures do not get too much above 35oC. Cooling can be achieved by opening the sashes, of course.
In extremely cold climates you may wish to heat your coldframe electrically with a setup involving heating cables embedded below the base of the coldframe. I do recommend you get a qualified electrician to set this up as the consequences of a faulty DIY job could be fatal (and I’d hate to lose a subscriber!). Once a coldframe is modified in this way it is commonly called a hotbox.
The third and final option I’ll cover quickly is for those lucky enough to have a greenhouse. There is not a lot more to say regarding these that has not been covered in the previous three paragraphs. They are solar heated and this can be augmented electrically or by having some compost breaking down either under the floor or simply in a tub in one corner. There are a couple of points to be make sure of with regard to a greenhouse and they are; that the greenhouse is in a position to get sufficient sunlight through the winter months and, that it does not get too hot in the warmer months. Many greenhouses have panels that open to all the latter issue to be addressed.
Lets Grow Them
This is it. Everything is ready now to plant your seeds. The best time to do this is approximately two months before you believe you will able to put your chilli plants outside to fend for themselves, i.e. after they are acclimatised.
Fill up your six-pack cells or pots with your preferred seed raising medium, remembering not to pack the medium down as this will inhibit root growth. If you are using a premium potting mix this will already have sufficient nutrients to support the initial growth of the seedling. However, if you are using any other medium there is a high probability that it does not have the nutrient profile to support your young seedlings.
So you will need to apply a liquid fertilizer, of your choice, diluted for seedlings as the directions on the packet instruct. For those of you in Australia I use Powerfeed (TM) by the group that make Seasol (TM) (I have no association with them whatsoever, though if they want to cut a deal I am open to that).
I use a hand operated spray bottle to apply the fertilizer however some people prefer to soak the filled containers in the liquid for a few minutes. It’s up to you really.
Either way the germinating medium may compact a little here because of the liquid and this is not a problem however, if you need to top up the medium in some containers, do so.
Now with the blunt end of a pencil, or something of that size, push a hole into the medium in each cell, approximately ½ cm deep. Drop 2 or 3 seeds into each hole and then push a little of the germinating medium over them to cover. Depending on how many varieties you are planting you may want to label the cells or pots in some way so that you don’t need to try and remember which is which. If you keep a garden journal or almanac then you will no doubt be recording a number of data items regarding the planting. It is a good habit to have as the information you pick up over time can be significant for growing chillies in your particular area.
Now ensure that you keep the seeds moist and warm. Moist does not mean soggy, it means moist. Eventually you will see the seeds beginning to sprout. Let them grow for a week, keeping moist and warm and then, with a pair of scissors, cull all but the strongest seedling in each cell by cutting them off at the base. You want to do this to ensure that each generation of your chilli seeds is stronger and hardier than the last.
Ensure that wherever you have the seedlings growing gets sufficient light, heat and ventilation to ensure healthy growth. Fertilise your seedlings as per the directions on the packet/bottle – this is usually once a week.
It is incredibly important that you do not let the seedlings dry out. Seedlings that get stressed by dehydration early in their life seldom fully recover – you will end up with plants that have significantly decreased vigour and disease resistance.
Any electrical heating that you may be using can be turned off after about the third week provided the seedlings will not be exposed to the risk of frost.
After around six weeks your chilli plants should be of good size and looking healthy, and ready for planting.
Acclimatising and Transplanting Your Seedlings
If you have ever had an aquarium you will know that if you purchase new fish from the store and take them home you do not simply tip them from the bag into you tank and assume that everything will be alright. The temperature shock and the pH shock would compound the stress of travel and most likely result in dead fish with in 24 hours.
Your seedlings are the same. They are accustomed to the warm, lightly ventilated, constantly watered nirvana that you have raised them in. Basically they are complete wimps and need to be toughened up before they can be transplanted out into the big bad world.
In more technical terms they have grown rapidly, producing large cells with thin walls due to a lack of stress and environmental demand affecting the plant. They need to become accustomed to day-long exposure to UV light, strong winds, heavy rain, larger temperature variations and sporadic dry conditions.
Many gardeners call this process of toughening, or acclimatising, hardening off.
This is a process that takes place over two weeks once your seedlings reach an age of about six weeks.
The first step is to slow down the growth of your plant by watering and feeding less, and if possible, keeping the seedlings at a slightly cooler temperature. This will begin the adjustment stage by preserving the plants’ energy for adjusting to the new outdoor conditions.
Begin acclimatising your seedlings to the garden by gradually exposing them to outdoor
conditions. First expose them to filtered sun in the shade of a tree or in a sheltered spot protected from the wind and direct sun.Leave them for 3-4 hours and gradually increase the time spent outside by 1-2 hours per day until, bringing them back into shelter at night.
After a week or so, they should be able to withstand a full day of sun. While acclimatising the seedlings, watch them closely for signs of stress (the leaves may start turning yellow and drying out if exposed to too much sun). They should now also be able to stay out at night providing the temperature is not going to drop much below 10oC (50oF).
The science behind the process of acclimatizing your plants is a physiological one that adds carbohydrate reserves to the plant and produces additional cuticle on the leaves, reducing water loss. Practically, the process slows plant growth while acclimating the seedling to harsher conditions.
You’re seedlings are now ready to transplant and if you bought your seedlings from a nursery then this is the place for you to begin reading this document.
Before I get into the process of putting your plants in the ground I’d like to go over a couple of points about seedlings purchased from a nursery. The first is that these are frequently root-bound and if so, it will take longer for them to extend their roots into the garden soil, so they too are subject to wilting until they are established. Tease the roots our a little, being careful not to damage them, otherwise they will continue to circle around rather than spread out. Also, give them a little extra attention once they’re in the ground
The next point is that most nurseries indicate that their seedlings are acclimatised and ready for immediate transplanting. Instead of gambling and being disappointed (it was your money after all), harden them off yourself for at least a week first.
One more point to consider that, as a general rule of thumb, planting the same type of plant in the same spot year after year is asking for problems. The reason of this is that pests, because like their solanum cousins, tomatoes and eggplants, chillies are prone to root knot nematode. These are microscopic roundworms which attack the roots of the plant and cause it to wilt.
The two best practices for minimising this risk is to practice crop rotation or by adding significant amounts of organic matter to the soil at least annually.
The spacing between your plants depends on a number of factors, including the size of the varieties being grown. Smaller varieties, such as ornamentals, can be planted closer together and the there’s usually less sunburn (light brown burnt areas) of the fruit because they’re better shaded by the leaves. Some commercial chilli growers space their plants as closely as 10-15cm apart. Close spacing also helps minimize evaporation due to the thick canopy of leaves.
Now, to planting – generously water the plants to be transplanted the day before . This insures that the whole plant will be hydrated, leaves and all, when it’s time to transplant, thereby helping it to cope with stress.
Plan to do your transplanting when it is overcast or during the cooler evening hours.
Water the plant immediately before digging or removing from its pot. Soak the root ball so that the soil will adhere to the roots, when it is dug from the garden.
Never leave the roots exposed to sun, heat or wind. This is a risk if you remove all plants from their pots and simply lay them down, planting one after the other. It’s much better to remove them from the pots/cells just prior to planting.
Water the hole before you place the transplant into it. Place the transplant into the hole and fill it halfway with water. Allow the water to settle the soil around the roots and then finish filling the hole.
Lightly firm the soil around the transplant and again, water the whole plant, leaves and all. If possible, shield the new transplant from direct sunlight for 1-2 weeks, by cutting the bottom out of an old plastic pot roughly the same height as the seedling and place this over it. This will help the plant get over the shock by cutting down the direct light and also reducing evaporation. An extra plus is that it protects the plant from getting snapped off in strong winds.
Check the plant daily for the first couple of weeks. Transplants will need watering every day, if not more. If it is wilting, water the plant. Depending on the weather and the plant, you may need to water twice a day until it becomes established. The larger the plant and/or the less roots to top growth ratio, the more water will be needed.
All of this may seem extreme, but the shock of being uprooted is stressful to plants anytime of year. In the heat of summer, this extra precaution can make the difference between keeping and losing your transplants.
That’s it for this section. The third and final section deals with Problems, Pests and Diseases
Source by Nigel Laubsch