Why are the chilli plants a bit pale?

A south facing windowsill in March is no longer enough for the chillies in our lives. The leaves are a little limey in colour (especially the chinense types) and some of the plants just a bit leggy (especially the jalapeño and poblano). Without rushing for LED lighting and pinching out the tops just yet what can be done?

The key questions are would they do better in a warmer place? How can they get the most natural light? Do they need feeding more?

A bit of background information to give you a better idea of what we’re dealing with.

First temperature…

The chilli seedlings are currently in the house. You would hope that the house is a good temperature for the chillies to thrive. Monitoring with a maximum and minimum thermometer reveals that during the day, in particular cloudy days, the temperature can drop to as low as 17 degrees. At night an overnight low of…the same. Our house is pretty consistent.

In comparison, the heated greenhouse temperature has been all over the place. Sometimes 13 degrees at night, sometimes down to 5 degrees. It was zero outside but still, rather chilly for chillies! Sometimes 35 during the day. We have the smaller chilli plants in the greenhouse already. Although they are growing, they are no where near as advanced as the house ones. This is really the only other location we could consider putting the house plants. Perhaps quite yet.

Ideal chilli growing temperature range is 27-31 degrees. Well that is a hell of a lot hotter than these little babies have been getting. Time to raise our game and temperature. Off to turn the central heating on and research heating cables.

Now light…

Our two south facing windowsills can take five trays of twelve plants each but we have fifteen trays. The trays are on rotation to allow a fair share of being closest to the window and are lined up on a big table as close to the light as possible. It is March and we receive 12 hours of sunlight on a good day. However, on a double drip rainy day it can be really dingy. Clearly not enough light for those at the back of the class.

And then feed…

The plants are currently given a weak solution of Chilli Focus (5ml per litre) The bottle says they can be given 10mls per litre as the plants mature…perhaps it is time? Or maybe a nitrogen feed would be more suitable at this point and then switch back to the potash feed when flowers start to form. Or maybe Epsom salts might do the trick? Yes, a quick Google reveals that no harm can come from an Epsom salt spraying and a lot of good could be done.

Epsom salts are magnesium sulphate. Good for boosting chlorophyll production, uptake of nutrients and the ability to produce flowers and fruit. Best administered in a foliar spray it seems you can do no wrong with a misting of Espom Salts Wonder Spray (1 tsp per litre of warm water to aid dissolving).

The plan…

  1. The weather is turning from deluge of rain & 50 mph winds to cold and clear with some night time frosts. Until those frosts have passed we will have to stick it out in the house. It’s just not warm enough in the greenhouse.
  2. Keeping the central heating on in the house during the coldest days. The plants already come in off the window sills when the curtains are drawn.
  3. Moving the taller anuum type chillies nearer the windows to avoid any further legginess. The others will still be in the light. Turn the plants to encourage strong stems.
  4. An Espom salt spray will hopefully give a chlorophyll boost. Maybe that will compensate for the lack of prime window spots. We’ll continue with the Chilli Focus for now but…stop the press…a new click hole of banana compost has opened up. We get through a lot of bananas so this could be a good way to use the skins. We’ll report back.

True leaves

Time for an update on the 20 varieties of chilli we have growing here at The Birdhouse in sunny and blustery Hampshire, England.

A quick reminder of the seedlings’ journey so far…

The seeds were soaked in tea and left to chit in a humid propagator. Once the seeds had rooted & shooted they were put into small newspaper pots. They were kept fed and watered until their roots peeked out the bottom of the pots. Potted on into 9cm square pots. No science behind the square pot choice. We just have lots of them. They fit & balance well on our windowsill trays. And there we are, the story so far.

Chilli varieties with varying numbers of true leaves. Showing days since germination…

And if we do it all again next year?

We have not used heaters, reflectors, heated pads, lights or anything else too specialist…yet. Next year we might consider providing extra lighting once the seeds are germinated and potted up. A quick social media peek at specialist chillihead groups soon reveal the types of plant that can be grown under specialist UV lights with a little extra heat. Short, dark, glossy beasts that are poised to surge up when the frosts are finally over. Something to aim for.

Potting on the seedlings

A lot has happened since things kicked off this year. Our seeds were hot housed in the steamy propagator in the hope that germination would be quicker, more consistent and we would be a bit more successful with the chinense types. And things have indeed gone well. Hundreds of seeds germinated, hundreds of paper pots were made and now it is time to pot on the strongest of the plants to a more substantial home.

Paper pots
Germinated chilli seeds in their forever paper pots. Some seedlings just showing their leaves

How do we know it is time to pot on?

The seedlings are starting to show roots through the bottom of their paper pots. Many have two or more sets of leaves. The sun is shining in the UK and is forecast to be so for at least a couple more days. Perfect for a bit of window sunbathing to help the chillies settle in to their new pots. All good signs.

Seedlings ready to pot on

Using the specially formulated potting compost mix, the plants are tucked into 9cm square black pots. A layer of grit is put in the bottom and the paper pots are not removed, just buried within the new pot. Minimal root disturbance and the plants hopefully don’t feel swamped by the new pot.

Hey presto, 151 seedlings are potted on, fed and watered and basking in the sun.

Sunbathing in their new pots

Capsicum pubescens

Capsicum pubescens is a late entry to the heated propagator. Whilst using the last of our homegrown Rocoto chillies it was impossible to just throw the seeds away. So, they were introduced to the chitting pod. Having sworn we would get going earlier with the seeds this year, to allow the longest growing period possible, a quick diary check reveals that these seeds are starting off at pretty much the same time as last year. So much for planning.

Alberto Locato Rocoto

Four days later the roots have emerged. Much quicker than the chinense types and almost as quick as the speedy annuums.

chitted-rocoto-chillies
Chitted Rocoto seeds

And why did we bother with these seeds? Well, it turns out we’ve got a bit of a crush on these squishy fellas. There are far less varieties of Capsicum pubescens available on the market and you would certainly never see them in a UK food store to buy. The chilli fruit are all pretty similar with thick walls, juicy flesh and matt black seeds. With a round shape: some are a little more apple shaped, others lemony and some occasionally cheeked like bell peppers. Heat levels are medium to hot and they have a punchy fresh fruit flavour. They come in a range of -green-yellow-red but not purple or white. So far.

Capsicum pubescens are the smaller group of the five domesticated species of chilli. They are further away from others genetically. They trace back to pre-Incan times in Peru. In fact it is thought that the chilli remains found in the Guitarrero caves 10,000 years ago was a pubescens type. Historically significant as the chilli in question was found alongside evidence of campfires, grinding stones and human bones. It seems chillies were considered pretty valuable food stuffs. Not much has changed in 10,000 years then.

At The Birdhouse, we only grew one plant of this type last year: the high shine red Alberto Rocoto Locato. Gifted to us by my mother. It was easy to spot in the greenhouse as the plant grew differently to the others. For one, it had tiny white hairs on its leaves. Secondly, once it had got going, it split into two branches about 30cm up. It then sprawled out sideways and needed support from other plants. It snapped easily if knocked. It had bright violet flowers, with dusty white stamen. The chillies were late to set and took a long time to ripen to glossy red, maybe a 100 days or more. It matured about sometime similar to the Scotch Bonnets and they supposedly take 120 days. The plant was prolific despite being in a smallish 2.5 L pot. Whilst it was fed well it could probably have done with more root space.

Striking purple flowers

A quick bit of research tells us that these chillies are a fan of cooler nights, although still happy basking during the day. They are far more tolerant to lower temperatures generally. Although not frost tolerant. This bodes well for a UK climate and the need for a longish growing season. They are also long lived perennials, living up to 15 years. They can be climbers or tree formations. I think we might have a few Winter inmates this year. Let the pubescens journey begin.

The quest to find the best soil

Just which compost to choose for our precious chillies?

Loam. Peat. Coir. Grit. Vermiculite. Sand. Clay. Silt. Perlite. Manure. Compost. Sand. So much to consider.

The options are a little overwhelming but let’s dig down to what we know about chilli plants to see if we can come up with our perfect potting medium.

Cultural roots

Considering the geographical heritage of our chilli plants should hopefully give some guidance to the type of soil required for perfect chilli production. Chillies originated from Mexico. They gradually became mainstream as part of the Columbian Exchange in the 15th & 16th Centuries. A large percentage of the soil in Mexico is shallow to medium depth, dry, free draining, not layered or super structured, contains gravel, often fertile, pH leaning towards acid: 5.5-6.5. (Food Agricultural Organisation for the United Nations state that Leptosol, Regosol and Calcisol make up nearly 65% of the soil in Mexico if you want the scientific terms) Replicating this soil composition seems like a good starting point for creating the perfect chilli compost.

Back here in the UK

However, where chillies come from is not the only factor in soil choice. Surely where they are actually going to grow plays a part too. The UK offers a dizzying range of soil types, some of which would be incredibly inhospitable to a poor little chilli plant. Our Hampshire soil is about 6 inches top soil and then solid chalk. Not sure what our chilli amigos would say to that. A slightly acid, sandy loam in the South Hams of Devon would be perfect for growing chillies in the ground. With that in mind, we will be planting in pots.

Our UK weather is such that too much organic matter, such as peat or manure, silt or clay could easily become water logged and get cold. No one likes a soggy cold bottom, especially not chilli plants.

The potting soil in question will have two main functions for our plants: 1. to provide a habitat for our chilli roots to do their thing. 2. To be a vessel for the chemical requirements for great plant growth and chilli production. Let’s tackle each function separately.

A cosy home

We want the roots to have plenty of space to stretch out. Soil is typically 50% solids (mineral and organic) and 50% spaces, about half of which is occupied by water and soluble and suspended nutrients. A light, airy soil, with small particles would match the requirements. The roots can work their way through the gaps.

We will be gradually moving our chillies into progressively bigger pots. They sulk for ages if the pot size goes up too quickly. The indicator that they need to move home is when their roots poke through the bottom. Watering from the bottom should avoid compaction (which leads to a reduction of spaces within the soil available for root growth & essential gas, water and nutrient storage). Perhaps a layer of Horticultural grit in the base of each pot would avoid aforementioned sulky soggy bottom too.

Adding Perlite to the mix is another way to allow the soil mix to stay loose, encourage root growth and water drainage. No rotten roots here.

Feed the need

No great nutrient supply is needed from the soil solids as we will be feeding with Chilli Focus regularly. The organic components of the soil provided by the garden compost will ensure a good supply of microorganisms to exist alongside our chilli plants and work their bio magic. No doubt a few extra seeds will germinate as well but that is all part of the fun of doing things yourself.

We do not want too much green Nitrogen releasing organic matter. We hope to encourage good all round plant health and then fabulous flowering and fruiting. Extra Nitrogen may cause bushy green plants that forget to flower.

The seedlings are currently receiving a weekly feed of 5ml per litre of Chilli Focus. This will increase to 10mls per litre once a week when the plants have been pinched out and show some signs of flowers forming. At the height of flowering and fruiting the plants will have two feeds each week.

Vermiculite is another ingredient to consider. A natural product that is a good addition to any soil type. Added to clay soils it allows aeration and flow through the soil, reducing water logging and stunted or bound root growth. In sandy soils it soaks up water allowing retention where there would be very little otherwise. Good access to water, slowly released, means good access to those soluble and suspended nutrients. Sounds like Vermiculite is definitely going into our chilli mix.

So what does this all mean?

It’s looking like a hand mixed potting medium of 3/10 loam top soil, 2/10 coir, 2/10 organic homegrown well rotted compost, 1/10 grit for the bottom of the pot, 1/10 vermiculite to hold on to water and nutrients between watering and feeds, 1/10 perlite for free drainage within the soil. Probably very similar to John Inness No 2!

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Feeding time at the zoo

It’s time to give these little chilli seedlings a bit of what they fancy. They have been potted on into seed compost and are settling in admirably. The seed leaves are opening, they are a good green colour and generally they look healthy. The seed compost has no nutrients in it though.

Seven day old seedlings looking healthy after moving into their newspaper pots.

In the future we’d like to have a go at producing a homemade, maybe organic, specialist chilli feed. Using local ingredients. Perhaps with a seaweed enrichment? But not just yet.

Seemingly THE recommended chilli food is Chilli Focus. Containing ‘A precise formulation for optimal performance of chillies and peppers in pots, grow bags or the open ground.’ We used it all last season and the chilli plants and crop were spectacular. It turns out that Chilli Focus is ‘Made with care in the UK’, and ‘enriched with organic complex plant acids and pure concentrated extracts of kelp’ and comes in a 5 litre bottle, ‘enough for 1,000 litres of feed’.

With added Kelp extract

Err, sounds pretty good to us. Homemade fertiliser can wait for further research on a rainy (or snowy, check the forecast!) day.

The seedlings have been given a gentle dilute feed of 5mls per litre. This will be given once a week for now. Once the plants start to flower it will increase to 10mls per litre and then twice weekly when they set fruit.

Learning some lessons

An update, with added advice to self for next year:

The sprouted seedlings have been transferred to their paper pots, 135 of them so far. Thank goodness for grandparents and all their newspapers. The seed soil was cold and waterlogged (it is January after all) The pots were filled and warmed gently on the radiator.

Paper pots are quick to make and take less paper than you would think. Hopefully the pots will be soft enough for the first roots to break through meaning there will be no need to disturb the seedlings when potting on the next time.

 

Do not let the moisture in the chitting pods evaporate completely or the roots shrivel and dry. This has happened to Habanero Primavero Red. Hopefully some of the remaining seeds will germinate as we have no more in the packet. Not buying any more.

Also, don’t leave the sprouted seedlings too long in the chitting pods as their roots  become intertwined with the capillary matting. Some of the roots have snapped in the transferring process. Not sure whether they will survive or not but they will sulk for at least a week, no doubt. Maybe a vermiculite mix to germinate in would be best next year?