Why the delay in hardening off ?
Right now, in this Chilli growing season, I believe I should be further down the line. In previous seasons, I would have already completed hardening my plants off . by now. They would already have been prepared for exposure to outside conditions. Most would be permanently outdoors. Not so, this year!
I am not entirely sure why, but I am starting to get the feeling this year that my Chillies seem a bit smaller than on average. So far this season, we have not had a lot of sunshine in the United Kingdom. I suspect this may have impacted how well the Chillies are doing.
So how tall are my plants?
My tallest plants, the Longhorn F1s, Satan’s Kisses, Numexs and a Purple Tiger, are between five and eight inches. I started these from seed at the beginning of March. Many of my other plants, however, including Scotch bonnets, Prairie fires, Habaneros, Baraks and African Devils, are only still between two and five inches tall. Many of these were started at the same time as the tallest plants.
In addition, I did a second round of seed starting about two weeks later. The cultivars started were much the same as those mentioned above.
I accept that some plants are bound to be smaller if they were started later.
This is only to be expected. After all, seedlings need a certain time to grow.
I also acknowledge that slower-growing varieties like Habaneros and Scotch Bonnets will take longer to develop into mature plants. (Hotter varieties like these can take over a hundred days from potting on to reaching maturity). This is why it is important to start a growing season early with these varieties. Start too late and they will need to be overwintered.
Starting my Chilli growing season in March (a month later than normal) will obviously have had an affect. The plants will be smaller because they have less time to grow. The lack of sunshine has also had an impact
However ,taking everything into consideration ,somehow I doubt it . Based on previous years, my plants should be bigger than they are right now. They normally (dependent on cultivar) shouldn’t take longer than 90 days before they reach maturity.(Some even take less). These plants seem to be taking far longer to grow than normal this year.
Anyway, let’s wait and see what happens !
How to harden off Chilli plants
Toughening your plants
This size issue is partly why I am only now starting to harden off the taller plants for outdoor exposure. I normally wait until they are about eight inches tall and reasonably robust before starting the hardening off process. This year, however, I will start hardening off at five inches. This, of course, will only be if I judge them sturdy enough to go outside.
Hardening off plants for permanent outdoor exposure is done by taking the plants outside, so they can get accustomed to outdoor conditions. 
This process is done over seven to ten days. The plants are initially taken out for a couple of hours, then brought back inside. Over the subsequent days , they are taken out for gradually longer periods (about an hour longer each day) until they reach the point that they are left outside permanently. Hardening off should only ever be attempted when overnight temperatures are unlikely to drop below ten degrees Celsius.
The idea behind doing this is to gradually toughen up the plants. If they are left outside permanently too soon, they risk being damaged by conditions they are not used to. This may be too much sun, too much wind or rain. By taking them out for short periods in the beginning, and gradually increasing this exposure, the risk of this happening is reduced. They become accustomed to harsher conditions
Yesterday was the first day I took my plants outside. I left them there for three hours because it was overcast. Had it been sunny, I would have only taken them out for two hours. Today is cloudy again, so they will be out for four hours. I will continue doing this (with gradual increases) over the next nine days.
Final thoughts
The uncertainty about the size 0f my plants is not that unusual. As a keen Chilli grower, unless things are going exceptionally well,there is always some doubt. After all, growing Chillies in the UK is a race against time. To expect a good harvest, you would want your plants to bloom in about six weeks from now (about mid-August). I just can’t see this happening. Hopefully I am wrong. With all the time, effort and love that goes into growing these Chillies, you want them to do well.
Image credit : Marco Verch Professional Photographer / CC BY 2.0 / via Flickr