Moving out to the greenhouse: hardening off and the 9-degree night
The plants were ready before the weather was. By the middle of May they were 25 to 35 centimetres tall in 9-centimetre pots on the kitchen windowsill, with the first flower buds showing on the jalapeños and roots coming out of the drainage holes. The greenhouse is unheated, and the thermometer in there was still recording nights of 6 and 7 degrees. Chillies stop growing below about 10 and sulk for days afterwards, so I waited, and the plants got leggier and more tangled while I did.
Hardening off started on the 22nd of May: pots out to the greenhouse in the morning, back in to the kitchen at night, for a week. It is a tedious routine with fourteen pots and I missed one evening, which happened to be the night the forecast of 12 degrees turned into an actual 9. The next morning the leaves on the two habaneros were cupped and slightly purple on the undersides, and the smallest cayenne had dropped two lower leaves. Nothing died, but those three plants stood still for two weeks while the others got on with it.
Potting on into the final 10-litre pots happened on the 1st of June, with a mix of peat-free compost and about a fifth by volume of perlite, and a handful of slow-release pellets stirred into the top. The pots stand on the greenhouse staging on the east side, with the four tallest on the floor where there is more headroom. I water in the morning only, a litre per pot when the top centimetre is dry, which at this stage is every other day.
The shading was the other mistake. The greenhouse faces south-west and on the 3rd of June the maximum thermometer read 36 degrees by mid-afternoon. The jalapeños dropped four open flowers between them overnight. I painted the shading wash on the next morning, which is a week later than I had told myself I would do it last year as well. With the shading and the roof vent propped open permanently the peak has come down to 29.
At this stage, nine days after the move, the plants that were not caught by the cold night have put on 5 to 8 centimetres and are opening flowers, and I am pinching the first ones off the smaller plants so they put their effort into leaves for another fortnight.