At the end of May most of the seedlings are put outside and left open to the elements, with the exception of those that do not like constant saturation of the foliage as they get older.
Lewesias and some of the primulas fall into another category that do not like summer rain as they take a little rest in the summer before starting into growth again in the autumn. The South African bulbs, which prefer to be sown in the autumn, germinate very quickly in the early spring and they usually stay in the alpine house until the weather starts to get warm. They are then moved to a cool north-facing frame to try and keep them growing as long as possible.
The onset of warm weather is a signal for these plants to slow down and go to sleep for the summer. So if you can keep them cool you will get an extra few weeks growth, it makes a big difference to the size of the new bulbs, and gives a much better survival rate. There are of coarse always a few exceptions, and some of the South African bulbs are quite content to grow on all summer, and tolerate our rather unpredictable weather conditions.
Cyclamen species are another group that benefit from a continuous growing season at the seedling stage, and will sometimes flower in the second year if they can be kept growing through their first summer. The same procedure as before is used, move them to a cool shady place before the hot weather arrives, and feed them every two weeks with the tomato fertilised as described above.
Bulbs must not be picked out at the seedling stage but left in the seed-pot for at least two years and fed as for the others, When it comes to potting on, the whole pot-full is put into a bigger pot and not divided out. Only after three years are they sorted out and potted individually if required. This is most important and must not be overlooked. I forgot to mention that the same procedure applies to the Cyclamen species if you want them to flower quickly, as they do not like disturbed in the early stages of growth.
