A most valuable greenhouse crop for those who love good food is Apium graveolens. An Umbellifer of marshlands found almost worldwide was known to the Ancients as Smallage. This was grown in gardens, or rather herbariums, solely for its medicinal use, until the Sixteenth century. Then in Italy this almost toxic plant was developed into a delicious salad crop. And not only a salad but one with wonderful flavour worthy of addition to soups and savoury dishes in seed, stalk and foliage.
Fortunately this aromatic plant is very easy to grow and with a frost free greenhouse you can harvest fresh leaves every day of the year. The foliage is lush and attractive if not showy and most conveniently the plants happily stand in large pots on the floor in shady positions.
You could start with seed though tiny so fiddly and as with so many plants there’s an easier way through vegetative propagation. And for this you can buy the salad version almost everywhere for it is a bunch of Celery.
That’s right, Celery. You see most folk think of this just as those crunchy salad stalks but those who know their cuisine understand how important the leaf and seed also are. You cannot make decent stock without onion, carrot AND Celery. Likewise the seed is an essential if elusive flavour in such as fine quiches.
Now it’s quite possible to start with seed and produce your own bunch of Celery though this will need exceptionally good growing (and blanching by wrapping to exclude the light and keep the stalks white). However from the cooks point of view the uneaten end of each stalk and bit of foliage is what is wanted for the pot. As is the fat crown at the base. But this part is more valuable for growing on. Just sit the base along with any remaining small stalks in a pot of moist compost, keep this moist and very soon it will re-root.
As you grow on this rooted crown it will furnish you fresh foliage for the kitchen over several months then will run to a flower stem and set seed. This in itself is also worth having as so good in egg and cheese dishes. Moreover you’ll see the old crown produces small offsets. These can be detached on and grown on for even more plants to replace the ‘mother’.