Arisaema is a genus of weird, witchy plants, such as Jack in the pulpit plant, that are in high demand. Find facts and information on growing, caring, and identifying some of the most popular Arisaema varieties.
Arisaema plants, as gardeners have discovered, are not as tender as their tropical looks might suggest. They have handsome foliage, which stands in splendid fettle after the strange, cobra-headed inflorescences have melted away.
There are more than 150 kinds in cultivation, but the most useful are the ones that are relatively hardy. Fortunately, beautiful Arisaema candidissimum and A. Consanguineum are among the kinds that can be grown quite easily in areas where winters are not too harsh. Use the taller species with equally imposing ferns, such as Osmunda regalis, Hosta ‘Krossa Regal’, and Thalictrum chelidonii. The smaller ones can erupt by mounds of Adiantum pedatum and the Himalayan maidenhair fer, A. Venustum. You will find some arisaemas sweetly scented.,
Cultivation of Arisaemas
The tubers should be planted in spring as this is when they are found in specialty catalogs. They should be set 10” deep into a moist, but well-drained soil that is rich in humus. A cool, shady location should be chosen. Arisaemas need to be planted deep because they send root from the top of the tuber, instead of from the bottom.
*If it is not clear to you which is the top or bottom, play it safe and set the tuber on its side so that the root will grown upward. They prefer the soil a little more on the acidic side if possible. You should mulch them with compost or leafmold in the fall or winter. If shade is hard to provide in your particular landscape, stick to Arisaema candidissimum, A. Consanguineum, and A. Jacqumontii, which can take more sun than the other varieties.
Arisaemas look great in containers and grow well in pots, provided they are big and deep enough. Use potting soil mixed with grit (two parts soil to one part grit) adding some well-rotted leafmold if you have it. Water freely once the leaves start to unfold, and apply a liquid fertilizer once a month. A top-dressing of crushed bark on the soil helps to retain moisture. Stand the pots outside, waiting in colder areas until all danger of frost has passed. Remember to bring plants indoors when the temps drop in the fall.
You should repot each fall, using fresh potting soil. Species with potentially large tubers, such as A. Griffithii, A. Speciosum, and A. Tortuosum, should be in pots at least 10”( 25cm.) across.
Deer, rabbits, and mice will leave arisaemas alone, because all parts, including the tubers, foliage, spathe, and spadix, all contain an unpalatable oxalic acid. The worst problems come from slugs and snails, which are particularly partial to the juicy spears of arisaemas as they come through the ground in summer.