Arisaemas in the Garden

This year I planted Arisaemas into the soil (in the garden) first time. In the earlier years, I've only grown them in pots, but I did not avoid the problem with tubers rotting. We'll see how this season goes well. So far, the plants keep quite well. I worry what will be the course of the weather. It was bad enough that it was quite a long winter. Long winter was followed by a relatively rainy weather and the next weeks weather forecast does not look good. Tubers are planted about 6 square meters. Garden soil I have modified 500 liters Baltic peat and gravel (100 kilograms, fraction:  4-8 mm ). Tubers I put on the gravel and I sprinkled them with crushed charcoal and then backfilled the hole with the soil. If the sun is shining I cover the plants with a netting that have 50% light transmission.

Seed germination – Lilium lankongense Franchet and Habranthus gracilifolius Herbert

The seeds of the two species I ordered via AGS Seed Exchange. I sowed them on January 1^st (L. lankongense), respectively on February 3^rd (H. gracilifolius). The seeds of both species germinated on March 13^th. I was a little surprised because sown seeds were placed on the stairs to the attic, in the dark, where the temperature ranged between 7 and 12 degrees Celsius.
Lilium lankongense is a species found in northwest Yunnan and southeast Xizang in China growing at altitudes between 1800 and 3200 metres. Normally, the seeds of L. lankongense will germinate within 15 to 35 days (http://www.the-genus-lilium.com/germination2.htm).

In contrast, H. gracilifolius grows in areas with mild climate - la Sierra de los Padres, Partido de General Pueyrredón, Provincia de Buenos Aires, Argentina (Echeverría, Alonso, 2010), southern Brazil, near Torres and Uruguay, near Punta Ballena and Punta del Este (Howard, 2001). Yet H. gracilifolius  is able to germinate at relatively low temperatures. At higher temperatures (around 20°C) but probably germinate faster (Echeverría, Alonso, 2010).

H. gracilifolius

L. lankongense

The photos of seedlings are taken less than a month later after germination. The plants are placed under the fluorescent lights that shine only during the day, at 15-18 °C.

New Arisaemas

Last week I received a shipment of new arisaemas. I had intended to plant bulbs in the garden, but some of them were already sprouting, namely A. nepenthoides and A. griffithii var. pradhanii. Because the weather is bad I planted them in the pots. I had a bad experience with the cultivation of these species yet. The tubers in one season always rotten in the pot. So I was inspired by the advice of Udai C. Pradhan´s book “Himalayan Cobra-Lilies (Arisaema) Their Botany and Culture” and I filled the pots halfway with crushed polystyrene. Then I poured a thin layer of coarsely crushed bark into a pot. I put a tuber on the layer and filled up a pot with substrate. I mixed substrate of light peat, compost and gravel (grain size 4-6 mm) in the ratio 3:1:1. I incorporated into the substrate a preparation against soil and other pests and crushing charcoal (as a disinfectant).

So we will see how arisaemas do well in pots this year….