For growing Lady-Slippers, Anemonopsis, Glaucidium, Paeonia japonica, Trillium grandiflorum:
Soil: Cypripediums like an evenly moist but well-drained soil and will not tolerate soggy conditions. Depending on the soil you are starting with, you may want to augment it. A 1/4 cup of lime may be added to each planting hole or dusted on top. If your soil is a heavy clay, you will need to remove it and fill the planting hole with a sandy loam like the mixture mentioned below. If, on the otherhand, your soil is a dry open, sandy type, you would want to add loam and humus. At the nursery we grow the lady-slippers and our other woodland plants in a mix of 75% gritty sandy loam and 25% composted bark mulch. However, a good loamy garden soil should be fine and not need much amending.
Mulch: A layer of mulch is very important. We use pine bark 3/4 to 1 inch deep with a light layer of pine needles on top. It will keep the soil cool and evenly moist. The soil should not be allowed to dry out completely, especially during the first year, as plants are getting established. Once the ground has started to freeze, we recommend adding a layer of straw or pine boughs to privide additional winter protection. This is especially important for fall plantings. Remove this extra layer in spring. If you live in an area that has wet winters, it is a good idea to cover teh newly planted cypripediums with something like a board or sheet of plastic to keep off the rain so they don't get soggy over their first winter. Don't forget to remove the covering in the spring before the plants come up.
Fertilizer: When planted in a good rich soil, fertilizer is not always necessary. However, you may wish to try a yearly spring application of a granular organic fertilizer. If you like to actively fertilize, you can apply a quarter-strength liquid fertilizer every 7 to 10 days from spring until mid-August. A yearly dusting of lime is always helpful.
Planting: Plants should be planted with the tips of their buds just below the surface (1/2 inch deep). Lady-Slippers should be planted with their roots spread out in the top four inches of the soil. Their roots tend to grow horizontally. Care should be taken when planting that the roots are not exposed to the sun or drying wind.
Watering: Please resist all temptation to over-water. These plants like an evenly moist soil and should be watered only through dry periods such as late summer. Like most other perennials, they should never be allowed to dry out completely.
For detailed photographs showing how to plant Cypripedium click here.
For Arisaema/Cobra lily:
Light, Soil, Fertilizer: As above except they do not need lime added to the soil.
Planting: The bulbs are best planted around 3 inches deep.